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AB - ORAL PRESENTATIONS O01. BEVACIZUMAB (B) PLUS IRINOTECAN (I) IN PROGRESSIVE TEMOZOLOMIDE (T) REFRACTORY GLIOBLASTOMA MULTIFORME (GBM): A SINGLE CENTER EXPERIENCE USING A LOW DOSE REGIMEN G. Dresemann, A. Dresemann, A. Hobbold; CTC-Standort Franz-Hospital, Dülmen, Germany Background: Standard treatment consisting of surgery, irradiation plus concomitant and following T is established in GBM with median survival of 15.6 months, indicating the need for further effective treatment. In several phase II studies B plus I showed impressive objective response rates (>50%) in pre-treated GBM pts with low toxicity rate, duration of response, however, was moderate. Therefore, B plus I might be an effective induction regimen for T resistant GBM patients as basis for further treatments. In colo-rectal cancer a lower dose of B plus I was effective, therefore B and I dose was reduced. Methods: From December 2006 to October 2007, 44 pts with progressive GBM resistant to T were treated with B 4 mg/kg body weight intravenously (iv) followed by I 80 mg/m2 iv repeated every 2 weeks. ECOG performance status (PF) was 0–2 in 43 pts, 3 in 1 patient. MRI scans were required at baseline (no hemorrhage was allowed) after 4 weeks and afterward every 6 weeks. Treatment was given until progressive disease (PD) or intolerable toxicity occurred. Results: All 44 pts were eligible for toxicity and efficacy; median follow-up was 7 months; 33 pts were male, 11 female; median age was 45 years (21–79); 32 pts had primary GBM; and 12 pts secondary GBM. All pts had prior irradiation (56–60 Gy); 4 pts had 4 prior chemotherapy regimens, 11 pts 3, 22 pts 2, and 7 pts T only. The only patient with PF 3 died of clostridium sepsis during grade IV leucopenia after the first treatment; 1 patient developed grade III leucopenia; 2 pts grade III thrombopenia; 1 patient grade III pneumonia; 2 pts asymptomatic intracerebral bleeds requiring treatment delay; and 1 patient grade III fatigue. In 22 pts a partial response (PR) was achieved; in 15 pts disease stabilization for at least 2 months; and 7 pts showed primary PD. Median duration of PR was 3 months (2–8); best MRI response was acchieved after 4 to 8 weeks of treatment. Data will be updated. Conclusion: B plus I seems to be the most effective regimen for induction of objective response in multiple pretreated GBM pts with excellent toxicity profile. Efficacy of the low dose regimen was comparable to other published regimen. In targeted therapy the principle of maximum tolerated dose (MTD) is not necessarily identical with the optimal treatment dose (OTD) which might be much lower. Confirmation is required. A following maintenance treatment should be considered. O02. EVALUATION OF THE EARLY ANTIANGIOGENIC ACTIVITY OF SUNITINIB MALATE BY PERFUSION CBF AND CBV VALUES FROM DSC-BASED PERFUSION IN RECURRENT GLIOBLASTOMA C. Chaskis, M. Dujardin, A. Michotte, B. Neyns; UZ Brussel, Brussels, Belgium Background: Primary as well as secondary glioblastoma typically exhibits striking neo-angiogenesis with elevated expression of vascular endothelial growth factors (VEGF) and their receptors (VEGFr). These signals promote aberrant blood vessel formation by recruitment of endothelial cell precursors and facilitate sustained tumor growth. Associated edema within the tumor and surrounding normal brain is a major cause of disease-related symptoms and morbidity in glioblastoma patients. Sunitinib is an oral small molecule that inhibits the activity of the VEGFRs, FLT1, FLK1/KDR, PDGFR-a and -b, c-Kit, and the FLT3 and RET kinases. Methods: We evaluated whether sunitinib at a continuous daily dose of 37.5 mg is capable of attenuating intra-tumoral VEGFr-mediated signaling, thereby causing antiangiogenic and antiproliferative effects in patients with recurrent glioblastoma. We assessed the antiangiogenic response after 4 weeks of sunitinib therapy by calculating the cerebral blood volume (CBV) and cerebral blood flow (CBF) from dynamic susceptibility (DSC) based perfusion MRI. We compared the CBV and CBF values in the whole tumor, in the contra-lateral white matter, as well as the lesion-to-normal-white matter CBV (CBVLTN) and CBF (CBFLTN) ratios. Results: As part of an ongoing phase II study, 21 patients with recurrent GBM were recruited since July 1, 2007 (median age 43 [range 34–71], M/F 15/6). All patients had progression following surgery, radiotherapy and temozolomide chemotherapy. Nineteen patients have initiated study treatment and results are available on 16 patients. Sunitinib resulted in early anti-angiogenic effects in 6 patients that were manifested by a clinical improvement with associated early decrease of CBVLTN and CBFLTN (p<0.05, r =–0.683). In 2 responding patients, the treatment was interrupted because of grade III or IV hematological toxicity, with subsequent tumor progression. One of these 2 patients was able to resume sunitinib, with again a rapid clinical improvement. In this particular patient with a durable response on sunitinib, reduced amino acid metabolism was documented by 2-18F-Fluoromethyl-L-Phenylalanine PET-scan differentiating true cytoreductive activity from a steroid-like effect. Despite continued therapy, all other responding patients had PD within 4 mths. Four additional patients have remained clinically stable at the latest follow-up (<4 mths) and 6 patients had immediate progression. Artefacts prevented an adequate interpretation of perfusion imaging in 3 patients. Conclusions: DSC based perfusion MRI seems valuable in measuring the early antiangiogenic activity of sunitinib (37.5 mg on a continuous daily dose) in patients with recurrent glioblastoma. Sunitinib causes early reduction in CBVLTN that correlates with an improved clinical status. O03. TEGWONDO—DEVELOPMENT OF A NOVEL NEAR-CONTINUOUS DOSE-DENSE TEMOZOLOMIDE REGIMEN FOR THE TREATMENT OF RECURRENT GLIOMAS H. M. Strik1, J. H. Buhk2, C. Bock3, M. Nitsche4, A. L. Hoffmann1, A. Wrede5, C. Marosi6, U. Kaiser7, M. Christmann8, B. Kaina8; 1Department of Neurology, Göttingen, Germany, 2Department of Neuroradiology, Göttingen, Germany, 3Department of Neurosurgery, Göttingen, Germany, 4Department of Radiation Oncology, Göttingen, Germany, 5Department of Neuropathology, Göttingen, Germany, 6Department of Oncology, General Hospital, Vienna, Austria, 7Department of Oncology, Hildesheim, Germany, 8Department of Toxicology, Mainz, Germany Background: We report on activity and feasibility of a rechallenge of recurrent gliomas with temozolomide (TMZ) in a dose-dense 21/28-day regimen and development of a novel 5/7-day schedule. Methods: 40 recurrent glioma patients received TMZ 100 mg/m2 with individual dose adaptation: 21 pts. received 148 cycles days 1–21/28 (18 WHO IV [GBM], 3 WHO III). GBM pts. had a mean age of 54.4 y, median KPS was 60%. Patients with critical blood counts (∼50%) were switched to a 1–5/7-day regimen. Better tolerability led us to treat 19 subsequent patients initially days 1–5/7: 13 GBM, 2 WHO III, 4 WHO II; 55.5 y; KPS 70%; total 61 cycles. All malignant gliomas were pretreated with temozolomide. Results: Nausea and fatigue were less frequent than with the 5/28-day schedule. Blood counts usually decreased continuously. Dosage was reduced in approx. 50% of patients and increased to up to 130 mg/m2 in 3 patients. Hematotoxicity grade 3/4 (asymptomatic): 2/21 pts. (21/28-day) and 3/19 pts. (5/7-day); nonhematological 3/4: 4/21 pts. (21/28) and 0/19 pts. (5/7). Efficacy of 21/28-day application in GBM was: 3 CR (17%), 1 PR (5%), 7 SD (39%), and 7 PD (39%) for at least 3 months. Progression-free survival at 6 months was 38.8%, at 12 months 22%, and at 24 months 6% (1 pt.). Survival after relapse was 34.8 weeks and overall 17.9 months. 3/6 pts. with unmethylated MGMT were progression-free >12 months. Conclusions: Rechallenge of recurrent gliomas with dose-dense temozolomide initially at 100 mg/m2 and individual dose adaptation is feasible and active. 22% of objective long-term responses demonstrate that this strategy is effective even with unfavorable prognostic criteria. Dose adaptation is most appropriate with a near-continuous application days 1–5/7, which is expected to cause permanent depletion of the alkylation-resistance factor MGMT. In fact, patients with unmethylated MGMT also had long-term responses, indicating that chemotherapy resistance may be overcome with this strategy. We therefore consider TEGWONDO (TEmozolomide Glioma WOrkiNgday DOse-dense regimen) to be active and feasible also in TMZ-pretreated patients with critical blood counts. O04. THE TEMOZOLOMIDE RESCUE STUDY: A PHASE II TRIAL OF CONTINUOUS (28/28) DOSE-INTENSE TEMOZOLOMIDE (TMZ) AFTER PROGRESSION ON CONVENTIONAL 5/28 DAY TMZ IN PATIENTS WITH RECURRENT MALIGNANT GLIOMA J. Perry1, W. Mason2, K. Belanger3, P. Kavan4, D. Fulton5, J. Easaw6, S. Kirby7, D. Macdonald8, C. Shields9, J. F. Pouliot10; 1Odette Cancer Center and Sunnybrook Health Sciences Center, Toronto, ON, Canada, 2Princess Margaret Hospital, Toronto, ON, Canada, 3Hôpital Notre-Dame, Montreal, QC, Canada, 4Royal Victoria Hospital, Montreal, QC, Canada, 5Cross Cancer Institute, Edmonton, AB, Canada, 6Tom Baker Cancer Centre, Calgary, AB, Canada, 7QE II Health Sciences Centre, Halifax, NS, Canada, 8London Regional Cancer Program, London, ON, Canada, 9Hôpital Enfant-Jésus, Quebec City, QC, Canada, 10Schering Plough Canada, Kirkland, QC, Canada Background: The combination of radiation with temozolomide (TMZ) 75 mg/m2 × 6 weeks + adjuvant TMZ 150–200 mg/m2 given 5 days out of 28 (5/28) is the standard of care for glioblastoma multiforme (GBM). However, a large proportion of patients will progress after this primary intervention and second-line regimens are modestly active at best. Continuous dosing and dose intensification have been shown to decrease levels of O-6-methylguanine-DNA methyltransferase (MGMT), which has been associated with TMZ resistance. Thus, altering the schedule of TMZ administration and dose intensification would appear to be a reasonable strategy to reinduce response. Methods: After signing informed IRB-approved consent, patients with high-grade glioma who failed the standard TMZ 5/28 adjuvant regimen received continuous dose-intense TMZ 50 mg/m2 for 28 days out of 28 (28/28) for up to 1 year. The primary endpoint was 6-month progression-free survival (PFS). The trial used a two-stage design in which at least 1 of the first 15 patients enrolled needed to achieve 6-month PFS before the next stage of full accrual was initiated. Results: 120 pts were enrolled at 11 centers; 90 of these patients had GBM at first replapse following standard chemoradiation. Patients were divided into four cohorts: GBM patients failing during the first 3–6 months of adjuvant therapy (B1); GBM patients failing after more than 6 months of therapy (B2); GBM patients who recurred after stopping treatment (B3); and anaplastic glioma patients (A). Median age for the entire sample was 52 years (range 25–73 years). The majority (66%) were male. ECOG performance status was 0 in 47% and 1 in 53%. All pts are expected to reach the primary endpoint by June 2008 and will be included in the EANO presentation. An interim analysis was performed on the first 90 patients in 02/2008. The 6-month PFS rates were 28.6% (B1), 9.5% (B2), 30.4% (B3), and 42.1% (A). Nausea and vomiting was observed in less than 5% of patients. Other toxicities were rare. Progressive lymphopenia was observed in some patients, but no clinically significant event has been observed to date. Prophylaxis for Pneumocystis carinii pneumonia was not required. Conclusions: Continuous dose-intense TMZ 50 mg/m2 administered on a 28/28 day schedule is active and well tolerated after failure of the conventional 5/28 day regimen. Efficacy compares favorably to other commonly used second-line agents. Final 6-mo PFS rates are pending, as is correlation with MGMT status. Continuous dose-intense TMZ may represent an ideal regimen for use in combination with other agents such as the new targeted therapies. O05. THERAPEUTIC EFFICACY AND TOXICITY OF LOCAL (GLIADEL WAFER) AND SYSTEMIC INTENSIFIED CHEMOTHERAPY ONE WEEK ON/ONE WEEK OFF IN RECURRENT GLIOMAS AFTER SURGICAL RESECTION C. Ewelt1, J. Schroeteler1, W. Stummer1, J. Felsberg2, H. Steiger1, M. Sabel1; 1Department of Neurosurgery, Duesseldorf, Germany, 2Department of Neuropathology, Duesseldorf, Germany Introduction: Due to the primary treatment of patients with glioblastoma multiforme (GBM) with alkylating drugs (AD) the role of a rechallenge with AD upon recurrence is subject to discussion. In addition, the impact of cytoreductive surgery for GBM, as demonstrated for the primary treatment, has not yet been evaluated for recurrent GBM. We therefore investigated the role of re-resection and intensified alkylating chemotherapy by both local and systemic regimens in a single institution series of patients with radiographic recurrence of GBM, stratified for MGMT status. Patients and Methods: Since 12/2006, 25 subsequent patients with recurrent GBM under Stupp regimen were included after informed consent was obtained. Patients were subject to re-resection and implantation of carmustin wafers and were treated with temozolomide one week on/one week off (150 mg/m2/BS), 4 weeks after surgical treatment. Patients were evaluated pre- and postoperatively by Karnofsky and NIH scores and serial MR-images (all parameters were collected presurgical, <72 h after surgery and every 3 months). Toxicity was closely monitored every week. Overall survival (OAS) and progression-free survival (PFS; McDonald criteria) were determined after 3 months (PFS-3) and 6 months (PFS-6). The MGMT promoter status was determined by methylation specific PCR. Results: All patients were resected with less than 5 ml residual tumor volume. Severe toxicity after WHO CTC was observed in 16 patients [Grade 3 (n = 10) and 4 n = 6)]. All patients demonstrated a decreased Karnofsky and NIH score immediately postoperatively, which stabilized until disease progression at a median of 70% and 7.0, respectively. As yet, the median PFS is 17 weeks, PFS-3 39%, PFS-6 0% and median OAS 18 months (first diagnosis to death). 72 % of the patients were MGMT negative. Conclusion: As yet, there are no data on the prognosis of patients with a recurrent GBM after Stupp. Therefore, the interpretation of our outcome data must be approached with caution. The high percentage of MGMT patients probably reflects a negative selection bias, due to the consecutive inclusion of recurrent patients in a single center study. However, the OAS demonstrated in our population compares favorably with the OAS of the MGMT negative subpopulation published by Hegi (20/12.7 months). Though the toxicity of this regimen is acceptable, the clinical deterioration of the patients is not only attributable to the natural course of this disease. O06. A PHASE II MULTICENTRIC TRIAL OF FOTEMUSTINE (FTM) IN PATIENTS (PTS) WITH RECURRENT/PROGRESSIVE GLIOBLASTOMA AFTER RADIOTHERAPY PLUS CONCOMITANT AND/OR ADJUVANT TEMOZOLOMIDE: A GICNO (GRUPPO ITALIANO COOPERATIVO DI NEURO-ONCOLOGIA) STUDY A. A. Brandes1, A. Tosoni1, E. Franceschi1, E. Mazza2, A. Santoro3, M. Faedi4, R. Labianca5, R. Bertorelle6, T. Perrone7, E. Pesenti7; 1Bellaria Maggiore Hospital, Bologna, Italy, 2San Raffaele Hospital, Milano, Italy, 3Istituto Clinico Humanitas, Rozzano, Italy, 4Ospedale Bufalini, Cesena, Italy, 5Ospedali Riuniti, Bergamo, Italy, 6Istituto Oncologico Veneto, Padova, Italy, 7Italfarmaco, Milano, Italy Background: No drug has yet been proven effective in patients with GBM at time of failure after standard radiotherapy plus concomitant and adjuvant temozolomide. Although nitrosoureas may be considered as the gold standard, no data are available in an homogeneously pretreated population. Methods: Pts with recurrent/progressive GBM after ⩾3 mo from the end of radiochemotherapy received 3 weekly doses of FTM (75 mg/m2 i.v.) followed, after a 5-week rest, by FTM (100 mg/m2 i.v.) every 3 weeks for < 1 year; treatment was suspended if disease progression or unacceptable toxicity was observed. The main endpoint was to ascertain progression-free survival at 6 months (PFS-6). According to Fleming's design, a sample size of 40 patients was planned assuming P0=0.10, P1=0.25, α=0.1, β=0.1 Results: Between April 2005 and May 2006, 6 Italian GICNO network centers enrolled 43 pts (29 M, 14 F; median age, 52 [range 34–68] years; median KPS 90, range 70–100). PFS-6 was 21% (SE 6.2%); 3 patients (7%) had partial response (PR), and 15 (35%) disease stabilization (SD). Two out of 3 responsive pts are alive after 21 and 22.7 months, and 1 died after 15.5 months. Median survival time was 6 months (95% CI: 5–7). MGMT methylation status was determined in 34 pts (73.5%): 8 (23.5%) were methylated and 26 (76.5%) unmethylated. In methylated pts, disease control was significantly better than in unmethylated pts (75% vs. 34.6%, p=0.05); however no significant difference in terms of PFS-6 and survival was observed. Grade 3–4 thrombocytopenia and neutropenia were observed in 25.6% and 30.2% of pts, respectively. Conclusions: The findings of this present trial, the first to analyze second-line nitrosourea treatment in a homogeneous population following standard treatment, may represent a new benchmark of nitrosourea activity. However, as disease control was not long-standing, alternative doses, schedules, and drug-combinations should be evaluated in future studies. (This trial has been supported by an unrestricted grant of Italfarmaco Pharmaceuticals, Milan, Italy.) O07. MULTIMODAL PREOPERATIVE MR-IMAGING IN PATIENTS WITH PRESUMED LOW-GRADE GLIOMAS IN ELOQUENT LANGUAGE AREAS —IMPLICATIONS FOR TARGETED SURGICAL RESECTION R. Gerlach, E. Hattingen, K. Franz, T. Gasser, I. Kropf, A. Szelenyi, V. Seifert; Johann Wolfgang Goethe University, Frankfurt, Germany Objectives: To analyze the value of preoperative multimodal MR-imaging (1H MR-spectroscopy [1H MRS], fMRI, CBF) in patients with dominant hemisphere gliomas in close relation to language areas with respect to surgical treatment strategy. Methods: Data derived from a prospective series of 19 consecutive patients with newly diagnosed gliomas in the dominant hemisphere in close relation to anatomical language areas treated between November 2005 and November 2007. Mean patients' age was 45 ± 12 years, and 12 patients were male (63%). All patients underwent awake craniotomy for intraoperative language testing (counting, naming, action naming) and at least partial tumor resection according to intraoperative stimulation results. Data of multimodal preoperative imaging were implemented in surgical navigation (Brain Lab, Germany). Signs of focal tumor dedifferentiation were considered in cases of partial contrast enhancement in standard MRI, increased choline in 1H MRS, and increased regional cerebral blood flow (rCBF) in perfusion weighted MRI. In patients with extended tumors with limited surgical treatment option the intended surgical goal was to remove the suspected dedifferentiated tumor part defined by preoperative multimodal MR imaging. Results: According to standard preoperative MRI, 8 patients had signs suspicious of focal malignant tumor dedifferentiation. In addition, 9 patients' 1H MRS and rCBF measurements indicated focal malignant transformation. Although complete surgical resection of the tumors was deemed impossible due to intraoperative language test results, the dedifferentiated tumor part could be completely removed in all patients as proven by postoperative MRI. A temporary decrease in language function was seen in 16 patients (84%) but resolved within 1 week in 14 of them. In 13 of the patients with targeted resection, histology proved malignant transformation and therefore these patients underwent adjuvant treatment. Conclusions: Multimodal preoperative MR imaging is helpful to detect focal malignant transformation missed in standard diagnostic MRI in patients with presumed low-grade gliomas. In patients in which complete resection is precluded due to infiltration of functional language areas a targeted resection of the dedifferentiated tumor part(s) is a prerequisite for adequate histological diagnosis. However, long-term follow-up assessment is necessary to show, whether or not targeted resection of malignant tumor parts and adjuvant treatment prolongs survival in these patients. O08. COMBINED USE OF DTI FT AND INTRAOPERATIVE SUBCORTICAL MAPPING FOR SURGICAL REMOVAL OF GLIOMAS L. Bello1, A. Castellano2, G. Bertani1, A. Gambini2, A. Casarotti1, A. Falini2; 1Neurosurgery, University of Milano, Milano, Italy, 2Neuroradiology, University Vita e Salute, Milano, Italy Objective: to determine the uselfulness of the combined use of motor and language tract DTI FT and intraoperative subcortical mapping for surgical removal of gliomas. Methods: 110 patients with gliomas (90 low and 20 high grade) were submitted to surgery with the aid of motor and language mapping (ISM). DTI-FT data for CST, IFO, SLF, and UNC were available at the time surgery. DTI-FT was acquired by a 3-T MR scanner with a single-shot EPI sequence (TR/TE 8986/80 msec, b=1000 s/mm) with gradients applied along 32 non-collinear directions. Data were transferred to the neuronavigational system. Functional subcortical sites identified during subcortical mapping were correlated with fiber tracts depicted by DTI-FT. The impact of the combined use of DTI FT and subcortical mapping on duration and modalities of surgical procedures and on functional outcome of the patients was also evaluated. Results: In high-grade gliomas DTI-FT depicted tracts mostly at the tumor periphery; in low-grade gliomas fibers were frequently located inside the tumor mass. There was a high correlation between DTI-FT and ISM (sensitivity for CST=95%, language tracts=97%). For a proper reconstruction of the tracts, it was necessary to use a low FA threshold of fiber tracking algorithm and to position additional regions of interest (ROIs). The combination of DTI-FT and ISM decreased the duration of surgery, patient fatigue, and intraoperative seizures. Conclusions: Our data indicate a good concordance between DTI-FT data and those obtained during subcortical mapping. When used in combination with subcortical mapping, DTI-FT offers the opportunity to quickly find the fibers associated with motor or language functions during surgery. The clinical relevance of this combined approach comes from the fact that it further enhances surgical safety maintaining a high rate of functional preservation. O09. SURGERY OF INSULAR WHO GRADE II GLIOMAS: A CONSECUTIVE SERIES OF 52 PATIENTS H. Duffau; Hôpital Gui de Chauliac, Montpellier, France Rationale: For a long time, insular gliomas have been considered inoperable. Thus, few experiences of insular surgery have been reported, especially concerning WHO grade II glioma (GIIG). Here, the author details a 10 years personal consecutive experience of 52 patients operated on for a GIIG involving the insular lobe. On the basis of the functional and oncological results, both advances and limitations of this challenging surgery are discussed. Patients and Methods: Between 1997 and 2007, 52 patients (31 men and 21 women, median age 36 years) with an insular GIIG underwent surgery. The tumor was revealed by seizures in 51 cases; 18 patients had chronic epilepsy (34%). The preoperative examination was normal in 46 patients (88%). Five patients presented with mild language disorders, and one patient with a left hemiparesis. All surgeries were conducted under cortico-subcortical stimulation and in 16 patients while awake. In all cases, the resection was stopped according to functional boundaries. Results: There was neither operative nor postoperative mortality. Despite a transient worsening in 30 cases (58%), all patients but two (96%) returned to baseline or better. Furthermore, 14 of the 18 patients (78%) who presented with preoperative chronic epilepsy had a relief of seizures. On control MRI, 77% of resections were total or subtotal. Pathological examination revealed a WHO grade II glioma in all cases. Ten patients underwent a second or third surgery, with no additional deficit. The tumor was still a GIIG in 7 patients, whereas anaplastic transformation was diagnosed in 3 cases. A complementary treatment was given in 20 patients (chemotherapy alone in 9 cases; chemotherapy and radiotherapy in 11 cases). Forty-three patients (82%) are still alive with a median follow-up of 48 months (from 3 to 121 months). Conclusions: This is the largest ever reported experience with insular GIIG surgery. The better knowledge of the insular pathophysiology and the use of intraoperative functional mapping enable minimizing the risk of permanent deficit (and even improving the quality of life) while increasing the extent of resection and thus the impact on the natural history. Therefore, surgical removal has to systematically be considered for insular GIIG. However, this surgery remains challenging, especially within the anterior perforating substance and the posterior part of the (dominant) insula. Repeated operations can be suggested when the first resection was not complete. O10. THE IMPACT OF RESECTION IN THE TREATMENT OF GLIOBLASTOMA MULTIFORME: SURVIVAL COMPARISON WITH THE RTOG RECURSIVE PARTITIONING ANALYSIS OF ALA GLIOMA STUDY PATIENTS W. Stummer1, U. Pichlmeier2, G. Schackert3; 1Department of Neurosurgery, Düsseldorf, Germany, 2Medac GmbH, Hamburg, Germany, 3Department of Neurosurgery, Universitätsklinikum Dresden, Germany Purpose: The benefit of cytoreductive surgery for glioblastoma multiforme (GBM) has not been demonstrated conclusively and selection bias in past series has been observed. The ALA study investigated the influence of fluorescence-guided resections on outcome, generating an extensive database on GBM patients with a high frequency of complete resections. With the present analysis we evaluated whether the RTOG recursive partitioning analysis (RPA) would predict survival of ALA study patients and whether there was any detectable benefit from extensive resections depending on RPA class. Patients and Methods: 243 per protocol patients with newly diagnosed GBM were operated either with or without ALA and treated by radiotherapy. Early postoperative MRI was obtained in all patients. Patients were allocated into RTOG-RPA classes III, IV, and VI based on age, Karnofsky Performance Status, neurological condition, and mental status (as derived from the National Institute of Health stroke score). Results: Overall survival was different among RPA classes III, IV, and V, with median survival times of 17.8, 14.7, and 10.7 months, respectively, and 2-year survival rates of 26%, 12%, and 7%, respectively (p=0.0007). When stratified for complete vs. incomplete resections of contrast-enhancing tumor, survival for patients with complete resections was longer in RPA classes IV and V (17.7 vs. 12.9, p=0.0015, and 13.7 vs. 10.4, p=0.0398; 2-year rates: 21.0 vs. 4.4% and 11.1 vs. 2.6%, respectively). In the small subgroup of RPA class III patients, differences were 19.3 vs 16.3 months (p=0.14). Conclusion: Survival of patients from the ALA study is correctly predicted by the RTOG-RPA classes. Differences in survival depending on resection status, especially in RPA classes IV and V, strongly support a causal influence of resection on survival. O11. COMBINED USE OF TRACTOGRAPHY-INTEGRATED FUNCTIONAL NEURONAVIGATION AND 5-ALA FLUORESCENCE NAVIGATION DURING RESECTION OF GLIOBLASTOMA MULTIFORME INVOLVING PYRAMIDAL TRACT K. Sato, T. Ito, M. Oikawa, H. Nakamura; Nakamura Memorial Hospital, Sappporo, Japan Objective: For the patients with glioblastoma multiforme (GBM) involving pyramidal tracts, maximal resections are difficult to accomplish preserving their motor function. We use tractography-integrated functional neuronavigation and 5-aminolevulinic acid (5-ALA) fluorescence-guided resection following the removal of GBM involving pyramidal tracts. In this study we analyze the postoperative motor function and extent of resection in a series of patients who underwent surgery in our department. Materials and Methods: Eight patients with GBM involving pyramidal tracts received radical surgery. To preserve pyramidal tracts, we have used the tractography-integrated functional neuronavigation since 2006. We also developed a functional neuronavigation-guided fence-post procedure in 2007 to resolve the problem of brain shift, a disadvantage of the existing neuronavigation system. And we have attained precise resection on the tumor using 5-ALA fluorescence navigation. Intraoperatively, tumor fluoresence was visualized using a modified operating microscope. All fluorescing tumor tissue was resected. Results: Motor function was preserved after appropriated tumor resection in all cases. Postoperatively, improvement of motor weakness was observed in six patients, whereas transient mild motor weakness occurred in two patients. Gross total removal was accomplished for four patients, subtotal removal was accomplished for two patients, and partial removal was accomplished for two patients. Conclusions: Combined use of tractography-integrated functional neuronavigation and 5-ALA fluorescence-guided resection contributes to maximal safe resection of GBM with pyramidal tract involvement. O12. SURGERY GUIDED BY 5ALA FLUORESCENCE IS A SAFE AND EFFICIENT METHOD WITH THE POTENTIAL TO GREATLY INCREASE THE RATE OF GROSS TOTAL RESECTION IN GLIOBLASTOMA R. Diez Valle, S. Tejada Solis, M. Idoate Gastearena; Clinica Universitaria de Navarra, Pamplona, Spain Background: Gross total resection is increasingly recognized as an important first step and prognostic factor in the treatment of glioblastoma. In spite of this, most published papers lack an objective measurement of residual tumor after surgery. The removal of the entire MRI enhancing lesion is accepted as the gold standard of gross total resection. When this measurement of residual tumor by post-op MRI is done, the frequency of verified total resection is quite low, between 18%–49%. Fluorescence guided resection of glioblastoma using 5 aminolevulinic acid (5-ala) is a new technique developed by Dr. Stummer. The European Medical Agency approved the marketing of 5-ala for this indication under the name Gliolan in January 2008. In an unusual agreement, the agency approved it to be used only by neurosurgeons who have done a specific training course. Methods: We report our initial experience with 10 glioblastoma cases. The cases were consecutive patients in which surgery was indicated. There were three recurrent cases. We did volumetric MRI measurement pre- and postoperatively. For each case we took 6–8 biopsies of the borders of the lesion and the normal tissue, as shown by the fluorescence. Results: In all our cases, we could see under the fluorescence three different zones: pure tumor tissue in bright red; infiltrating tumor cells in the border of the lesion with the color gradually less intense, becoming shades of pink; and normal tissue in blue. The correlation with the histology was excellent, with 100% specificity in non-recurrent cases, 80% in recurrences, and 94% sensibility. Interestingly, the pink areas always corresponded with tumor cells infiltrating brain tissue, never with solid tumor. We achieved 100% resection as measured by MRI in 7 cases, while the mean volume resected over the 10 cases was 98.9%. Mean preoperative volume was 52 cc. There was no new neurological morbidity in the series. Conclusions: The fluorescence produced by 5-ala is a very efficient and safe method of achieving maximal safe resection of glioblastoma. This method allows the surgeon to see the solid tumor as well as the infiltrating border, which has a high tumor cell density. It could achieve greater resection than MRI guided surgery. With this technique it's possible to obtain separate samples of the infiltrating border of the tumor during the surgery, and we think this could be useful for specific research on the diffuse part of the tumor. O13. CPG-OLIGONUCLEOTIDES ARE SUPERIOR TO OTHER TLR LIGANDS IN THE LOCAL TREATMENT OF ESTABLISHED INTRACEREBRAL MURINE GLIOMAS O. M. Grauer1, J. W. Molling2, R. P. M. Sutmuller3, S. Nierkens2, G. J. Adema2; 1Department of Neurology, University of Regensburg, Regensburg, Germany, 2Department of Tumorimmunology, NCMLS, Radboud University of Nijmegen, Nijmegen, The Netherlands, 3Organon NV, Target Discovery, Oss, The Netherlands Introduction: Gliomas are aggressive brain tumors that actively suppress anti-tumor immune responses. A key event for glioma immune escape is the intratumoral accumulation of CD4+FoxP3+ regulatory T cells, which actively suppress local CD4 and CD8 effector T cell responses. In mice, we attempted to restore local T cell responses by intratumoral injection of various toll-like receptor (TLR) ligands. Methods: Mice bearing intracerebral GL261 gliomas received a single intratumoral injection of various TLR ligands five days after tumor challenge and were monitored for survival. T cells were isolated at different time points from the tumor and cervical lymph nodes or spleen for functional characterization. In addition, direct effects of various TLR ligands on GL261 glioma cells were determined in vitro. Results: A single intratumoral injection of CpG-oligonucleotides (CpG-ODN, TLR9) most effectively inhibited glioma growth in vivo and cured 80% of glioma-bearing mice. Intratumoral injection of Pam3Cys-SK4 (TLR1/2) or R848 (TLR7) also produced a significant survival benefit, whereas Poly I:C (TLR3) or purified LPS (TLR4) stimulation alone was not effective. Applying CpG-ODN, potent CD4 and CD8 T-cell responses were induced that protected cured mice from a subsequent tumor challenge without further addition of CpG-ODN. In addition, the entry of CD4+Foxp3+ regulatory T cells into the tumor was strongly counteracted by IFN-γ secreting CD4+ and CD8+ effector T cells upon CPG-ODN treatment. In vitro, CpG-ODN appeared to inhibit GL261 glioma cell proliferation in a cell-type specific, but CpG-motif independent manner. Studies using TLR9+/+ wildtype and TLR9-/- knockout mice revealed that the efficacy of local CpG-ODN treatment in vivo is mainly immune-mediated. Conclusion: In summary, this study underlines the potency of local TLR treatment in anti-glioma therapy and demonstrates that local CpG-ODN treatment most effectively restores anti-tumor immunity in a therapeutic murine glioma model. O14. INHIBITION OF DIFFUSELY INVASIVE GLIOBLASTOMA GROWTH IN VIVO BY TARGETING EGFR BUT NOT VEGFR-2 K. Lamszus1, T. Martens1, Y. Laabs1, H. Günther1, L. Witte2, M. Westphal1; 1Dept. of Neurosurgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany, 2ImClone Systems, New York, NY, United States Objective: A major shortcoming of traditional mouse models based on xenografted human glioblastoma cell lines is that tumor cells do not invade. Another deficit is that genetic alterations, such as amplification of the epidermal growth factor receptor (EGFR), are typically not maintained in glioma cell lines and xenografts derived thereof. These models are therefore of limited value for preclinical therapeutic studies. We established a highly invasive orthotopic nude mouse model to evaluate the effects of monoclonal antibodies against EGFR (cetuximab) and vascular endothelial growth factor receptor-2 (VEGFR-2, antibody DC101). Methods: Freshly resected glioblastoma tissue was minced and briefly cultured as spheroids in vitro. Spheroids were stereotactically injected into the striatum of nude mice. Animals were treated for 4 weeks with either interstitial infusion of cetuximab or intraperitoneal injections of DC101. Tumor extension was measured using image analysis on H&E-stained serial sections, defining 36 landmark points at 6 different coronal levels with 6 different areas each (e.g., striatum, corpus callosum, thalamus). Results: Highly invasive xenografts were obtained from 9 different glioblastomas. Of 7 different xenograft-cases treated with cetuximab, 3 responded to treatment with significant tumor growth inhibition, whereas 4 did not. All responsive tumors were derived from glioblastomas exhibiting EGFR gene amplification as well as expression of the truncated EGFRvIII variant. EGFR amplification was maintained in mouse xenografts as determined by FISH analysis. The proportion of apoptotic cells was increased in responding tumors, whereas the fraction of proliferating cells was decreased. All non-responsive tumors lacked EGFR amplification and EGFRvIII expression. None of 4 xenograft cases treated with DC101 responded to treatment, and quantification of intratumoral blood vessels showed that the diffusely invading tumors grew largely independent of angiogenesis. Conclusions: This is the first study showing that inhibition of invasive glioblastoma growth can be achieved in vivo using interstitial delivery of an anti-EGFR antibody. Importantly, tumor responsiveness depended on the presence of amplified and/or mutated EGFR. In contrast, anti-angiogenic treatment was not effective against the diffusely invading tumors. O15. DIFFERENTIATION THERAPY EXERTS ANTI-TUMORIGENIC, ANTI-ANGIOGENIC, ANTI-INVASIVE AND PROAPOPTOTIC EFFECTS IN BRAIN TUMOR STEM CELL–DERIVED TUMORS B. Campos1, F. Wan1, F. Zeppernick1, R. Ahmadi1, M. Farhadi1, W. Roth2, P. Beckhove3, A. Unterberg1, B. Radlwimmer4, C. Herold-Mende1; 1Division of Neurosurgical Research, Department of Neurosurgery, University of Heidelberg, Heidelberg, Germany, 2Molecular Neuro-Oncology, German Cancer Research Center, Heidelberg, Germany, 3Division of Tumor Immunology, German Cancer Research Center, Heidelberg, Germany, 4Division of Molecular Genetics, German Cancer Research Center, Heidelberg, Germany Background: Tumor stem cells (TSCs) are responsible for tumor initiation and therapy resistance in a variety of cancers, including leukemia, carcinomas of the breast and colon as well as several types of brain tumors. Differentiation of TSCs has been discussed as a possible approach to eradicate the tumor-driving cell population disrooting the actively proliferating tumor bulk. Since all-trans retinoic acid (ATRA) is known as a modulator of differentiation and proliferation, we sought to elucidate whether ATRA induces differentiation of glioblastoma-derived TSCs, so-called brain tumor stem cells (BTSCs), and if tumor-relevant properties of these cells are affected by differentiation. Methods: BTSC lines (n=3) with high CD133 content (68%–93%) were treated with ATRA-containing medium. Change in proliferation and CD133 content was monitored by BrDU incorporation assay and FACS analysis, respectively. Impact of differentiation on the angiogenic capacity of BTSCs was measured by quantification of angiogenic cytokines and assessed in a HUVEC-based tube formation assay. Potential effects on BTSC invasiveness were studied in a 3D-collagen invasion model. Finally, we studied whether in vitro effects could be confirmed in vivo using a NOD/SCID-mouse xenograft model. Results: We present evidence that BTSCs exposed to ATRA increase their proliferative activity and simultaneously lower the expression of stem cell–related antigen CD133 by up to 75% in favor of incremented linage markers GFAP, MBP, and beta3-tubulin. Furthermore, we report on significantly reduced VEGF and bFGF secretion by 70%–82% and 95%–99%, respectively, as well as significantly lowered tube formation by up to 55% following differentiation. Additionally, we show that differentiation elicits strong anti-invasive effects reducing collagen invasion by up to 46% and that these effects are associated with a marked downregulation of invasion-related MMP2 protein (up to sevenfold). Finally, we report that xenografted tumors of differentiated BTSCs are significantly smaller (only 15% of BTSC tumor volume) and less invasive than undifferentiated BTSC tumor xenografts. Correspondingly, animals bearing differentiated cells show both significantly better PFS and OS than mice with BTSC xenografts (p<0.016). Conclusion: Altogether, these results highlight the potential of differentiation treatment to target the tumor-driving compartment in glioblastoma and point out a potential therapeutic value in the eradication of TSCs. O16. ANTIANGIOGENIC TREATMENT REDUCES TUMOR VASCULATURE AND TUMOR CELL INFILTRATION IN A GLIOMA CANCER STEM CELL MODEL IN NUDE MICE L. Bello1, C. Verpelli1, G. Bertani1, G. Casaceli1, V. Lucini2, R. Galli3, C. Sala4; 1Neurosurgery, University of Milano, ELAT, Milano, Italy, 2Pharmacology, University of Milano, ELAT, Milano, Italy, 3Stem Cell Research Institute, DIBIT, HSR, Milano, Italy, 4Pharmacology, University of Milano, CNR, ELAT, Milano, Italy Angiogenesis and invasion are strictly related phenomena involved in glioma genesis and progression. In vivo models based on the intracerebral injection of glioma cancer stem cells are well suited for studying the relationship between these two phenomena, because they both possess in these tumors features similar to those observed in the human setting. In the first part of this work we analyzed the changes in tumor vasculature and cell infiltration during the various phases of tumor progression in a glioma nude mice model generated by the injection of glioma cancer stem cells isolated by a case of human anaplastic astrocytoma. Animals were sacrificed at various time points after glioma cancer stem cell injection. Sections were evaluated for vascular parameters (vessel number, diameter, length, basal membrane, pericytic coverage, tumor hypoxia) and pattern of tumor cell infiltration. At early stage a small tumor mass, consisting of an agglomerate of dispersed elongated tumor cells, diffusely infiltrating the surrounding brain parenchyma, was evident. Most of the cells were co-opting preexisting tumor vasculature; in the tumor mass actively growing capillaries were present. At intermediate stage, larger tumors composed of a tumor core surrounded by a large area of infiltration were documented, in the context of which several foci of anaplasia were evident. Angiogenesis was active, both in the tumor mass and particularly in the foci. At late stage, the tumors were large, densily and extensively infiltrating the brain parenchyma. Necrosis was also present. Angiogenesis was active and heterogeneous, with glomeruloid structures, mature and actively growing capillaries, co-opting vessels. This model strictly resembles human glioma, in terms of tumor cell and vasculature heterogeneity and tumor cell infiltration. It represents a good model of progression, which occurs at both the tumor cell and vasculature levels. Angiogenesis is striclty associated with invasion. In the second part of the work, we investigated if angiogenic treatment was able to inhibit the progression of the tumor toward more aggressive phenotype. Angiogenic inhibitors were administered alone or in combination to animals with early or intermediate stage tumors. Mice were sacrificed at various time points, and the infiltrative and angiogenic pattern of the tumors evaluated as previously described. In both settings, antiangiogenic treament reduced angiogenesis and tumor cell infiltration. The effect was more prominent at early stage, where tumor progression was also inhibited. O17. TUMOR SPECIFIC MIGRATION OF BONE-MARROW DERIVED RAT MESENCHYMAL STEM CELLS IN THE INVASIVE N29 RAT BRAIN TUMOR MODEL D. Bexell1,2, S. Gunnarsson1,2, A. Tormin2, D. Gisselsson3, S. Scheding2, J. Bengzon1,2; 1Clinical Sciences, Neurosurgery, Lund University, Lund, Sweden, 2Lund Strategic Research Center for Stem Cell Biology and Cell Therapy, Lund University, Lund, Sweden, 3Clinical Genetics, Lund University, Lund, Sweden Bone-marrow derived mesenchymal stem cells (MSCs) have emerged as a promising cellular vehicle for delivery of anti-tumoral substances in glioma therapy. However, the capacity of MSCs to specifically migrate within an invasive GBM-like model has not been quantatively analyzed. Here we quantified the extent to which MSCs migrate to invasive tumor extensions and to distantly located tumor micro satellites. For this purpose, we isolated MSCs from the bone-marrow of adult Fischer344 rats, retrovirally labeled MSCs to express GFP, and grafted GFP+ MSCs into the highly invasive N29 rat brain tumor in adult Fischer344 rats. MSC grafting was done intratumorally into established tumors in order to resemble a clinical scenario where MSCs are grafted following partial tumor resection. We counted the numbers of tumor extensions and distantly located tumor micro satellites that were infiltrated by GFP+ MSCs at three time-points following grafting. The percentage of tumor extensions infiltrated by MSCs, 5, 10, and 15 days after MSC grafting, was 59±14 %, 76±3 % and 70±11 %, respectively, and the percentage of distantly located tumor micro satellites infiltrated by MSCs were 20±7 %, 26±4%, 34±6%, respectively. Importantly, MSC migration was largely restricted to tumor tissue and minimal numbers of MSCs were found in the normal brain parenchyma. These findings were confirmed by FISH analysis of male MSCs grafted into female hosts. Thus, we demonstrate proof-of-principle that one single MSC injection results in infiltration of the majority of invasive tumor extensions and of a significant fraction of tumor microsatellites. Multiple intratumoral injections at different coordinates will likely increase the numbers of tumor satellites infiltrated by grafted MSCs. O18. IN VITRO INVESTIGATION OF VARIZELLA ZOSTER VIRUS AS AN ONCOLYTIC VIRUS IN GLIOBLASTOMA THERAPY N. Thon1, H. Leske1, C. Schichor1, J. Tonn1, R. Goldbrunner1, A. Baiker2; 1Department of Neurosurgery, Munich, Germany, 2Max von Pettenkofer Institute, Munich, Germany Introduction: Varizella Zoster Virus (VZV) is an oncolytic virus solely replicating by cell-cell fusion processes. Recently, it has been shown that VZV is suitable for tumor therapy in malignant melanomas. Focusing on a future oncolytic therapy for malignant gliomas, the aim of the following study was to asses permissive VZV replication in glioma cell lines and primary glioblastoma cell cultures in vitro. Methods: Three gliomas cell lines (U87, U252, U373) and six primary cell cultures from human glioblastoma specimens have been tested for permissive cellular VZV replication in vitro. An established melanoma in vitro model has been used as positive control, and three normal brain cell cultures (NBC) have been used as negative controls. Since bone marrow derived human mesenchymal stem cells (hMSC) are regarded as potential carriers of oncolytic therapy, three hMSC cultures were included in this study. Infection rates have been qualitatively and quantitatively evaluated by cellular expression of early (e.g., ORF63) and late (e.g., ORF68) viral proteins using immunocytochemistry. Oncolytic potency has been evaluated by cell counting and comparative morphometric culture analysis in simultaneously VZV infected glioma cells, hMSCs and normal brain derived cells in a time dependent protocol. Results: Except for U87 cell line, permissive VZV replication has been verified in all glioma cell cultures tested including all primary cultures (8/9). Efficient total oncolytic cell death was detected within 6±3 days after VZV infection. Interestingly, plaque formation and syncytial fusion, which are characteristic for melanoma VZV replication, rarely occurred within glioma cell lines. Cell cultures harvested from normal brain specimens also exhibited ORF63/ORF68 expression but showed delayed single cell death (16±4 days after VZV infection). Interestingly, besides established VZV infected melanoma cells, permissive VZV replicating hMSCs have also been highly suitable for cellular vehicles in glioma cell infection. Conclusion: Wild-type VZV efficiently replicates within glioma cell cultures causing broad oncolytic cell death in vitro. The underlying mechanisms causing infections devoid of characteristic plaque formation are still unknown. Since hMSCs are known to have an intrinsic tumor cell tropism, autologous VZV-replicating hMSCs could be applicable as cellular vehicles for local oncolytic glioma cell infection. Further investigations have to address sufficient glioma cell selectivity in VZV replication with respect to the normal brain parenchyma. O19. A MULTICENTER STRATIFIED PHASE II STUDY OF CETUXIMAB FOR THE TREATMENT OF PATIENTS WITH RECURRENT HIGH-GRADE GLIOMA B. Neyns1, J. Sadones1, E. Joosens2, F. Bouttens3, L. Verbeke4, J. Baurain5, L. Dhondt6, T. Strauven7, C. Chaskis1, A. Michotte1; 1UZ Brussel, Brussel, Belgium, 2Middelheim ZNA, Antwerpen, Belgium, 3AZ St. Lucas, Gent, Belgium, 4OLV Aalst, Aalst, Belgium, 5Cliniques Universitaires St. Luc, Bruxelles, Belgium, 6Centre Hospitalier Notre-Dame et Reine Fabiola, Charleroi, Belgium, 7AZ St. Augustinus, Antwerpen, Belgium Background: An increased copy number and mutation of the epidermal growth factor receptor (EGFR) gene are frequently found in high-grade gliomas (HGG). We investigated the activity of the EGFR-blocking monoclonal antibody cetuximab (Erbitux) for the treatment of patients (pts) with recurrent HGG following surgery, RT, and chemotherapy. Methods: Eligible adult pts were treated with cetuximab (400 mg/m2 2 h i.v. on d1 and weekly 250 mg/m2 1 h i.v. thereafter). Pts were stratified in 2 treatment arms according to the amplification status of the EGFR gene of their high-grade glioma (determined by fluorescence in situ hybridization on archival tumor material). Results: Between May 2005 and December 2007 a total of 55 pts with performance status 0–2 initiated treatment with cetuximab (28 pts with and 27 pts without an increased EGFR copy number, 17F/38M, median age 53 years [range 32–73]). Cetuximab was generally well tolerated. During a total of 765 treatment weeks the most frequent treatment-related adverse events were: skin toxicity (grade 2, n=12; grade 3, n=5), thrombocytopenia (grade 2, n=1; grade 3, n=2), confusion/diminished consciousness (grade 3, n=4 pt), lymphopenia (grade 4, n=1), infusion related allergic reaction (grade 2, n=1), intratumoral hemorrhage (grade 2, n=1), diarrhea (grade 2, n=1), and fatigue (grade 2; n=3). A dose reduction of cetuximab (to 200 mg/m2 weekly) was necessary in 3 pts. After a median follow-up of 17 months, 8 pts are alive (4 are still receiving cetuximab) and 47 pts have died. The disease control rate (DCR) was 36% (3 pts [5.5%] had a PR and 16 pts [29.1%] had SD); 36 pts (65.4%) had PD. The median PFS was 1.9 months (95% CI 1.6–2.2); median OS was 5.0 months (95% CI 4.4–5.7). The 6-month PFS and OS rates were 8.7 % and 35%, respectively. No significant correlation was found between EGFR amplification and DCR or survival. Whereas PFS was <5 months in 49/54 of pts (91%) with a follow-up of >5 months, a subgroup of 5 pts (9%) have a PFS of >9 months (range 9.5 to >18.5). This subgroup consisted of 4 pts with de novo glioblastoma (3 without and 1 with EGFR amplification) and 1 pt with an anaplastic astrocytoma with EGFR amplification. Conclusions: Cetuximab as a single agent was safe and well tolerated in this population of pretreated patients with recurrent HGG. Durable disease control was observed in a small subgroup of patients but was not predicted by EGFR amplification at initial diagnosis. O20. PHASE II STUDY OF ANTINEOPLASTONS A10 AND AS2-1 INFUSIONS (ANP) IN PATIENTS WITH RECURRENT ANAPLASTIC ASTROCYTOMA S. R. Burzynski, R. Weaver, T. Janicki, B. Szymkowski, M. Walczak, G. Burzynski; Burzynski Clinic, Houston, TX, United States Anaplastic astrocytomas (AA) (WHO grade III) constitute less than 10% of all gliomas. The prognosis for patients with these tumors is poor; even with the most aggressive therapies, including surgery and adjuvant radiation therapy and chemotherapy, the 5-year survival for newly diagnosed patients is currently less than 30%. For recurrent AA the overall survival is less than 2 years. The purpose of this study is to evaluate the outcome of adults with recurrent AA treated with ANP in an FDA-monitored phase II clinical trial. ANP affects multiple targets, and its components have different mechanisms of action. A10 interferes with signaling in the AKT2 and MYCC pathways, blocks expression of TGFB1, activates the PTEN and MAD tumor suppressor genes, and normalizes nuclear transport by decreasing the expression of RANBP1, which may restore the activity of the mutated INI protein. AS2-1 interferes with signal transmission in the RAS and BCL2 pathways and activates expression of the tumor suppressors TP53 and p21. Twenty assessable adults, all diagnosed with AA, whose ages ranged from 20 to 51 years (median age 41 years), were involved in this study. The tumor recurred in all patients after radiation therapy, and 55% of patients received additional chemotherapy before the recurrence. ANP was administered intravenously daily through a subclavian venous catheter via a double-channel infusion pump. The median duration of treatment was 6.5 months and the median of average dosages of A10 was 5.8 g/kg/day and of AS2-1 was 0.24 g/kg/day. The treatment was well tolerated with only one case of a serious toxicity of hypernatremia. Complete response (CR) was achieved in 15%, partial response (PR) in 10%, stable disease (SD) in 45%, and progressive disease in 30% of patients. Overall survival (OS) at 2 years was 35%. The median of progression-free survival based on K-M was 10.3 months. These results compare favorably with the outcome of standard treatment. In conclusion, ANP is well tolerated and provides encouraging results in the treatment of recurrent AA and merits further investigation in a randomized phase III trial in comparison to standard treatment. O21. A RANDOMIZED TRIAL OF PROCARBAZINE, CCNU AND VINCRISTINE (PCV) VS. TEMOZOLOMIDE (5-DAY OR 21-DAY SCHEDULE) FOR RECURRENT HIGH-GRADE GLIOMA (MEDICAL RESEARCH COUNCIL TRIAL BR12, ISRCTN83176944) M. Brada, for the BR12 collaborators; Institute of Cancer Research, Sutton, United Kingdom Background: Nitrosourea-based chemotherapy (NBC) is a widely used treatment for patients (pts) with recurrent high-grade glioma (HGG) who have not received prior chemotherapy. Although temozolomide (TMZ) is increasingly used, it has never been directly compared with NBC. We report results of a Cancer Research UK–funded randomized trial of PCV vs. TMZ and comparison of two dosing schedules of TMZ at first recurrence of HGG. Methods: Chemo-naïve pts with radiologically confirmed, recurrent HGG, considered fit for chemotherapy were randomized through the MRC Clinical Trials Unit in the ratio 2:1:1 to PCV, TMZ-5, and TMZ-21. The TMZ schedules were 200mg/m2 for 5 days (TMZ-5) or 100 mg/m2 for 21 days (TMZ-21), both schedules repeated every 28 days for up to 9 cycles or until progression. PCV comprised procarbazine 100 mg/m2 p.o. days 1–10, CCNU 100 mg/m2 p.o. day 1, and vincristine 1.5 mg/m2 (max 2 mg) i.v. day 1; cycles repeated every 6 weeks for up to 6 cycles or until progression. The primary (1°) comparison is PCV vs. TMZ (either schedule); the 1° outcome is survival, and the trial is powered to detect a 2–3 month increase in median survival with TMZ corresponding to hazard ratios (HR) of 0.75 and 0.67, respectively. We require 380 deaths to detect HRs of 0.67 with 95% power and 0.75 with 80% power, α=0.05 (2-sided). To observe 380 deaths, a maximum of 500 pts randomized over 4 years was anticipated, with a planned subgroup analysis in 300 glioblastoma multiforme (GBM) pts. Progression-free survival (PFS) at 3 months is the 1° outcome for the comparison of the two TMZ schedules. 220–250 pts randomized with respect to dose would provide 80% power to detect absolute differences of 15%–20% in PFS rates at 12 weeks. Results: Accrual began in July 2003 and closed on January 31, 2008. 447 pts were randomized. Approximately 75% of pts have GBM tumors. We anticipate 380 deaths by July 2008, when the majority of patients will have completed treatment, and we will conduct the primary analysis at this time. The data to be presented will therefore include treatment compliance and toxicity data, the intent-to-treat logrank analysis of survival for the TMZ and PCV arms in the whole trial population and the GBM subgroup and the PFS logrank analysis for the PCV vs. TMZ comparison, and for the two TMZ schedules individually. O22. ENZASTAURIN (ENZ) VERSUS LOMUSTINE (CCNU) IN THE TREATMENT OF RECURRENT, INTRACRANIAL GLIOBLASTOMA (GBM): A PHASE III STUDY W. Wick1, V. K. Puduvalli2, M. Chamberlain3, A. Carpentier4, L. Cher5, W. Mason6, M. Van den Bent7, S. Hong8, D. Thornton8, H. Fine9; 1University of Heidelberg, Heidelberg, Germany, 2University of Texas, MD Anderson Cancer Center, Houston, TX, United States, 3H. Lee Moffitt Cancer Center, Tampa, FL, United States, 4Hopital Pitie Salpetriere, Paris, France, 5Austin Health, Victoria, Australia, 6Princess Margaret Hospital, Toronto, ON, Canada, 7Erasmus Medisch Centrum, Rotterdam, The Netherlands, 8Eli Lilly and Company, Indianapolis, IN, United States, 9National Cancer Institute, Bethesda, MD, United States Background: ENZ, an oral serine/threonine kinase inhibitor, targets PKC and AKT pathways to induce tumor cell apoptosis and suppress proliferation and angiogenesis. This phase III, multicenter, open-label study compared efficacy and safety of ENZ vs. CCNU in patients (pts) with recurrent, intracranial GBM (WHO grade IV). Methods: Pts were stratified by age, KPS, and disease recurrence, and randomized 2:1 to receive 6-week cycles of 500 mg ENZ daily (1125-mg loading dose day 1) or CCNU (100–130 mg/m2 on day 1). Treatment continued until disease progression or unacceptable toxicity occurred. Assuming a 45% improvement in progression-free survival (PFS) of ENZ over CCNU, 397 pts were to be enrolled to provide 80% power to achieve statistical significance at a one-sided level of 0.025. Secondary endpoints included overall survival (OS), tumor response, safety, and patient-reported outcomes (PROs). The primary PRO analysis was time to deterioration (TtD) for the FACT-Br Trial Outcome Index (TOI; physical and functional well-being plus brain tumor–specific concerns). Results: Enrollment was terminated at 266 pts (ENZ=174; CCNU=92) after a planned interim analysis for futility. Pt characteristics were balanced between arms. Median PFS, OS, and 6-month PFS rates were not different between arms. For ENZ and CCNU, respectively: median PFS=1.5 vs. 1.6 months, HR=1.3 (95% CI: 1.0, 1.7), P=0.08; median OS=6.6 vs. 7.1 months, HR=1.2 (95% CI: 0.9, 1.7), P=0.25; and PFS rate: 11.1% vs. 19.0%, P=0.13. Pts with KPS 90–100 had significantly better PFS and OS on CCNU compared with ENZ. Five (2.9%) and 4 (4.3%) pts had objective response and 67 (38.5%) and 33 (35.9%) had stable disease on ENZ and CCNU, respectively. A total of 251 pts received therapy (ENZ=167; CCNU=84) and were included in the safety analysis. Median duration of therapy was 42 days on both arms. Three pts remain on ENZ therapy for ⩾1 year. The incidence of drug-related adverse events (AEs) was 44% on the ENZ arm and 62% on the CCNU arm. Four pts discontinued ENZ due to drug-related serious AEs (erysipelas, aortic thrombosis, cerebral hemorrhage, and convulsion). Eleven (7%) pts on ENZ died (4 due to AEs, 1 of which was drug-related). On the CCNU arm, all 4 (5%) deaths were disease related. Grade 3/4 hematological toxicities were significantly higher on CCNU (P ⩽0.001); no anemia, neutropenia, or leukopenia occurred on ENZ, and only 1 pt had drug-related thrombocytopenia vs. 21 on CCNU. There were no significant differences in grade 3/4 nonhematological toxicities between arms. Baseline scores for the TOI were not statistically different between arms (P=0.638). Median TtD was 2.3 months for both arms (HR=1.12 [95% CI: 0.77, 1.63], P=0.54). Conclusions: ENZ had a better toxicity profile but did not have superior efficacy or PROs compared with CCNU in pts with recurrent GBM. O23. TARGETED THERAPY WITH AP 12009 FOR RECURRENT OR REFRACTORY HIGH-GRADE GLIOMA: RESULTS UPDATE OF A PHASE IIB STUDY U. Bogdahn1, A. K. Mahapatra2, V. E. Oliushine3, C. Mouli4, V. E. Parfenov5, G. Stockhammer6, S. Ludwig7, G. Wuerth7, H. Heinrichs7, K. H. Schlingensiepen7; 1Neurologische Universitätsklinik, Regensburg, Germany, 2All India Institute of Medical Sciences, New Delhi, India, 3Polenov Neurosurgery Research Institute, St. Petersburg, Russian Federation, 4National Institute of Mental Health and Neurosciences, Bangalore, India, 5Military Medical Academy, St. Petersburg, Russian Federation, 6Universitätsklinik Innsbruck, Innsbruck, Austria, 7Antisense Pharma, Regensburg, Germany Introduction and Objective: High-grade gliomas are very aggressive tumors, characterized by overexpression of transforming growth factor-beta 2 (TGF-beta 2). TGF-beta 2 is one of the most potent immunosuppressors that induces escape from immunosurveillance. TGF-beta 2-specific phosphorothioate antisense oligodeoxynucleotide AP 12009 is targeted to suppress this protein and is used as monotherapy in this indication in clinical trials. Methods: The international Phase IIb study with AP 12009 had an open-label, randomized, and active-control dose-finding design. The main aim of the trial was to compare two doses of AP 12009 (10 μM and 80 μM) with standard chemotherapy (temozolomide or PCV [procarbazine/CCNU (lomustine) vincristine]) concerning overall response rate, survival, and safety. 145 patients with either recurrent or refractory anaplastic astrocytoma (AA, WHO grade III) or recurrent or refractory glioblastoma (GBM, WHO grade IV) were randomized into three groups. AP 12009 was administered as monotherapy via intratumoral, convection-enhanced delivery (CED) using an external portable pump for 6 months with up to 11 treatment cycles (1 cycle: 7 days AP 12009, 7 days isotonic saline). Results: 134 patients (95 GBM and 39 AA) on the study received the drug: 10 μM AP 12009 (N=40), 80 μM AP 12009 (N=49), or standard chemotherapy (N=45). In the entire patient population the survival results for the AP 10 μM group showed a trend for superiority to standard chemotherapy (p=0.082). Even more encouraging results were obtained for AA patients. The overall response rate (CR+PR) and progression rate of the 10 μM AP 12009 group at 14 months were significantly superior to standard chemotherapy. The current overall survival time (in months) is 36.4 (10 μM AP 12009) and 21.7 (standard chemotherapy) (status: Feb. 2008). In both AP 12009 groups, the observed long-lasting tumor regression clearly exceeded the active treatment period. The follow-up period for the Phase IIb study has been extended. Conclusion: For the 10 μM AP 12009 vs. the standard chemotherapy group, patients with recurrent or refractory AA showed a clear current survival benefit of 14.7 months. The overall response rate and progression rate at 14 months were significantly better for the 10 μM AP 12009 group than for the standard chemotherapy group (p<0.05). A multicenter, international, active-control Phase III study with 10 μM AP 12009 monotherapy in patients with recurrent or refractory AA will start in 2008. O24. PHASE I TRIAL OF HIGH DOSE TEMOZOLOMIDE (HDTMZ) WITH PERIPHERAL BLOOD STEM CELL SUPPORT (PBSCS) RESCUE IN RECURRENT HIGH-GRADE GLIOMA (HGG) D. Frappaz1, S. Dussart1, J. Pierga2, J. Bay3, M. Fabbro4, L. Djafari5, M. Sunyach1; 1Centre Léon Bérard, Lyon, France, 2Institut Curie, Paris, France, 3Centre Jean Perrin et CHU, Clermont-Ferrand, France, 4Centre Val D'Aurelle, Montpellier, France, 5Schering Plough, Levallois-Perret, France Background: Despite improvements obtained with frontline treatments prognosis of recurrent HGG still remains dismal. HD chemotherapy suggested a dose-effect relationship in extra CNS lymphoma and germ cell tumors. HDTMZ could be a promising way to overcome resistance of HGG to standard schedule of CT. Methods: This phase I had as principal objective to determine the maximum tolerated dose (MTD) of HD of TMZ with PBSCS rescue in patients with recurrent HGG under 60 years. The MTD was defined as dose level at which 50% of patients treated experienced a DLT (dose-limiting toxicity) defined as grade IV hematological toxicity (lasting more than 2 weeks for neutrophils or 3 weeks for platelets) or a grade III non hematological toxicity. The dose escalation was planned for eight dose levels from 300 to 650 mg/m2/day over 5 days with CSP reinfusion at day 7 according to the Modified Continual Reassessment Method 3 (MCRM). Treatment was administered for one cycle. Results: 30 patients were eligible, but in 10 the phase I could not be performed (8 because sufficient number of PBSC could not be collected, and 2 for other reasons). Thus only 20 received HDTMZ: 16 GBM, 2 AA, and 2 OA. All but one had received previous RT, and 11 had received chemo, mainly nitrosourea. Dose level (mg/m2/day × 5 days) was as follows: 300 (1), 350 (1), 400 (6), 450 (3), 500 (3), 550 (3), and 600 (3). 18/20 had a non-DLT (84 declarations: 22% for prolonged neutropenia and 13% for prolonged thrombopenia) and/or a DLT (3 patients: one hepatic cytolysis grade III at level 400, and 2 others at level 600: see infra). The MTD was reached at 600 mg/m2/day × 5 days: 1 gonalgia grade III and 1 prolonged but partially reversible comatose state. There were 3 partial responses (1 at 550 and 2 at 600 mg/m2), and 8 stable diseases (none at 350 or 600). Conclusions: This final analysis demonstrated that HD of TMZ with CSP reinfusion is feasible but MTD is reached at 600 mg/m2/day × 5 days. The recommended dose is thus 550 mg/m2/day × 5 days. The association with other drugs that have no cross-resistance may then be explored further. O25. TARGETING THE BRAF ONCOGENE IN PEDIATRIC LOW-GRADE ASTROCYTOMAS S. M. Pfister1, W. Janzarik2, M. Remke3, A. Ernst3, A. Gnekow4, G. Reifenberger5, W. Scheurlen6, H. Omran7, A. Kulozik1, P. Lichter3; 1Department of Pediatric Hematology, Oncology and Immunology, Heidelberg, Germany, 2Department of Neurology, University Hospital Freiburg, Freiburg, Germany, 3German Cancer Research Center, Division Molecular Genetics, Heidelberg, Germany, 4Hospital for Children and Adolescents Augsburg, Augsburg, Germany, 5Department of Neuropathology, Heinrich-Heine-University, Düsseldorf, Germany, 6Cnopfsche Kinderklinik, Nürnberg, Germany, 7Department of Pediatric Neurology and Muscle Disorders, University Hospital Freiburg, Freiburg, Germany Pilocytic astrocytomas comprise the most frequent brain tumors in childhood. However, the molecular mechanisms of pathogenesis and tumor recurrence are still poorly understood. In the present study, 66 pediatric astrocytomas of World Health Organization (WHO) malignancy grades I and II were investigated for DNA copy-number aberrations by using array-based comparative genomic hybridization (array-CGH). The most frequent genomic aberration in this tumor series was a circumscribed duplication of the BRAF locus at 7q34 present in 30/66 (45%) of cases with a predominance in pilocytic astrocytomas. Screening the same tumor sample for activating mutations of the BRAF gene, such mutations were identified in 4/66 (6%) tumors, exclusively affecting cases without BRAF duplication, indicating different mechanisms for BRAF activation. Tumors with BRAF duplication showed significantly increased mRNA levels of BRAF and CCND1 as compared to tumors without duplication. Proliferation of cultured tumor cells derived from low-grade gliomas was effectively blocked by pharmacological inhibition of MEK1/2, the immediate downstream target of BRAF as well as by stable knockdown of the BRAF gene using lentivirus-mediated transduction of BRAF-specific shRNAs. Cell cycle analysis revealed a G2/M arrest in cells treated either with MEK1/2 inhibitors or shRNAs targeting the BRAF gene. Taken together, our findings implicate aberrant activation of the Mitogen-Activated Protein Kinase (MAPK) pathway due to gene duplication or activating mutation of BRAF as a common molecular pathomechanism in low-grade astrocytomas and provide a promising novel target for future treatment strategies. O26. MGMT PROMOTER HYPERMETHYLATION IN LOW-GRADE ASTROCYTOMAS M. Eoli, A. Di Stefano, L. Valletta, S. Guzzetti, D. Bianchessi, B. Pollo, A. Silvani, M. Bruzzone, A. Boiardi, G. Broggi, G. Finocchiaro; C. Besta, Milan, Italy Background. O6-methylguanine-DNA methyltransferase (MGMT) is a DNA repair protein that specifically removes mutagenic, carcinogenic, and cytotoxic O6-alkylguanine DNA adducts induced by alkylating agents like nitrosureas. Recent data suggest that loss of MGMT expression due to promoter hypermethylation may occur in the pathway leading to secondary glioblastomas. Methods. Using methylation-specific PCR (MSP) we investigated the inactivation of the DNA-repair gene MGMT by promoter hypermethylation in 54 low-grade diffuse astrocytomas (grade II WHO) obtained from patients who underwent surgery in our institution. Results. Methylation of the MGMT promoter was detected in 22 of 54 tumors (meth+ 40.7%). For all patients, median PFS was 51 months and median OS 141 months. During follow-up, tumor recurred in 34 patients (18 meth+ 82% and 16 meth–50%), while death occurred in 14 cases (9 meth+ 41% and 5 meth–15%). Both the risk of recurrence and the risk of death was statistically significantly higher in tumors with methylation of the MGMT promoter (p=0.02 and p=0.03, respectively, Fisher's exact test). Furthermore, at univariate analysis, median progression-free survival(PFS) and overall survival (OS) were shorter in tumors with methylation of the MGMT promoter (31 vs. 71 months; log-rank test, p=0.01) and (68 vs. not reached months; log-rank test, p=0.03). No association between age, histological subtype, treatments after surgery and OS or PFS were found. Of the 34 patients with progressive disease, 22 had a second surgery: in most of them (17 out of 22) the second diagnosis was high-grade glioma (7 glioblastomas, 5 anaplastic astrocytomas, and 5 anaplastic oligoastrocytomas). Three patients also had a third surgery: the last diagnosis was anapalstic astrocytomas in 1 and glioblastoma in 2. Malignant PFS was shorter in tumors with methylation of the MGMT promoter (40 vs. n.r. months; log-rank test, p=0.052). Furthermore, during the follow-up in 9 patients the tumor changed from low grade to glioblastomas: the percentage of tumors that became glioblastomas (36% vs. 14%) was higher in the meth+ group and also the time occurred was shorter (81 vs. n.r.). Both camparisons did not reach statistical significance due to the small number of cases. Conclusions. The findings indicate that in low-grade astrocytomas MGMT methylation is associated with tumor recurrence and is predictive of progression to a more malignant phenotype. O27. PROTRACTED LOW DOSE TEMOZOLOMIDE (TMZ) AS INITIAL TREATMENT FOR PROGRESSIVE LOW-GRADE OLIGODENDROGLIAL TUMORS: A PHASE II AINO (ITALIAN ASSOCIATION FOR NEURO-ONCOLOGY) STUDY E. Trevisan1, E. Laguzzi1, D. Guarneri1, C. Bomprezzi2, M. Caroli3, B. Leoncini1, R. Soffietti1, R. Rudà1; 1Neuro-Oncology Unit, Torino, Italy, 2University, Ancona, Italy, 3University, Milano, Italy Background. Protracted administration of low doses of TMZ offers potential advantages over the standard TMZ schedule, leading to increased MGMT depletion, which may enhance the antitumor activity of alkylating agents. Few data are available on the efficacy and tolerability of protracted low-dose TMZ in patients with low-grade gliomas. Patients and Methods: Since September 2004 we enrolled in an ongoing multicenter phase II study 31 patients (25 evaluable for response), with a median age of 41 yrs and a median KPS of 90. Mild enhancement on MRI was present in 36% of patients. Pathological diagnosis according to WHO (2007) was oligodendroglioma grade II in 15 and oligoastrocytoma grade II in 10. TMZ was administered orally at 150 mg/m2/day, days 1–7 and 15–21 every 4 weeks, up to 18 cycles or tumor progression or unacceptable toxicity. Patients received prophylaxis against Pneumocystis carinii when lymphocytes <500 mm3. Patients underwent clinical and MRI assessment every 1 and 3 months, respectively, and monitoring by PET with methionine was performed in selected centers. The primary endpoint was the response rate on MRI, and secondary endpoints were the progression free-survival (PFS) at 6 and 12 months, median PFS, quality of life, and toxicity. The analysis of 1p/19q status by FISH and MGMT promoter methylation by PCR were mandatory. Results: The overall response rate (PR+MR) was 52% (13/25) with PR 32% and MR 20%, and disease control rate (PR+MR+SD) was 92%. Median time to maximum radiographic response was 6 months. Clinically, 65% (11/17) of patients improved, particularly those with uncontrolled seizures. 20/25 patients are still free from tumor progression with a median follow-up of 14 months (range 4–39). Combined 1p/19q or isolated 1p deletion was not associated with response on FLAIR images, whereas there was a trend toward an association between response of the enhancing tumor and 1p/19q codeletion. Grade 3 lymphopenia was observed in 45% of patients. Conclusions. TMZ 1 week on/1 week off, as initial treatment for progressive low-grade oligodendroglial tumors, seems more efficacious than standard dose TMZ and is relatively safe. When patients develop cumulative lymphopenia, a conversion to standard dosing is feasible. Updated results, correlation between MGMT promoter methylation, 1p/19q loss and response, and monitoring with PET will be presented. O28. TUMOR GROWTH RATE PREDICTS TRANSFORMATION-FREE SURVIVAL IN ADULT LOW-GRADE GLIOMAS J. H. Rees1,2, J. S. Winston1,2, R. Jager1,2, C. Benton1, G. Brasil Caseiras1,2, P. S. Tofts3, D. Altmann4, D. Tozer2, A. D. Waldman5,6; 1National Hospital for Neurology and Neurosurgery, London, United Kingdom, 2UCL Institute of Neurology, London, United Kingdom, 3Brighton and Sussex Medical School, Brighton, United Kingdom, 4London School of Hygiene and Tropical Medicine, London, United Kingdom, 5Imperial College, London, United Kingdom, 6Charing Cross Hospital, London, United Kingdom Objective: To investigate the prognostic value of growth rate in adult patients with low-grade gliomas (LGG). Methods: An observational cohort study was conducted on 50 adult patients with LGG. Patients received no treatment except anti-epileptic drugs until malignant transformation was suspected. Two magnetic resonance imaging (MRI) studies, approximately 6 months apart, were used to determine growth rate based upon calculation of tumor volume on FLAIR MRI. Primary endpoints were death from any cause or clinical/radiological transformation of the tumor. Results: Growth rates measured over a 6-month period from study entry were highly variable between patients (range: –4.9 to 38.5 ml/yr; mean=16.8 ml/yr; median=17.5 ml/year). Patients with faster growing tumors reached the endpoint earlier (log-rank test: Chi21=13.4; p=0.0002; relative risk of endpoint=3.5; 95% confidence interval: 1.6–7.8). Cox regression analysis showed that faster growth rate was an independent prognostic factor (allowing for confounding variables including tumor size, patient age and gender, tumor histology, and whether the tumor crossed the midline). For every 10 ml/year increase in growth rate, the increased hazard of the endpoint (risk of malignant transformation or death) was 2.41 (95% CI: 1.30–4.46; p=0.004). Conclusions: Growth rate is a readily measured predictor of early transformation in LGG. The data suggest that LGG growth is best considered a continuous variable, with higher growth rates associated with earlier transformation. O29. LOW-GRADE ASTROCYTOMA IN CHILDREN: SINGLE INSTITUTIONAL EXPERIENCE IN 143 PATIENTS O. Cruz, N. Perez, E. Rodriguez, M. Suñol, V. Cusi, C. De Torres, G. Garcia-Fructuoso, A. Guillen, A. Parareda, J. Mora; Hospital St Joan de Deu, Esplugues de Llobregat, Barcelona, Spain Introduction: Astrocytomas are the most frequent brain tumors in children, mainly low-grade neoplasias, but represent a very heterogeneous group of tumors. Aim: To review the clinical experience with low-grade astrocytomas (LGA), their histopathological and clinical features, therapeutic approach, and prognostic features. Patients and Methods: A retrospective study of children (0–18 y), diagnosed with LGA within a 30-year period (1974–2004) was performed. Histology variables included histological pattern, tumor classification (edited WHO version), and immunohistochemistry (IHC) in a tissue microarray for GFAP, WT1, p53, and ki67 expression. Results: A total of 143 patients managed at our institution for LGA were included. Average age at diagnosis was 7.4 y (SD 4.3). Seventy-three (51%) patients were male. Neurofibromatosis was documented in 11 cases (8.1%). Initial symptoms were headache (35.8%), seizures (20.9%), motor deficit (16.4%), visual (10.4%), and ataxia (9.7%). 84 tumors (58.7%) were infratentorial. Primary sites were cerebellum (41.2%), hemispheres (21.3), optic pathway (14%), brainstem (14%), spinal tumors (6.6), or mesencephalic (2.9%). Fifty tumors (39.7%) sited at midline and 30% each were right and left. Hydrocephalus was present in 61 patients (42.7%) and a mixed solid-cystic pattern was seen in 80% of cases. Only 4 patients had metastases (2.9%). Surgery was complete in 60 patients (45.1%). 27 patients had two or more resections (18.9%). A derivative procedure for hydrocephalus was required in 37 patients (27.4%), 31 of them currently device-dependent (23.1%). Pathological review classified 93 tumors as WHO grade-9 (73.8%), and 33 as grade II tumors (13 as fibrillary and 3 as pleomorhic xantoastrocytomas). IHQ for p53 was negative, save for 5 patients, all grade II tumors; Ki67 expression was >5% in 92.6% of cases, and WT1 (nuclear) 59.7%. No significative differences in survival were found among histological subtypes or IHQ pattern, but a trend for higher mortality in WT1 positive tumors was appreciated. Neurological complications were the most frequent in the immediate postoperative period (41 [31.3%]). Adjuvant therapy was given in 53 (37%) cases: radiation therapy in 36 patients (25%) and chemotherapy in 22 patients (15.3%). Currently, 15 (11.3%) patients have died of disease, 67 (50.4%) patients are alive with no evidence of disease, and 51 (38.3%) patients are alive with disease (median follow-up of 200 months). An age younger than 12 months was a prognosis factor, as 4 of 5 infants have died. Long-term secondary effects have been documented in 54 (37.8%) patients, 17 with more than one sequel. Forty-nine (35.5%) cases are lost to follow-up when discharged to adult care. Conclusions: LGA in infants have an unfavorable prognosis. We are not aware of the current status of the eldest patients; long-term follow-up is necessary, but unfeasible in the actual health setting. O30. TEMOZOLOMIDE IN PRIMARY GLIOMATOSIS CEREBRI: FINAL RESULTS OF A RETROSPECTIVE STUDY OF THE AINO (ITALIAN ASSOCIATION FOR NEURO-ONCOLOGY) R. Rudà1, E. Laguzzi1, A. Pace2, C. M. Carapella2, M. Riva3, M. Salvati4, A. Silvani5, L. Fariselli5, M. Caroli6, R. Soffietti1; 1Division of Neuro-Oncology, Torino, Italy, 2Cancer Center Regina Elena, Rome, Italy, 3Division of Neurology, Lodi, Italy, 4Division of Neurosurgery La Sapienza, Rome, Italy, 5Neurological Institute C. Besta, Milano, Italy, 6Division of Neurosurgery Policlinico, Milano, Italy Background: The optimal management for patients with primary gliomatosis cerebri (GC) is still unknown, and some studies suggest that temozolomide could be useful as an upfront treatment. Patients and Methods: Between 2000 and 2006, 53 patients with biopsy-proven primary GC were treated with temozolomide (200 mg/m2/day for 5 days every 4 weeks until tumor progression or unacceptable toxicity) either upfront (31) or at relapse after prior radiotherapy/chemotherapy with nitrosoureas (22). Histological diagnoses were as follows: astrocytoma in 17 patients, oligodendroglioma in 6, oligoastrocytoma in 4, gemistocytic astrocytoma in 2, anaplastic astrocytoma in 9, anaplastic oligoastrocytoma in 2, anaplastic glioma in 6, glioblastoma (focal area) in 1, and glial proliferation consistent with GC in 6. Median age was 51 years (14–81), with 31 males and 22 females, and a median Karnofsky score of 80. Thirty-three out of 53 patients (62%) had minimal contrast enhancement on MRI. Response was evaluated based on measurable changes in tumor area using T2-weighted and Flair images. Results: Median number of cycles was 6 (range 2–26). Patients receiving upfront TMZ had a response rate (PR+MR) of 29%, a time to tumor progression (TTP) of 9.9 mos (1–69) and a progression-free survival at 6 months (PFS6) of 61%. Patients receiving TMZ at relapse after previous treatments had a response rate (PR+MR) of 23%, a TTP of 5.3 mos, and a PFS6 of 50%. Neurologic improvement (more commonly reduction of seizures) was identical (31%) in both groups. Among the 25 patients for whom 1p/19q status was available, response to TMZ was significantly associated with 1p-19q codeletion (p<0.05);conversely, response was not associated with histologic type or tumor grade. Overall survival (from diagnosis) was 14.9 months. After multivariate analysis (Cox regression model), Karnofsky status and 1p/19q codeletion retained an independent prognostic significance. Toxicity of TMZ was mild. Conclusions: About one third of patients with primary gliomatosis cerebri benefit from treatment with temozolomide, and response is higher among patients treated upfront and with 1p/19q codeletion. Dose-dense schedules of temozolomide could improve the results. A multicenter phase II study of the AINO with upfront dose-dense TMZ is ongoing to delay large-field radiation, and material for 1p/19q status and MGMT analysis is being collected. O31. DEGREE OF BLOOD-BRAIN BARRIER DISRUPTION AND CUMULATIVE TOTAL DOSE INTENSITY IN THE TREATMENT OF PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA D. F. Kraemer1, L. Angelov2, N. D. Doolittle3, T. Siegal4, D. Peereboom2, K. Jahnke3, E. Shalom4, G. Barnett2, J. McGregor5, E. A. Neuwelt3; 1Oregon State University, Portland, OR, United States, 2Cleveland Clinic, Cleveland, OH, United States, 3Oregon Health & Science University, Portland, OR, United States, 4Hadassah Hebrew University Hospital, Jerusalem, Israel, 5Ohio State University, Columbus, OH, United States Background: The effectiveness of many chemotherapeutic agents for malignant brain tumors is limited by the blood-brain barrier. Approaches such as blood-brain barrier disruption (BBBD) improve delivery of these agents to the brain. This report describes the degree of disruption for BBBD procedures and the impact of a cumulative degree of disruption score (as a measure of total dose intensity) on survival in a large case series of patients with newly diagnosed primary central nervous system lymphoma (PCNSL). Methods: A previously reported case series of 149 PCNSL patients treated at four centers with a methotrexate-based regimen in conjunction with BBBD, without up-front whole brain radiotherapy, was evaluated for degree of disruption for each procedure. Individual disruptions are rated nil, moderate, good, or excellent or intra-arterial only (i.e., no disruption performed). These degree-of-disruption data are summarized and used, along with number of disruptions, as time-dependent covariates to predict overall survival. Analyses adjust for potential confounders including performance status, age, gender, surgical resection, discontinuation due to complications, and intraocular disease. Results: The majority of 2,080 procedures were rated moderate (35%) or good (36%), while fewer were rated nil (11%) or excellent (10%). Mean cumulative degree of disruption score was 44 (SD 28). The correlation between degree of disruption on two consecutive days of therapy was relatively low (Spearman r=0.39, p<0.0001). Cumulative degree of disruption score (hazard ratio 0.97, 95% CI: 0.96, 0.98) was a significant predictor of survival. Controlling for potential confounders did not substantially change the hazard estimate or its p-value. Discussion: These results support the association between degree of disruption and survival in patients with PCNSL. The low correlation between disruptions on consecutive days suggests the degree of disruption depends on more than patient factors. Future research will explore associations of degree of disruption with complications. Conclusion: There is a statistically significant association between degree of disruption, total dose intensity, and survival supporting the efficacy and importance of blood-brain barrier disruption for treating PCNSL patients. O32. METHOTREXATE, PROCARBAZINE AND CCNU AS CHEMOTHERAPY-ONLY TREATMENT FOR PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA IN YOUNG PATIENTS: A FRENCH NEURO-ONCOLOGY ASSOCIATION (ANOCEF) STUDY A. M. P. Omuro1, L. Taillandier2, O. Chinot3, C. Carnin2, M. Barrié3, C. Soussain4, M. Tanguy4, M. Sierra Del Rio4, V. Leblond4, K. Hoang-Xuan4; 1Memorial Sloan-Kettering Cancer Center, New York, NY, United States, 2CHU Nancy, Nancy, France, 3CHU La Timone, Marseille, France, 4CHU Pitié-Salpêtrière, Paris, France Background: Methotrexate (MTX)-based chemotherapy followed by whole brain RT improves survival in primary CNS lymphoma (PCNSL) patients but is associated with a high risk of RT-related neurotoxicity (NT). Deferring RT does not seem to compromise survival in the elderly (>60 years), but utilizing such an approach in younger patients remains controversial. In this study we report outcomes of an innovative MTX-based regimen for PCNSL patients younger than age 60 and seek to investigate whether withholding RT is an acceptable option for selected patients. Methods: We reviewed records of all patients <60 years with confirmed PCNSL seen in 3 French institutions from 1994 to 2003. Through prior agreement among institutions, patients were offered a standardized treatment consisting of an induction chemotherapy with MTX (3 g/m2 on days 1, 10, and 20), CCNU (40 mg/m2 on day 1), procarbazine (60 mg/m2 on days 1–7), methylprednisolone (120 mg/m2 on days 1–20) and IT MTX (15 mg), cytarabine (40 mg) and methylprednisolone (40 mg on days 1, 5, 10 and 15). Patients with a complete response (CR) proceeded to a maintenance chemotherapy consisting of 5 monthly cycles with same doses of MTX on day 1, CCNU on day 1, procarbazine days 1–7, and same IT chemotherapy on day 1; those patients received no further treatment. Patients with less than a CR to induction were treated on an individual basis and typically received consolidation with RT or high-dose chemotherapy (HDC) with stem cell rescue. Results: Among the 64 included patients, median age was 47 (19–60), median KPS was 70 (20–100), and 41 (64%) were men. For the entire population, median progression-free survival (PFS) was 13 months and median overall survival (OS) has not been reached (median follow-up: 54 months). Ninety percent of patients responded to induction treatment (CR: 52%; PR: 38%). Consolidation or salvage treatment with RT has been given to a total of 27 patients, and HDC to 23. For the 26 patients who completed maintenance chemotherapy and received no further treatment, median PFS was 36 months. Grades 3/4 hematotoxicity developed in 18 patients, nephrotoxicity in 2, and NT in 6 (none in the chemotherapy-only treated patients). Two toxic deaths occurred. KPS⩾60 was associated with increased OS (p=0.017). Conclusions: Deferring RT in chemosensitive patients seems to decrease PFS but not OS, with minimal NT. HDC and RT are effective salvage treatments. Further studies on the upfront use of RT versus HDC in younger patients are warranted. O33. EARLY RADIOGRAPHIC RESPONSE TO CHEMOTHERAPY PREDICTS FAVORABLE OUTCOME IN PATIENTS WITH PRIMARY CNS LYMPHOMA H. Pels1, A. Juergens1, I. Schirgens2, A. Glasmacher2, H. Schulz3, A. Engert3, V. Diehl3, M. Linnebank2, G. Schackert4, H. Reichmann4, F. Kroschinsky4, M. Vogt-Schaden5, G. Egerer5, U. Bode2, M. Deckert3, R. Fimmers2, K. Fliessbach2, T. Klockgether2, I. G. H. Schmidt-Wolf2, U. Schlegel1; 1Ruhr-Universität Bochum, Bochum, Germany, 2University of Bonn, Bonn, Germany, 3University of Cologne, Cologne, Germany, 4University of Dresden, Dresden, Germany, 5University of Heidelberg, Heidelberg, Germany Introduction: The identification of prognostic factors in patients with primary CNS lymphoma (PCNSL) and the validation of prognostic scores is useful for stratification of patients in randomized trials and essential for a critical comparison of treatment results of nonrandomized clinical trials. Moreover, the attribution of cancer patients to different risk groups may lead to more sophisticated and risk tailored therapeutic strategies. The prognostic factors identified for PCNSL in immunocompetent individuals as defined by the International Extranodal Lymphoma Study Group are age, performance status, elevated lactate dehydrogenase serum levels, high protein concentration of the cerebrospinal fluid, and involvement of deep structures of the brain. The objective of this study was to evaluate the prognostic impact of early tumor response assessed by magnetic resonance imaging (MRI) in immunocompetent patients with PCNSL receiving systemic and intraventricular chemotherapy. Patients and Methods: From 09/1995 to 12/2002, 88 patients with PCNSL (median age 62 years) were enrolled in a pilot/phase II study evaluating MTX-based high-dose chemotherapy without radiotherapy (“Bonn-Protocol”). MRI scans were performed after two and after six courses of chemotherapy, and radiographic response was assessed according to the Macdonald criteria. Overall survival (OS) and time-to-treatment failure (TTF) were measured. Results: Patients achieving a complete radiographic response already after two courses of chemotherapy (n=18) had a significantly longer median OS (not reached) and median TTF (not reached) than patients with complete response only after termination of treatment (n=24) (OS: 55 months; TTF: 32 months) (p=0.01). Conclusion: In addition to the prognostic factors defined by the International Extranodal Lymphoma Study Group, early tumor response assessed by MRI already in the early stage of treatment was shown to be a highly predictive prognostic factor for both OS and TTF in patients with PCNSL and treated with combined systemic and intraventricular chemotherapy. Patients without rapid response to chemotherapy possibly should be switched to alternative treatment strategies in future. O34. PRIMARY PINEAL TUMORS—OUTCOME AND PROGNOSTIC FACTORS: A STUDY FROM THE RARE CANCER NETWORK (RCN) S. Villà1, R. Miller2, M. Krengli3, H. Abusaris4, B. O. Baumert5, S. Servagi-Vernat6, S. Igdem7, A. Lucas8, S. Boluda9, R. O. Mirimanoff10; 1HU Germans Trias. ICO Badalona, Badalona. Barcelona, Spain, 2Mayo Clinic, Rochester, MN, United States, 3Univ of Piemonte Orientale, Novara, Italy, 4Dr. N. Verbeeten Institute, Tilburg, The Netherlands, 5Grow Research Institute. MAASTRO Clinic, Maastricht, The Netherlands, 6University Hospital, Besançon, France, 7Metropolitan Hospital, Istambul, Turkey, 8ICO DiR, Hospitalet, Spain, 9HU Bellvitge, Hospitalet, Spain, 10HU Vaudois, Lausanne, Switzerland Purpose: Primary pineal tumors (PPT) are uncommon in the context of pineal gland neoplasms. Outcome and results of therapy could depend on several factors including histological subtypes, staging at diagnosis, type of surgery (S), doses of radiotherapy (RT), and administration of chemotherapy (CT). The purpose of this analysis has been to better define of outcome and possible prognostic factors in the era of modern imagery, surgery and adjuvant treatment. Materials and Methods: This multicenter retrospective study from the RCN recruited 35 patients during a period between 1994 and 2006. Median age of patients was 36 (2–76), and the male/female ratio was 1/2. The mean size of tumors was 19 mm (9–55). Type of surgical resection was as follows: biopsy in 12 cases, partial resection in 13, and total resection in 8 (2 cases were unknown). In 15 cases postoperative imaging within the first 72 hours was achieved. In 9 cases RT doses to the tumor bed (CTV) were lower than 54 Gy, and in 25 >54 Gy. CSI was delivered in 13 patients. CT was administered in 12 patients (platin-based in 8). Results: At the time of diagnosis, one patient presented with intracranial metastases, and 7 patients presented with spinal cord dissemination. Histological subtypes were pineoblastoma (PNB) in 21 patients, pineocytoma (PIN) in 8 patients, and pineocytoma with intermediate differentiation (PID) in 6 patients (9 samples were reviewed by an independent pathologist). In 15 cases, immuno-histochemical analysis was available (10 PNB, 2 PIN, 3 PID). All samples showed positivity for synaptophysin, 5 samples (3 PNB, 1 PIN, 1 PID) for neuron specific enolase (NSE), and 3 samples for GFAP, cd5leu7, and ulex europeus lectin, respectively. MIB-1/Ki67 was high in 3 cases (all PNB), moderate in 2 (1 PNB, 1 PIN), and low in one PNB. Fifteen patients relapsed (14 PNB and 1 PIN). Sites of relapse were the following: inside RT volumes (16 locations), outside in 6 locations, and both in 3 locations. Overall median survival time for all the series was not reached. Median of disease-free survival was 82 months. In univariate analysis age was the only significant variable (p < 0.003) in favor of patients older than 36 y. A trend for poorer survival was observed for PNB patients. Neither surgical procedures, nor RT doses or CT influenced OS. Late side effects of RT were dementia, leukoencephalopaty, or memory loss in 7 cases, occipital ischemia in 1, G3 seizures in 2 cases, long-term leucopenia 1 case, and G4 thrombopenia in 1. Side effects of CT were G3 neutropenia in 4 cases, G2 anemia in 2, G4 pancitopenia in 1, G4 vomiting in 1, renal failure in 1 and G2 thrombopenia in another case. Conclusions: (1) Combination treatments for PPT achieved good overall survival. (2) Age and probably histological subtypes influenced survival in our series. (3) And the prevalence of chronic toxicity suggests that new strategies in RT and CT could be advisable. O35. METASTATIC MEDULLOBLASTOMA CHANG STAGING SYSTEM REVISED C. Dufour1, J. Micheli2, A. Fourcade1, A. Laplanche1, C. Kalifa1, D. Couanet1, J. Grill1; 1Gustave Roussy, Villejuif, France, 2CHU, Amiens, France Background: Medulloblastoma is a highly malignant primary brain tumor with tendency to metastasize. For evaluating metastases, Chang's staging system takes into consideration their locations but not their radiological aspects. The aim of this study was to correlate metastasis phenotypes and their evolution to patient's outcome. Patients and Methods: The authors reviewed outcomes of 99 consecutive patients (median age, 4.5 y; range, 0.5–14.5) affected by disseminated medulloblastoma treated at Institute Gustave Roussy, between 1989 and 2005. Metastatic disease was assessed using Chang's staging system: M1, CSF cytology positive for tumor cells at least 8 days after initial surgery (n=19); M2, evidence of intracranial seeding on gadolinium-enhanced MRI scan (n=22); M3, evidence of tumor seeding down the spinal cord on gadolinium-enhanced MRI of spine (n=58). Metastases were also evaluated by imaging (nodular, 32 pts; linear, 13; mixed, 35; invasion CSF, 19) and site extension (local, 26 pts; extensive, 54; invasion CSF, 19). During the study period, 33 patients were treated with conventional chemotherapy followed by standard craniospinal irradiation, 15 with high-dose chemotherapy (HDCT) with stem cell rescue (ASCT) followed by local radiation, and 51 with HDCT with ASCT followed by age-adapted craniospinal irradiation. All patients received induction chemotherapy with one or two cycles of carboplatin-etoposide. Results: After induction chemotherapy, 28 pts were in CR and 53 in PR. At the end of chemotherapy, 41 children were in CR and 33 in PR. The median follow-up was 7.8 y (range, 2.2–14.7). At 5 y, EFS and OS were 38% and 44%, respectively. 5-year OS for patients with M1, M2, and M3 tumors were 45%, 54%, and 40%, respectively (p=ns). 5-year OS was 58% for patients with isolated metastatic disease and 33% for patients with extensive disease (p=0.032). 5-year OS for patients with positive CSF was 45%, linear metastases 39%, nodular 58%, and mixed 58%. 5-year OS was 54% for patients achieving CR at end of chemotherapy compared to 27% for patients failing to achieve CR (p=0.0003). Conclusions: Concerning this study, Chang's staging system does not play a predictive role for prognosis. Metastasis radiological aspects may have an impact on survival in pediatric disseminated medulloblastoma. O36. ATYPICAL TERATOID/RHABDOID TUMORS (AT/RTS) IN THE PEDIATRIC POPULATION OF AUSTRIA: A POPULATION-BASED STUDY, 1996–2006 A. Woehrer1, T. Waldhoer2, A. Azizi3, I. Leisser1, T. Czech4, H. Budka1, J. A. Hainfellner1, I. Slavc3, C. Haberler1, 1A. W. on behalf of the Austrian Brain Tumor Registry; 1Institute of Neurology, Medical University of Vienna, Vienna, Austria, 2Center for Public Health, Department of Epidemiology, Medical University of Vienna, Vienna, Austria, 3Department of Pediatrics, Medical University of Vienna, Vienna, Austria, 4Department of Neurosurgery, Medical University of Vienna, Vienna, Austria Introduction: Atypical teratoid/rhabdoid tumors (AT/RTs) are highly malignant embryonal brain tumors. They were first described as a distinct tumor entity in 1987 and included in the WHO CNS tumor classification in 1996. Histopathologically, AT/RTs display a complex morphology of rhabdoid, primitive neuroectodermal, epithelial, and mesenchymal components which may render the differential diagnosis from other malignant brain tumors, especially embryonal tumors difficult. AT/RTs occur predominantly in children <3 years. In the literature a prevalence of 1%–2% of pediatric brain tumors has been described. However, so far epidemiological data are scarce. Objectives: We conducted a population-based study on primary malignant, high-grade (WHO grade III+IV) pediatric brain tumors for identification of AT/RTs and generation of epidemiological data on this tumor type in the pediatric population of Austria. Materials and Methods: All 7 centers (16 departments of pathology and pediatrics) engaged in the diagnosis and management of brain tumor patients in Austria participated in a nation-wide survey. All primary malignant CNS tumors (WHO grade III+IV) occurring in children <15 years, newly diagnosed from 1996 to 2006 were collected. In cases where tumor tissue was available a central histopathological review was performed. Additionally, immunohistochemical INI1 protein expression status, which has been recently described as valuable tool to delineate AT/RTs from other malignant brain tumors, was systematically analyzed. Results: A total of 268 cases have been identified so far. 93% underwent surgery. Tumor tissue was available in 211 cases and 18/211 of the cases were diagnosed on review as AT/RT. Among these, 10/18 (56%) were primarily reported as AT/RTs, while the others, 8/18 (44%) were originally classified as embryonal CNS tumors (medulloblastoma, sPNET, ependymoblastoma), Ewing sarcoma, or sarcoma. This would refer to an age-standardized incidence rate of AT/RTs in children of 0.4/1,000,000 person-years. Median age of AT/RT patients at diagnosis was 1.4 years, and 72.2% occurred in children <3 years. In this age group AT/RTs constituted the most common tumor (21.3%) followed by medulloblastoma (18.0%) and sPNET (14.8%). Conclusions: AT/RTs mainly occur in very young children (<3 years). In this age group they represent the most common highly malignant brain tumor type. Accurate histopathological diagnosis including INI1 immunohistochemistry is important for identification of AT/RTs. O37. EARLY TREATMENT RELATED NECROSIS IS ASSOCIATED WITH PROLONGED SURVIVAL IN MALIGNANT GLIOMAS A. M. Demopoulos1, B. A. Napolitano2, D. Chalif3, K. Black4; 1Division of Neuro-Oncology, Dept. of Neurology, Manhasset, NY, United States, 2Biostatistics Unit, Feinstein Institute for Medical Research, Manhasset, NY, United States, 3Department of Neurosurgery, Manhasset, NY, United States, 4Division of Neuro-Radiology, Dept. of Radiology, Manhasset, NY, United States Imaging changes in malignant brain tumor patients may represent treatment effects rather than progression of disease [deWit MC 2004]. Pathological material from such patients generally reveals regions of bland acellular necrosis, admixed with a minority of active tumor. Such changes have been called early treatment related necrosis (ETRN) by some investigators [Chamberlain MC 2007]. ETRN has important ramifications for patient care and clinical trial design. When ETRN occurs, effective regimens may be discontinued, investigative agents may appear more effective than they are, and clinical trials designed around progression free survival endpoints may prematurely terminate. ETRN's association with overall survival is unknown. We report a retrospective chart review of 65 newly diagnosed, high-grade gliomas treated at a single institution with concurrent radiotherapy and temozolomide. We identify eight patients with ETRN, defined as pathological findings inconsistent with tumor growth (n=6) and >25% radiographic improvement despite therapy discontinuation (n=1) or no therapy change (n=1). ETRN occurred in all eight patients within six months of completing radiotherapy. We compared ETRN overall survivals with the entire cohort (n=57); those who progressed within six months of completing radiation therapy (n=23), but did not meet the definition of ETRN; and patients who progressed during radiation therapy (n=7). Patients who progressed during radiotherapy had the shortest median overall survival (OS) (n=7, OS=4.6 months, 95%CI=3.0–8.8) when compared with all other patients (n=58, OS=20.1 months, 95%CI=15.1–23.9). This result was highly statistically significant (log-rank p<0.0001). ETRN patients had a trend to longer survival(n=8, OS=21.5, 95%CI=15.9–NR) when compared with all other patients (n=57, OS=16, 95%CI=12.1–22), but this result was not statistically significant (log rank p<0.2713). However, patients with ETRN had longer median overall survivals when compared to other patients who progressed within six months of radiotherapy (n=23, median OS=9, 95%CI=5.5–12) even when patients who progressed during radiotherapy (i.e., those known to have particularly short survival) were excluded from the comparison group (n=16, median OS=11.6, 95%CI=8.9–16.1). Both results were significant, log-rank p<0.0016 and p<0.0067, respectively. To our knowledge, this is the first demonstration of a statistically significant difference in survival in early treatment related necrosis patients. The data also provide valuable information that progression during chemoradiotherapy is associated with a particularly poor outcome, previous data examined progression during radiation therapy alone [Gaspar LE 1993]. O38. IMPACT OF EXTENT OF RESECTION AND OUTCOME TO ADJUVANT CHEMOTHERAPY: A META-ANALYSIS OF THREE EORTC STUDIES M. J. van den Bent1, R. Stupp2, J. Hildebrand3, A. A. Brandes4, R. Mirimanoff5, W. Mason6, M. Weller7, J. G. Cairncross8, J. Delattre9, D. Lacombe10, T. Gorlia10; 1Daniel den Hoed Cancer Center, Rotterdam, The Netherlands, 2Multidisciplinary Oncology Center, University of Lausanne Hospitals, Lausanne, Switzerland, 3Hopital Universitaire Erasme, Brussels, Belgium, 4Medical Oncology Department, Bellaria-Maggiore Hospital, Bologna, Italy, 5Dept Radiotherapy, University of Lausanne Hospitals, Lausanne, Switzerland, 6St Margaret Hospital, Toronto, ON, Canada, 7University Hospital Zurich, Zurich, Switzerland, 8University of Calgary, Calgary Health Region, Calgary, AB, Canada, 9Service de Neurologie Mazarin Hôpital de la Salpêtrière, Paris, France, 10EORTC HeadQuarters, Brussels, Belgium Background. Extent of resection is an important prognostic factor in most trials in high-grade glioma. Theoretically, a decreased tumor load prior to the start of adjuvant chemotherapy may influence efficacy of adjuvant treatment. We explored within three randomized trials if a resection impacted the outcome to adjuvant chemotherapy. Material and Methods. Exploratory and pooled subgroup analysis in three prospective randomized trials (EORTC 26882, adjuvant dibromodulciterol [DBD] and BCNU in high-grade glioma; EORTC 26951, adjuvant PCV in anaplastic oligodendroglioma; EORTC 26981, concurrent and adjuvant temozolomide in glioblastoma; n = 1356) on the influence of the extent of resection on overall outcome and on outcome to adjuvant treatment. In all trials extent of resection was recorded as reported by the operating neurosurgeon. Primary endpoint of the analysis was overall survival. The study compared resection vs. biopsy and biopsy vs. partial resection vs. complete resection. A p value of <0.05 was considered statistically signficant. A Cox proportional analysis was used to control for other major prognostic factors (performance status and age). Results. In two trials a statistically significant risk reduction was observed after adjuvant chemotherapy in the resected patients, but in none of the trials in the biopsied patients (table, adjusted analysis). Although in the pooled analysis adjusted for main prognostic factors the risk reduction of adjuvant chemotherapy was significant in the resected patients (n = 1,138, HR [95% CI] 0.71 [0.62–0.81]) but not in the biopsied patients (n = 218; HR [95% CI] 0.89 [0.67–1.19]), the adjusted interaction test was negative (p = 0.24). In younger patients (<50 yrs) the interaction test was positive (p = 0.03), but not in the group with good performance status (PS 0 and 1, p = 0.28). Differentiating between partially and completely resected patients did not impact upon the treatment effect. Conclusion. Although efficacy of adjuvant chemotherapy appears to be more pronounced in patients who have undergone a resection, this is also influenced by other prognostic factors (age, PS) and statistical significance was not reached. Heterogeneity between the trials and the limited numbers of biopsy patients may have influenced the present findings. O39. HYPOFRACTIONATED RADIOTHERAPY WITH INTENSITY MODULATED ARC THERAPY (IMAT) PLUS ADJUVANT TEMOZOLOMIDE FOR PRIMARY GLIOBLASTOMA MULTIFORME N. D'Abbiero1, A. Pisanello2, G. De Berti3, C. Iotti1, T. Palmieri1, D. Ramundo1, M. Galeandro1, M. Ruggieri1, S. Riccardi4, D. Lambertini4, N. Bizzocchi4, R. Ghadirpour5, L. Armaroli1, N. Marcello2; 1Radiotherapy Unit, Reggio Emilia, Italy, 2Neurology Unit, Reggio Emilia, Italy, 3Neuro-Radiology Unit, Reggio Emilia, Italy, 4Medical Physics, Reggio Emilia, Italy, 5Neuro-Surgery Hub-Spke Parma-Reggio Emilia, Reggio Emilia, Italy Purpose: Multimodality treatments with surgical resection followed by standard radiotherapy (60 Gy/2Gy fr) and adjuvant chemotherapy in patients with glioblastoma multiforme (GBM) have produced significant results even though the prognosis remains poor. Therefore exploring hypofractionated regimen using new radiotherapy technique is an attractive strategy. Recently the advance of technology has permitted to plan radiation treatment with high comformal index and important sparing of normal tissue. The rationale of this study was to combine the potential radiobiologic advantage of hypofractionation to GBM with highly conformal radiotherapeutic IMAT technique allowing to perform radiation treatment with a sharp dose gradient such as stereotactic radiotherapy treatments (SRT) even on PTV over 3 cm diameter. The authors present their results on hypofractionated IMAT radiotherapy regimen in the treatment of patients with GBM. Methods and Material: Thirty eligible patients were accrued between October 2002 and September 2005. All patients underwent surgery (craniotomy and cytoreduction of the mass). Planning CT-MRI was obtained for every patient in treatment position with immobilization device (head mask). PTV1: surgery field +/- residual disease (CTV1) was confirmed with MRI T1-weighted (with gadolinium) plus 3-mm margin for geometric uncertainty; PTV2: perilesional edema by MRI T2-weighted images (CTV2) plus 3-mm margin for geometric uncertainty. Dose delivered was 25 Gy/5 fr to PTV1 and 20 Gy/5 fr to PTV2, dose was prescribed at 70% isodose surface with internal dose gradient of about 30% and the hot-spot was localized on the eventual residual disease. Treatment planning was obtained by inverse planning module (Eclipse Varian). Four weeks after radiotherapy, treatment with temozolomide was started (200 mg/m2; for 5 days every 4 weeks) and administered until disease progression. Results: Out of 30 patients, 28 were evaluated for outcome (two refused temozolomide). No G3 radiation toxicities were observed and hematologic toxicity with temozolomide G3 was reported in only 3 patients. Median survival was 14 months (range 4–48) and global survival at 1 and 2 years was respectively 53% and 30%. Conclusion: Hypofractionated radiotherapy with IMAT technique and sequential temozolomide is safe and well tolerated. Toxicities and survival results, median and at 2 years, in agreement with literature data, suggest that hypofractionated radiotherapy could represent an alternative to standard treatment. Furthermore it is shorter then traditional treatment (60 Gy in 30 fr) and may improve patients, quality of life. Obviously, further studies are needed to compare this technique with standard treatment modalities. O40. PROSPECTIVE RANDOMIZED STUDY COMPARING FIRST-LINE NITROSOUREA-BASED CHEMOTHERAPY VERSUS RADIOTHERAPY ALONE IN NONRESECTABLE GLIOBLASTOMAS IN ADULTS M. Frenay1, J. Simon2, L. Benboubker3, L. Taillandier4, D. Castera5, M. Campone6, A. Busson7, F. Berger8, C. Lebrun9; 1CAL, Nice, France, 2Hopital Salpetriere, Paris, France, 3Hopital Bretonneau, Tours, France, 4Hopital Central, Nancy, France, 5Clinique St Pierre, Perpignan, France, 6Centre Gauducheau, Saint Herblain, France, 7Centre Baclesse, Caen, France, 8Chu Grenoble, Grenoble, France, 9CHU, Nice, France Objective: To compare time to progression in patients with non resectable glioblastomas (GBL) treated with either radiotherapy (RT) or a nitrosourea based chemotherapy (CT) with platinium salts. Patients and Methods: Phase III multicentric prospective randomized study comparing time to progression (TTP) in patients diagnosed for GBL confirmed with histological diagnosis according to WHO classification. All patients had nonresectable tumor because of location or callosal extension. CT (F/CDDP/VP16) consisted of 4 monthly cycles of fotemustine (100 mg/m2, d1), cisplatinium (33 mg/m2/d, d1–3), etoposide (75 mg/m2/d1–3) followed by conventional fractionated radiotherapy (55–60 Gy). MRI was performed at baseline before and after surgery and every 8 weeks. Clinical and QOL evaluation was monthly reported. Results: 50 patients were randomized (26 CT-RT and 24 RT alone) with mean age: 58 yrs (33–71); mean Karnofsky score: 86.4 +/- 11; mean time between biopsy and NU-CT or RT was less than 6 weeks. 70% (35/50) had only stereotaxic biopsy and others had partial resection. Time to progression was 242 days (IC95: 99–314) for CT-RT versus 131 d (IC95: 92–208) for RT alone; p=0.0085. Median survival was 375.5 d (IC95: 323–427) for CT-RT vs. 325 (IC95: 200–504) p=0.36 for RT alone. The best tumoral response was 23% for CT-RT vs. 8% with RT. Patients had the following grade III or IV side effects: CT-RT, 62% hematological toxicity; RT, 17% neurological toxicity. Nine patients died during the follow-up (6 tumor progression, 2 sepsis, 1 unknown). Conclusions: Time to progression and median survival are increased with the association CT followed by brain RT. O41. PHASE I/II STUDY OF ENZASTAURIN (ENZ) PLUS TEMOZOLOMIDE (TMZ) AND RADIATION THERAPY (XRT) IN PATIENTS (PTS) WITH GLIOBLASTOMA MULTIFORME (GBM) OR GLIOSARCOMA (GS) N. Butowski1, K. Lamborn1, S. Chang1, M. Page1, R. Parvataneni1, S. Chang2, A. M. Liepa2, S. Nicol2, D. Thornton2, M. Prados1; 1University of California, San Francisco, San Francisco, CA, United States, 2Eli Lilly and Company, Indianapolis, IN, United States Background: ENZ, an oral serine/threonine kinase inhibitor, suppresses signaling through PKCβ and the PI3K/AKT pathways to induce apoptosis, reduce cell proliferation, and suppress angiogenesis. PKCβ is activated by vascular endothelial growth factor, an angiogenic factor upregulated in most GBM. Phase I assessed maximum tolerated dose of ENZ given concurrently with RT plus TMZ and then adjuvantly with TMZ in pts with GBM/GS to define a phase II ENZ dose. Phase I secondary objectives assessed safety, pharmacokinetics, antitumor activity, pharmacogenomics, quality of life (QoL), and utility of magnetic resonance perfusion imaging. The phase II primary objective was overall survival, and secondary objectives continued most phase I endpoints plus progression-free survival. Methods: Pts with newly diagnosed GBM/GS and KPS ⩾60 were enrolled. Enzyme-inducing antiepileptic drugs were not permitted. Treatment began <5 weeks after diagnosis with RT 60 Gy given over 6 weeks with TMZ 75 mg/m2 given daily during RT and then adjuvantly at 200 mg/m2, from days 1–5 of a 28-day cycle. ENZ was given orally, once daily, during RT at a starting dose of 250 mg/day (cohort 1) and continued at the same dose in the adjuvant setting. ENZ was escalated to 500 mg/day (cohort 2), if, during RT and the first adjuvant cycle of TMZ, no more than 1/6 pts had a dose limiting toxicity (DLT). DLTs were ges;G3 thrombocytopenia (Tp), G4 anemia/neutropenia, or ges;G3 nonhematologic toxicity. Planned duration of adjuvant TMZ/ENZ therapy was 12 cycles. QoL was assessed using FACT-Br and MDASI-BT. Results: From 9/06–6/07, 12 pts enrolled in Phase I. There were no DLTs in the 6 pts of cohort 1. One pt withdrew and later progressed. As of 2/1/08, 5 pts in cohort 1 continue on ENZ 250 mg/day at ⩾14 cycles. In cohort 2, 2/6 pts experienced a DLT; one G4 and one G3 Tp. One pt recovered to ⩽G1 in <28 days and reinitiated adjuvant TMZ and reduced-dose ENZ. The other pt recovered to ⩽G1 after 28 days, but discontinued. Three pts discontinued due to progressive disease, and one pt continues on ENZ 500 mg/day. Phase II began accrual in 9/07. Conclusions: ENZ 250 mg/day with RT+TMZ was well tolerated and is the recommended phase II dose. In addition to phase I, available phase II, and QoL data, we shall present preliminary pharmacogenomic results evaluating the predictive value of potential ENZ molecular targets on treatment outcomes as well as initial results with the use of physiological imaging for pt evaluations. O42. RADIOCHEMOTHERAPY WITH DAILY CONCOMITANT AND ADJUVANT ONE WEEK ON/ONE WEEK OFF TEMOZOLOMIDE PLUS INDOMETHACIN IN NEWLY DIAGNOSED GLIOBLASTOMA: A PHASE II TRIAL M. Weiler1, C. Hartmann2, D. Wiewrodt3, U. Herrlinger4, M. Bamberg5, A. von Deimling1, M. Weller6, W. Wick1; 1University of Heidelberg, Heidelberg, Germany, 2German Cancer Research Center, Heidelberg, Germany, 3University of Mainz, Mainz, Germany, 4University of Bonn, Bonn, Germany, 5University of Tübingen, Tübingen, Germany, 6University of Zurich, Zurich, Switzerland Background: To evaluate toxicity and efficacy of an intensified schedule of temozolomide plus indomethacin in addition to standard radiotherapy plus concomitant temozolomide in patients with newly diagnosed glioblastoma. Methods: This trial (UKT-05) enrolled 41 patients treated with preirradiation temozolomide at 150 mg/m2 (one week on/one week off), radiotherapy with concomitant temozolomide (50 mg/m2), maintenance temozolomide starting at 150 mg/m2 according to an intensified one week on/one week off schedule, and maintenance indomethacin (25 mg bid) treatment. The primary endpoint was median progression-free survival (PFS). O6-methylguanine-DNA methyltransferase (MGMT) gene promoter methylation was assessed by methylation-specific PCR in 39 (95.1%) patients. Results: The median follow-up interval is 15.3 months (minimum, 9.4 months). Hematologic grade 3/4 toxicities according to the Common Terminology Criteria for Adverse Events (CTCAE; v3.0) were: anemia (3/41, 7%), leukopenia (9/41, 22%), lymphopenia (26/41, 63%), neutropenia (6/41, 15%), and thrombopenia (8/41, 20%). Treatment-related nonhematologic CTCAE grade 3 through 5 toxicities were reported for n=6/41 (15%) patients. Median PFS was 7.6 months [95% CI, 6.2–10.4 months]. PFS rate at 6 months (PFS-6) was 70.7% [95% CI, 54.3–82.2%]. The censored one year survival rate was estimated at 71.8% [95% CI, 54.7–83.4%]. Median PFS, PFS-6 and median survival time (MST) in 16 patients with MGMT gene promoter methylation were significantly larger than in 23 patients without epigenetic MGMT gene silencing (median PFS: 15.8 vs. 6.2 months, P=0.001; PFS-6: 81.3% vs. 65.2%; MST: 24.1+ vs. 12.9+ months, P=0.027). Conclusions: The dose-intensified regimen of temozolomide administered in a one week on/one week off schedule resulted in relevant but acceptable toxicity. Compared with data from the EORTC/NCIC trial 26981–22981/CE.3, patients with an unmethylated MGMT gene promoter in the tumor did not appear to benefit from intensifying the temozolomide schedule regarding median PFS or MST whereas the efficacy in the methylated cohort looks very promising. At the time of EANO, updated results and survival estimates after a minimum follow-up of at least 15 months will be available. O43. THE TOPOGRAPHY OF CELLULAR MALIGNANCY IN HUMAN GLIOBLASTOMA M. Glas1*, B. H. Ley2, A. Leinhaas2, R. Eisenreich3, B. Steinfarz2Δ, J. Schramm4, M. Simon4, U. Herrlinger5, O. Brüstle2, B. Scheffler3; 1Clinical Neurooncology Unit and Insitute for Reconstructive Neurobiology, Stem Cell Pathologies Group, University of Bonn, Bonn, Germany, 2Insitute for Reconstructive Neurobiology, University of Bonn, Bonn, Germany, 3Insitute for Reconstructive Neurobiology, Stem Cell Pathologies Group, University of Bonn, Bonn, Germany, 4Dept. of Neurosurgery, University of Bonn, Bonn, Germany, 5Clinical Neurooncology Unit, University of Bonn, Bonn, Germany The major driving force of mortality in human glioblastoma (GBM) is in most cases the recurrence of tumor growth, likely caused by a heterogeneous population of rapidly dividing tumor cells that exhibit hitherto unrecognized resistance mechanisms to standard therapy. To assess the heterogeneous nature of GBM tissue, we have isolated and characterized paired biopsy samples from a total of 26 patients in direct comparison. In each case, the samples derived from distinct regions of the tumor mass and microscopic evaluation revealed dissimilar histological characteristics. For controlled analysis, we used defined in vitro conditions for the isolation and the expansion of cells from these paired biopsy samples. Our data indicate a distinct topography of the key features of cellular malignancy, i.e., the content of stem cells, and the respective migratory and proliferative potential of cells vary significantly between individual tumor regions. Because FACS and qPCR analysis furthermore revealed a regionally confined expression profile of therapeutically relevant surface antigens, we would like to suggest that the investigation of cells from different tumor regions should necessarily be considered for future diagnosis and treatment of GBM. *MG was supported by the BONFOR program of the University of Bonn Med Ctr. ΔBS is supported by the VW Foundation. O44. IDENTIFICATION OF RELEVANT MARKERS FOR THE CLASSIFICATION AND GRADING OF DIFFUSELY INFILTRATIVE GLIOMAS Y. Ruano1, T. Ribalta2, A. Rodríguez de Lope1, C. Fiaño3, E. Pérez-Magán1, J. Hernández-Moneo1, Y. Campos-Martín1, J. García4, M. Mollejo1, B. Meléndez1; 1Hospital Virgen de la Salud, Toledo, Spain, 2Hospital Clinic, Barcelona, Spain, 3Complejo Hospitalario Xeral-Cíes, Vigo, Spain, 4MD Anderson Internacional, Madrid, Spain Diffusely infiltrative gliomas can be histopathologically classified as astrocytic tumors, pure oligodendroglial tumors, and mixed oligoastrocytic tumors. However, the classification and grading of these tumors can be usually difficult. The knowledge of the molecular genetic background of gliomas is helpful in classifying diffuse gliomas with regard to prognosis and response to chemotherapy. In particular, loss of heterozygosity on chromosome arms 1p and 19q is a frequent event in oligodendroglial tumors, significantly correlated with better prognosis and chemosensitivity. In this work, we aimed to identify molecular markers helpful in the diagnosis and grading of gliomas. For this purpose, we performed expression profiling analyses in 37 gliomas: 19 oligodendrogliomas (OG), 9 mixed oligoastrocytomas (OA), and 9 astrocytomas (AC). Functional analyses were carried out by using GEPAS (CIPF, Valencia, Spain) and GSEA (Broad Institute, Massachusetts, Cambridge). A comparative analysis of tumors of WHO grades II and III revealed that genes significantly up-regulated in grade III were involved in cell cycle, cell proliferation, and metabolism processes. Likewise, comparision of the gene expression profiles of OG, OA, and AC subtypes showed that mixed oligoastrocytomas presented gene expression patterns more similar to astrocytomas than to oligodendrogliomas. Significant up-regulation of CD44, C4B, or ANXA1 were detected in astrocytomas and mixed oligoastrocytomas, while they were underexpressed in oligodendrogliomas. Our findings support the molecular relevance of the astrocytic component in oligoastrocytomas and propose a set of candidate genes which may be useful for the differential diagnosis of gliomas and tumor grading. O45. CONVERSION OF ASTROCYTES INTO PROGENITOR-LIKE CELLS UPON TRANSFORMING GROWTH FACTOR ALPHA (TGF-ALPHA) EXPOSURE SENSITIZES THEM TO CANCEROUS TRANSFORMATION C. Dufour1, J. Cadusseau2, P. Varlet1, N. Auger1, E. Daudigeos1, P. Rodier1, A. Dias-Morais3, G. Vassal1, H. Chneiweiss3, M. Junier4; 1Gustave Roussy, Villejuif, France, 2Inserm U841, Créteil, France, 3Inserm UMR 894, Paris, France, 4Hospital Sainte-Anne, Paris, France Astrocytes may give raise to glioma, the most frequent primitive CNS tumors. TGF-alpha, an EGF family member, is trophic for both astrocytes and gliomas cells, but its sole deregulation is insufficient to lead to cancerous transformation of astrocytes. It however triggers their conversion into neural progenitor-like cells capable to give birth to neurons (Sharif et al, Oncogene, 2007). Neural progenitors have been reported to be more sensitive than astrocytes to oncogenic manipulations in transgenic mice. These data, and the frequent overexpression of TGF-alpha in early steps of gliomas progression, led us to envisage a participation of this factor to tumor genesis through the destabilization of the mature astrocyte phenotype. Irradiation, a classic mutagen, was used to determine whether astrocytes converted into neural progenitor-like cells are more sensitive than their mature counterpart to cancerous transformation. Mouse astrocyte cultures were maintained 7 days in serum-free medium without (control) or with TGF-alpha (50 ng/ml), prior to be either sham-irradiated or irradiated (137Cesium source, 5 Grays once fraction). Control cultures survived 2 weeks post sham-irradiation or irradiation. On the opposite, TGF-alpha-treated astrocytes were immortalized upon irradiation. Their cancerous transformation was ascertained by their ability to form colonies in methylcellulose medium, their karyotype anomalies, and the formation of sub-cutaneous tumors in NOD-SCID mice and high-grade glioma-like tumors after grafting into nude mice CNS. Sham-irradiated cells failed to show any evidence of transformation. These results demonstrate that instability of the mature astrocyte phenotype due to a single epigenetic change is sufficient to sensitize them to cancerous transformation. They allow proposing that TGF-alpha does not only favor growth and survival of established gliomas but participates also to the earliest stages of their genesis. O46. THE RESPONSE OF HUMAN GLIOMA CELLS TO TEMOZOLOMIDE AND IRRADIATION: RELATIONSHIP WITH MGMT PROMOTOR METHYLATION AND PROTEIN EXPRESSION P. Sminia1, K. A. van Nifterik1, J. van den Berg1, N. Ameziane1, T. J. M. Hulsebos2, S. Leenstra2, L. Wedekind1, M. V. M. Lafleur1, L. J. A. Stalpers2, B. J. Slotman1; 1VU University Medical Center, Amsterdam, The Netherlands, 2Academic Medical Center, Amsterdam, The Netherlands Purpose: Investigation of the effect of temozolomide (TMZ) alone or combined with irradiation in human glioblastoma multiforme (GBM) cell lines. Methods and Materials: A panel of four established (U251, D384, TG98 and HS682) and seven long term primary GBM cell lines were analyzed for the promotor methylation status of the methylguanine-DNA methyltransferase (MGMT) gene by a methylation specific multiplex ligation-dependent probe amplification assay. MGMT protein expression was studied by Western blotting. TMZ sensitivity of the cells was tested in a clonogenic assay by single exposure to TMZ (0–500 μM) for 24 h. Three cell lines that were sensitive to TMZ in the clinically feasible dose range were selected for combined treatment with irradiation. Cells were irradiated with five daily 2 Gy fractions with TMZ (3–10 μM) administered 1 h prior to each irradiation fraction. Treatment response was evaluated on cell proliferation and by clonogenic assays. Results: TMZ sensitivity was highly variable between the GBM cell lines: four of the eleven GBM cell lines expressed the MGMT protein and were TMZ resistant. The other seven cell lines had absent or diminished MGMT protein expression and were TMZ sensitive: the fraction of surviving clonogenic cells was reduced to <0.5 after 24 h exposure to <50 μM TMZ. The TMZ sensitivity correlated with an absent expression of the MGMT protein. However, no correlation was found between the sensitivity of cells to TMZ and the MGMT promotor methylation status. Two out of four partly MGMT promotor methylated cell lines still showed expression of the protein. In the combination experiments with fractionated irradiation and concomitant TMZ, one out of three (TMZ sensitive) cell lines showed a radiosensitizing effect of TMZ. Conclusions: Expression of the MGMT protein, more than the MGMT-promotor methylation status, predicts the sensitivity of human glioma cells to TMZ. The effect of TMZ is additive to irradiation, but not necessarily synergistic. Neither the MGMT promotor methylation status, nor the absence of the protein predicts for the radiosensitizing effect of TMZ. Supported by the Dutch Cancer Society project #VU 2000-2149. O47. TEMOZOLOMIDE INDUCES SELECTIVE DEPLETION OF CANCER STEM CELLS IN HUMAN GLIOBLASTOMAS D. Beier1, S. Röhrl1, D. R. Pillai1, S. Schwarz1, L. Kunz-Schughart2, M. Proescholdt3, A. Brawanski3, U. Bogdahn1, J. Wischhusen4, G. Reifenberger5, P. Hau1, C. P. Beier1; 1Department of Neurology, Regensburg, Germany, 2ZIK, OnkoRay, Dresden, Germany, 3Department of Neurosurgery, Regensburg, Germany, 4Interdisciplinary Center for Clinical Research, Würzburg, Germany, 5Department of Neuropathology, Düsseldorf, Germany Glioblastomas (GBM) are among the most aggressive human cancers with a median survival of 14.6 months despite multimodal therapy. Although today's standard of care—temozolomide—significantly increases the proportion of patients surviving for more than two years, long-term survivors are still a rare exception. The biological properties of cancer stem cells (CSC) maintaining GBM provide a possible explanation for the failure of chemotherapy in the long term: CSC from several tumor entities overexpress multidrug resistance proteins which may protect them against cytotoxic drugs that kill progenitor and differentiated cells. CSC would then give rise to recurrent tumors. However, although multiple authors have postulated this model, it has not yet been convincingly confirmed experimentally for GBM. We therefore investigated the effect of temozolomide on CD133+ and CD133- CSC lines (n=5) using an established in vitro model of GBM stem cell lines. Surprisingly, temozolomide induced a dose- and time-dependent decline of the rapidly proliferating stem cell subpopulation while differentiated tumor cells constituting the bulk of all tumor cells were resistant to the cytotoxic effects of the substance. Incubation with sublethal concentrations of temozolomide for 2 days eliminated clonogenic tumor cell growth in vitro and reduced the tumorigenicity in vivo. The susceptibility of CSC to temozolomide was meditated by O6-methylguanine-DNA-methyltransferase (MGMT), the MGMT promoter methylation status did not differ between CSC and differentiated tumor cells. MGMT-expressing CSC showed a 10 fold higher resistance to temozolomide which was reversible by the MGMT inhibitor 6-benzylguanidin. Despite the selective elimination of CSC in GBM, we found that CSC in all stem cell lines investigated were completely resistant toward the cytotoxic effects of 5 μM temozolomide, which corresponds to the peak concentration measured in the cerebrospinal fluid of patients. While concentrations required to eliminate MGMT positive CSC (500 μM) can not be reached in the patient, concentrations up to 50 μM have been measured in the plasma of patients after standard treatment and sufficed to eliminate CSC in MGMT negative tumors. While these findings explain the poor outcome of MGMT positive tumors, it is unclear why patients with MGMT negative tumors die despite the susceptibility of CSC to temozolomide. Considering the impaired blood-brain barrier in the tumor and infiltration of CSC in otherwise healthy brain tissue with much lower temozolomide concentrations, we postulate that recurrent GBM in MGMT negative tumor derive from invading CSC protected against temozolomide by the intact blood-brain barrier. Together, this study will fundamentally change the understanding of CSC and bears important implications for the conception and interpretation of future and past clinical trials. O48. CONCORDANCE BETWEEN SERUM DNA AND TUMOR DNA IN DETECTION OF GENETIC-EPIGENETIC ABERRATIONS OF GLIAL TUMORS I. Lavon, M. Raphael, J. Goldmann, B. Zelikovitch, T. Siegal; Hadassah Hebrew University Hospital, Jerusalem, Israel Background: Genetic and epigenetic aberrations, like loss of chromosomal heterozygosity (LOH) and hypermethylation of gene promoters, are frequently observed in glial tumors. Detection of these aberrations, which is performed on tumor DNA, carries a potential diagnostic and prognostic relevance. As sample materials for diagnosis should be easily accessible by a minimally invasive procedure, there has been much interest in the potential use of nucleic acid markers in the blood of patients with cancer. Objective: To find whether genetic aberrations in serum DNA of glial tumors can be detected at a time distant from surgical intervention and to evaluate its concordance with tumor DNA. Methods: DNA was extracted from the serum and the paraffin embedded tumor sections of 35 patients with GBM and 23 patients with oligodendrogliomas (18 grade II; 5 grade III). The methylation status of O(6) methylguanine-methyl-transferase (MGMT) promoter and chromosomal 10q LOH were evaluated in DNA samples obtained from both the serum and tumor sections. Results: In GBM, the incidence of MGMT promoter methylation was 43% in the tumor and 31% in serum while 10q LOH was found in 64% of tissue samples and 43% of serum DNA. In oligodendrogliomas, the incidence of MGMT promoter methylation was 70% in the tissue and only 17% in serum. The concordance between the results obtained from tumor DNA and serum DNA for both MGMT methylation status and 10q LOH was 71% for GBM. In oligodendrogliomas the concordance of the results for MGMT was 48%. Conclusions: These results imply that serum DNA, which is obtained at various times following tissue diagnosis or initial treatment, often represents the tumor DNA. The concordance between serum and tumor DNA is better for GBM than for oligodendrogliomas. It is possible that higher proportion of GBM patients had an active tumor at time of serum sampling as compared to patients treated for oligodendrogliomas. It cannot be excluded that high-grade tumors shed more DNA into the bloodstream, explaining the better concordance observed in GBM. We are currently correlating results of paired serum-tumor samples with clinical and imaging details of each patient. In addition, we are in the process of comparing the rate of detection of genetic aberration following extraction of serum DNA by two different techniques in order to refine the methodology. These results will be presented at the conference. O49. INCREASED RISK OF STROKE AND TRANSIENT ISCHEMIC ATTACK (TIA) IN 5-YEAR SURVIVORS OF HODGKIN'S LYMPHOMA L. D. Dorresteijn1, M. L. De Bruin2, M. B. van 't Veer3, E. M. Noordijk4, H. van den Berg5, B. M. Aleman2, A. C. Kappelle1, W. Boogerd2, F. E. van Leeuwen2; 1Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands, 2Netherlands Cancer Institute, Amsterdam, The Netherlands, 3Erasmus MC/Daniel den Hoed Center, Rotterdam, The Netherlands, 4Leiden University Medical Center, Leiden, The Netherlands, 5Emma Children's Hospital, Amsterdam, The Netherlands Background: The incidence of self-reported stroke in survivors of childhood Hodgkin's lymphoma (HL) is increased compared to their siblings. It is not clear whether the increased risk is also present in adults and when analyses are restricted to clinically verified strokes and transient ischaemic attacks (TIAs). Methods: We performed a cohort study among 2,202 5-year survivors treated for HL in the period 1965–1995 before age 51. We compared the incidence of stroke and TIA with the general population and calculated standardized incidence ratios (SIRs) and absolute excess risks (AERs per 10,000 patients per year) for different age, treatment, and sex strata. Results: During follow-up (median 17.8 years), 61 (SIR 1.9 [1.5–2.4], AER 9) and 47 (SIR 3.4 [2.5–4.5]) patients developed stroke and TIA, respectively. Nine strokes (SIR 4.0 [1.8–7.6], AER 8) and seven TIA (SIR 10.0 [4.0–20.6], AER 8) occurred among patients treated for HL before age 21. SIRs were increased among those treated with radiotherapy (RT) alone (especially neck RT), or with RT+chemotherapy (CT). Females experienced higher risks than males, especially those treated before age 21. The 30-year cumulative risk of CVA was 10.6%. Conclusion: Survivors of HL are at increased risk for clinically verified stroke and TIA. The risks are treatment and gender related and substantially higher among childhood and adolescent HL survivors compared to adults. O50. OPTIC NEUROPATHY IN PATIENTS WITH MALIGNANT GLIOMAS TREATED WITH BEVACIZUMAB J. H. Sherman1, D. G. Aregawi1, A. Lai2, S. S. Rosenfeld3, H. M. Fathallah-Shaykh4, J. M. Larner1, S. A. Newman1, D. Schiff1; 1University of Virginia, Charlottesville, VA, United States, 2University of California, Los Angeles, Los Angeles, CA, United States, 3Columbia University, New York, NY, United States, 4Rush University, Chicago, IL, United States Introduction: Bevacizumab, a monoclonal antibody targeting vascular endothelial growth factor, has recently been studied for both initial treatment and recurrence of malignant gliomas. Initial data indicate that patients show an increased response rate as well as an increase in progression free survival as compared to historical controls. Despite this promising data, isolated reports have emerged of acute optic neuropathy in a small subset of patients with malignant gliomas treated with bevacizumab. Methods: Using the clinical records from 2005 to 2008, we identified adult patients with glioblastoma treated with bevacizumab who developed acute optic neuropathy. Four institutions participated in this study including the University of Virginia, UCLA, Columbia University, and Rush University. Age at diagnosis, gender, radiation therapy data, the chemotherapeutic regimen including the bevacizumab dosing schedule, ophthalmologic records, laboratory values, and MR imaging were assessed. Results: Five patients were identified, including one male and four females. Mean age at diagnosis was 54 years (range 37 to 68). Following surgical resection of a glioblastoma all patients received fractionated radiation therapy with concomitant temozolomide. One patient received bevacizumab at initial diagnosis, while the other four received the drug at recurrence. The mean radiation dose to the optic chiasm, left optic nerve, and right optic nerve was 5,509.7 cGy, 4,344.3 cGy, and 3,679.8 cGy, respectively. The mean time from the end of radiation therapy to the onset of visual symptoms was 11.5 months (range 8 to 15.5). The patients completed a mean of 10.4 doses (range 3 to 18) of bevacizumab prior to onset of visual symptoms. Visual loss subsequently developed unilaterally in three patients and bilaterally in two patients. MR imaging from one of the former patients displayed left optic nerve enhancement while another patient displayed parenchymal gliomatosis. MR imaging from one of the latter patients displayed bilateral optic nerve enhancement as well as evidence of parenchymal gliomatosis. Post-mortem pathologic specimen of the patient with left optic nerve enhancement displayed no evidence of tumor infiltration. CSF analysis was performed in four patients and showed no evidence of demyelinating disease or meningeal gliomatosis. The mean time from visual symptom onset to no light perception in at least one eye was 1.7 months (range 0.5 months to 4.5 months). Conclusions: A small subset of glioblastoma patients treated with standard chemoradiation therapy has developed optic nerve dysfunction following treatment with bevacizumab. Patients receiving bevacizumab should be followed closely in order to clarify whether this complication represents drug-related optic neuropathy, coincidental radiation optic neuropathy, or an unusual bevacizumab-related pattern of tumor failure. O51. COMPARISON OF THE RETROSPECTIVE AND PROSPECTIVE BSBM SYSTEM'S CLASSIFICATION WITH A 6 YEAR FOLLOW UP FOR PATIENTS WITH BRAIN METASTASES TREATED BY LEKSELL GAMMA KNIFE RADIOSURGERY D. Devriendt1,2, F. De Smedt1, P. David3, N. Massager4; 1Institut Jules bordet, Brussels, Belgium, 2Gamma Knife Center of ULB, Brussels, Belgium, 3Erasme Hospital, Brussels, Belgium, 4Gamma Knife Center of ULB, Brussels, Belgium Objective: We proposed a few years ago a new system classification called Basic Score for Brain Metastases (BSBM) built on a retrospective study concerning patients with brain metastases (BM) treated by radiosurgery. The three significant prognostic factors were (i) a Karnosky Performance Status (KPS) equal or superior to 80 (no = 0; yes = 1 point), (ii) an absence of a systemic disease (no = 0; yes = 1 point), and (iii) a primary disease controlled (no = 0; yes = 1 point). This classification varied from 0 to 3 points. Since January 2003, we followed prospectively the new cohort of patients. This study analyzed the survival of both (retrospective and prospective) populations. Material and Methods: 267 evaluable patients with more than 700 brain metastases were treated with a Leksell Gamma Knife model C. Median marginal dose was 20 Gy at a median 50% isodose. There were 45% (119 pts) lung cancer, 22% (59 pts) breast cancer, 19% (49 pts) melanoma, and 15% (40 pts) other primary tumors. The retrospective study concerned 110 patients (102 dead = 92%) treated from December 1999 to December 2002. The prospective study concerned 157 patients (95 dead = 61%) treated from January 2003 to December 2005. Results: median survival (MS) for the entire population is 11 months and 3, 6, 12, and 23 months for respectively BSBM 0, 1, 2, and 3 points subgroups. For the selective categories BSBM 0, 1, 2, and 3 points, the MS were respectively 3, 3.5, 11, and 20 months for the retrospective study versus 3.5, 7, 13, and 27 months for the prospective study. The multivariate analysis identifies as significant factors: the KPS, the SIR and the BSBM models. On the validation set, the discrimination power of the BSBM score assessed by the area under the ROC curve. The difference between the retrospective and the prospective subgroups is not statistically different. Conclusions: The BSBM system's classification is comparable in the retrospective and prospective studies suggesting the value of this new original classification. O52. IMPACT OF SURGICAL EXCISION METHODOLOGY ON THE INCIDENCE OF LOCAL RECURRENCE IN PATIENTS WITH SINGLE BRAIN METASTASIS (SBM) WHO HAVE NOT RECEIVED ADJUVANT WHOLE BRAIN RADIATION THERAPY (AWBRT) D. Suki1, A. J. Patel2, M. A. Hatiboglu1, H. Abou-Assi1, R. Sawaya1; 1M.D. Anderson Cancer Center, Houston, TX, United States, 2Baylor College of Medicine, Houston, TX, United States Background: We previously reported that piecemeal resection (PMR) of a posterior fossa or supratentorial brain metastasis increased the risk of LMD development compared to enbloc resection (EBR). In this study, we assess the association between resection methodology and local recurrence in patients with a previously untreated SBM and no AWBRT. Methods: An institutional review board approved data review was performed. This report summarizes data from 570 patients with an SBM treated at M.D. Anderson between June 1993 and December 2006 identified from the prospectively compiled Brain and Spine Center Database. The primary outcome was incidence of recurrence at the resected site (local recurrence). Of note, in most cases, the method of resection was prospectively noted by the neurosurgeons and entered into the database at the time of the procedure. In determining the incidence of local recurrence, patients were censored at the time of WBRT; a biopsy, resection, or stereotactic radiosurgery to the index site after the index procedure, whichever occurred first. The Cox proportional hazards method was used to assess local recurrence following PMR and EBR. Results: The median patient age was 58 years; 55% were males; 95% had a Karnofsky score >70. The most common primary type was lung (28%), melanoma (21%), renal (19%), and breast (10%). PMR was performed in 202 patients (35%) and EBR in 368 (65%). The two groups were comparable with respect to gender, age at surgery, KPS score, and tumor location with respect to eloquent grade. They were also comparable with respect to status of systemic cancer and primary cancer type, except that PMR was used significantly more often in patients with renal cell carcinoma. Tumors resected following the PM approach were significantly larger (median volume 15.8 cc versus 7.6 cc in the group resected following the EB approach). Local recurrence was observed in 84 patients (15%). In preliminary analyses, undergoing PMR resection carried a significantly higher local recurrence risk than EBR [hazard ratio (HR) for PM=1.7; 95% confidence interval (CI), 1.1–2.6; p=0.03]. The effect of method of resection in patients with different prognostic characteristics is being assessed. Conclusion: In preliminary analyses, there was an increased risk of local recurrence with piecemeal resection of a SBM compared to EBR in patients not treated with adjuvant whole brain radiation. Piecemeal resection was previously found to be independently associated with an increased risk of LMD in patients with posterior fossa and supratentorial metastasis at our center. Prophylactic measures such as early institution of AWBRT may be warranted in some situations in which PMR of the tumor is unavoidable. O53. DIFFERENTIAL IMPACT OF WHOLE BRAIN RADIOTHERAPY ADDED TO RADIOSURGERY FOR THE RPA CLASS I OR II BRAIN METASTASES D. Kong, J. Lee, Y. Im, D. Nam, K. Park, J. Kim; Department of Neurosurgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea Background: The authors investigated outcome of stereotactic radiosurgery (SRS) alone for the patients with brain metastases, compared with SRS plus whole-brain radiotherapy (WBRT). Methods: 261 patients with 1 to 10 metastatic lesions were retrospectively analyzed. 180 patients were treated with SRS alone (marginal dose 13–26 Gr), and 81 patients received SRS (marginal dose 12–19 Gy) plus WBRT (30 Gy). Actuarial curves were estimated using the Kaplan-Meier method regarding overall survival (OS), distant brain control (DC), and local brain control (LC) stratified by RPA class. Analyses for known prognostic factors including age, sex, performance status, primary tumor origin, number of brain metastases, extracranial metastases, treatment modality, and RPA class were performed using the Cox proportional hazards model. Results: In RPA class 1, survival time with SRS plus WBRT was significantly longer than SRS alone (390 vs. 931 days, p = 0.017). However, in RPA class 2, no significance in OS was observed between SRS alone and SRS plus WBRT (275 vs. 346 days, p = 0.311). In RPA class 1, DC was higher in SRS plus WBRT group (p = 0.047), while there was no difference in LC between two groups (p = 0.718). However, in RPA classes 2, DC and LC revealed no difference between two groups. Conclusions: For the patients in RPA class 1, SRS plus WBRT appeared to be more effective than SRS alone, whereas addition of WBRT did not have significant impact on survival, DC, and LC in class 2. The result suggests that SRS alone may be recommended for the patients with limited life expectancy due to extracranial disease and addition of WBRT for the patients in whom long term survival is expected based on extracranial disease status. O54. PHASE II TRIAL OF PATUPILONE IN PATIENTS WITH BREAST CANCER BRAIN METASTASES D. M. Peereboom1, A. K. Conlin2, A. D. Seidman2, C. Brewer1; 1Cleveland Clinic, Cleveland, OH, United States, 2Memorial Sloan Kettering Cancer Center, New York, NY, United States Introduction: Brain metastases from breast cancer (BCBM) have become more prevalent with improved systemic therapies for this malignancy. As a result, recurrent brain metastases after whole brain radiation therapy (WBRT) are becoming more common. Patupilone is an epothilone which crosses the blood brain barrier and is many-fold more potent than paclitaxel or docetaxel. This agent has activity against systemic breast cancer as well as brain metastases from non–small cell lung cancer. This trial evaluates patupilone in patients with BCBM. Methods: This multicenter, phase II study will enroll 45 pts with progressive, measurable BCBM after WBRT with an exploratory group of 10 additional pts with leptomeningeal disease or asymptomatic, unirradiated brain metastases. Patients may continue trastuzumab and hormonal therapy but no other chemotherapy. Patients must be at least 4 weeks past WBRT, 3 weeks past cytotoxic therapy (6 weeks for nitrosoureas), 2 weeks past noncytotoxic agents, and on a stable dose of steroids. Exclusions are prior treatment with epothilones and NCI CTC grade > 1 diarrhea or neuropathy. Patients receive patupilone 10 mg/m2 i.v. over 20 minutes every 3 weeks with MRI brain and CT chest/abdomen every 6 weeks. The primary endpoint is 3-month central nervous system (CNS) progression free survival (PFS). Secondary endpoints include toxicity, systemic disease response rate, and overall survival. Results: 18 pts have enrolled since February 2007 including 14 in the primary study group. The median age is 55 (43–68 yrs). All have had prior chemotherapy: 94% taxanes and 71% anthracyclines. Baseline KPS is 60–70 in 28% (5 pts) and 80–100 in 72% (13 pts). Toxicity data are available for 17 pts. The most common toxicity has been diarrhea—grade 1: 8 pts (47%); grade 2: 4 pts (24%) and grade 3: 5 pts (29%). Four grade 4 events (hypokalemia [2], upper GI bleeding, and anemia) have occurred. Three pts have had 25% dose reductions (myalgia, diarrhea/hypokalemia, and GI ulcer). Three patients have died, 1 possibly related to therapy. To date, best responses have been 3 partial responses (1 confirmed), 3 stable disease, 9 progressive disease, and 1 too early. One pt withdrew before assessment, and 1 pt died before assessment. The 3-month PFS in the CNS is 3/18 (17%). One pt suspected of radiographic progression on MRI underwent resection and had only necrotic tissue without viable tumor. Conclusions: Patupilone has activity against recurrent breast cancer brain metastases. The three-month CNS progression-free survival is 17%. Toxicity is acceptable in this heavily pretreated patient population. The finding of necrosis in one patient with apparent radiographic progression suggests the need for careful evaluation of previously irradiated lesions in patients treated with chemotherapy for BCBM. The role for agents like patupilone will be come more important as the ability to control systemic disease improves O55. MOLECULAR STEREOTACTIC BIOPSIES IN GLIOMAS —A PROSPECTIVE ONE-YEAR EXPERIENCE C. A. Eroes1, N. Thon1, E. Grasbon-Frodl2, G. Poepperl3, J. Tonn1, F. Kreth1; 1Klinikum Grosshadern, Neurosurgical Department, Munich, Germany, 2Klinikum Grosshadern, Neuropathological Intitute, Munich, Germany, 3Klinikum Grosshadern, Nuclear Medicine Department, Munich, Germany Objective: Information about the MGMT (O6-methyl-guanine DNA methyltransferase) promoter methylation status and LOH (loss of heterozygosity) on 1p and/or 19q becomes increasingly important for prognostic evaluation and treatment decision in glioma patients. The aim of this prospective study (10/2006–10/2007) was to evaluate whether (1) small samples obtained from stereotactic biopsy are sufficient for the determination of the MGMT and LOH status, and (2) extended biopsy procedures (which are necessary for additional molecular-genetic characterization) are associated with an increased risk. Materials and Methods: Molecular stereotactic biopsy was indicated in case of highly eloquent tumor location and/or significant co-morbidity. Multiplanar trajectory planning with the BrainLab navigation software was based on co-registrated CT, MRI, and 18F-FET PET data. A serial biopsy was taken along a trajectory representative of the solid tumor including the area with the highest FET uptake. The maximum amount of tissue per specimen was 1 mm3. At least two samples collected from different sites were used for molecular-genetic analysis. Methylation-specific PCR for determination of promoter methylation and microsatellite analysis for LOH1p19q were specifically adopted for small sample sizes. Any adverse sequel potentially attributable to the biopsy procedure was considered as morbidity. Results: 216 patients were included. Histo-pathological evaluation revealed 41 astrocytomas WHO grade II, 47 astrocytomas WHO grade III, 23 oligodendrogliomas/oligoastrocytomas (grade II/III), and 105 glioblastomas. The MGMT and LOH 1p/19q status could be determined in 99.5%. The overall promoter methylation rate was 50% and LOH on 1p/19q was seen in 28%. An isolated allelic loss on 1p or 19q was found in 3% and 8% of patients, respectively. 12–24 tissue samples per tumor were considered necessary by the neurosurgeon and the intra-operatively attending neuropathologist to achieve a sufficient tumor characterization. Tissue samples taken from distinct sites throughout the tumor always revealed the same MGMT and LOH 1p/19q pattern. The transient morbidity rate was 0.48%. There was no permanent morbidity and no mortality. Conclusion: Because of its homogeneous distribution within each tumor, information about the MGMT promoter methylation and the LOH pattern on 1p and 19q can be reliably obtained from small sized stereotactic biopsies. Extensive but still minimally invasive biopsy procedures can be done with minimal risk using a guided multimodal imgaging approach. O56. INTEGRATION OF METABOLIC IMAGING AND MOLECULAR GENETIC PROFILING OF SERIAL STEREOTACTIC BIOPSIES ARE VALUABLE FOR HISTOLOGICAL DISCRIMINATION OF OLIGODENDROGLIOMAS, MIXED OLIGOASTROCYTOMAS AND ASTROCYTOMAS WHO° II/III N. Thon1, C. Erös1, G. Pöpperl2, J. Herms3, J. Tonn1, F. Kreth1; 1Department of Neurosurgery, Munich, Germany, 2Department of Nuclear Medicine, Munich, Germany, 3Institute of Neuropathology, Munich, Germany Introduction: Modern treatment strategies of gliomas have to consider recent advances in metabolic imaging and molecular markers with respect to individualized multimodal therapeutic regimes. Aim of this study was to correlate 18F-FET-PET based tumor grading, LOH1p/19q, and MGMT promoter methylation with histological classification of gliomas WHO° II and III from serial stereotatic biopsies in patients with eloquently located tumors. Methods: 86 patients have been included in this prospective, single-center study. Dynamic 18F-FET PET studies have been matched with MRI scans prior to stereotactic surgery to mark regions of interest. Oligodendroglial tumor characterization by 18F-FET PET was performed using max standard uptake value (mSUV) combined with kinetic uptake analysis. Biopsies have been classified according to WHO criteria. LOH1p/19q and MGMT methylation status has been detected using small tissue samples adjusted fluorescence in situ hybridization and methylation-specific PCR methods. Results: 8 oligodendrogliomas (O), 24 mixed oligoastrocytomas (OA), and 54 astrocytomas (A) (WHO° II and III) have been included. 1p/19q codeletion (33/78 = 42.3%) was significantly more frequent in tumors containing an oligodendroglial component (25/31 O+OA [80.7%] versus 8/47 A [17.0%]; p<0.05). 55/75 gliomas (73.3%) exhibited methylation at the MGMT gene (26/28 O+OA [92.9%] versus 29/46 A [63%]; p<0.05). Oligodendroglial tumors showed significantly elevated LOH 1p/19q and MGMT methylation coexpression status compared to astroglial tumors (24/28 O+OA [85.7%] versus 6/45 A [13.3%]; p<0.05). Oligodendroglial tumors (24/26) have been reliably identified by analyzing 18F-FET-PET mSUV and uptake kinetics (22/26 O+OA [84.6%]). 43 out of 79 patients underwent multimodal treatments prior to stereotactic procedure. In case of LOH 1p/19q and MGMT methylation coexpression status 11/11 newly diagnosed patients with oligodendroglial tumors were initially treated with chemotherapy. 2/2 oligoastrocytomas without LOH/MGMT methylation underwent primary radiotherapy. Conclusion: Combination of metabolic 18F-FET-PET analysis and molecular genetic marker profiling with histopathological classification of serial stereotactic biopsies was sufficient to gather more information on the difficult discrimination of oligodendroglial tumors and mixed oligoastrocytoma from astrogliomas. Since MGMT and LOH are correlated with favourable prognosis in certain glioma entities this diagnostic strategy can evaluate the role of molecular markers in a more general concept of glioma therapy. O57. PRIMARY GLIOBLASTOMA TREATED WITH BORON NEUTRON CAPTURE THERAPY—EVALUATION OF A PROLONGED HIGH DOSE OF BORONOPHENYLALANINE (BPA) R. Henriksson1, J. Capala2,3, A. Michanek4, S. Lindahl5, L. G. Salford6, L. Franzén1, E. Blomquist7, J. Westlin8, T. A. Bergenheim9; 1Dept of Radiation Science, Umeå University, Umeå, Sweden, 2Studsvik Medical Co, Nyköping, Sweden, 3Unit for Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden, 4Dept of Oncology, Sahlgrenska University Hospital, Gothenburg, Sweden, 5Dept of Oncology, Karlstad Central Hospital, Karlstad, Sweden, 6Dept of Neurosurgery and Radiation Physics, Lund University Hospital, Lund, Sweden, 7Dept of Radiation Oncology, Uppsala University Hospital, Uppsala, Sweden, 8Dept of Oncology, Central Hospital, Eskilstuna, Sweden, 9Dept of Neurosurgery, Umeå University, Umeå, Sweden Background: The aim of the present study was to evaluate the effects of BNCT in the treatment of glioblastoma multiforme using a novel protocol for the boronophenylalanine-fructose (BPA-F) infusion. Methods: The study included thirty patients, 26 to 69 years old with a good performance status, of which 27 have undergone debulking surgery. BPA-F (900 mg BPA/kg body weight) was given i.v. over 6 hours. Neutron irradiation started 2 hours after the completion of the infusion. We also used microdialysis to investigate the extracellular in vivo kinetics of boron in three intracerebral compartments—solid tumor, brain adjacent to tumor (BAT), and the normal brain, as well as the subcutaneous tissue before, during, and after BNCT treatment. Results: In tumor tissue the extracellular concentration of BPA followed that of blood with a maximal concentration of 31.2 ppm and a maximal ratio vs. blood of 1.07. In BAT, the peak level delayed for 4–6 h compared to the peak in blood with a maximal ratio of 1.2. The uptake of BPA in the normal brain was lower compared to the blood and tumor tissue. The boron-blood concentration during irradiation was 15.2–33.7 μg/g. The average weighted absorbed dose to normal brain was 3.2–6.1 Gy (W). The minimum dose to the tumor volume ranged from 15.4 to 54.3 Gy (W). Seven patients suffered from seizures, 8 from skin/mucous problems; 5 patients were stricken by thromboembolism and 4 from abdominal disturbances in close relation to BNCT. Four patients displayed 9 episodes of grade 3–4 events (WHO). At the time for follow-up, minimum 10 months, 23 out of the 29 evaluable patients were dead. The median time from BNCT treatment to tumor progression was 5.8 months and the median survival time after BNCT was 14.2 months. Conclusion: The efficacy of BNCT in the present protocol seems to be comparable with conventional radiotherapy. However, the observed side effects and the requirement of complex infrastructure emphasize the need of further evaluation, especially directed to improve the accumulation of 10B in tumor cells. O58. SURVIVAL BENEFIT FROM BORON NEUTRON CAPTURE THERAPY FOR NEWLY DIAGNOSED GLIOBLASTOMA PATIENTS N. Nonoguchi1, S. Kawabata1, S. Miyatake1, K. Iida1, S. Miyata1, K. Yokoyama1, T. Kuroiwa1, M. Kirihata2, Y. Imahori3, K. Ono4; 1Osaka Medical College Hospital, Takatsuki, Japan, 2Osaka Prefectural University, Osaka, Japan, 3CICS Corporation, Tokyo, Japan, 4Kyoto University Research Reactor Institute, Sakai, Japan Objective: Since 2002, we have applied BNCT for over 50 cases of malignant gliomas with epithermal neutron and two different boron compounds (BSH and BPA). BNCT is a binary cancer therapy involving the administration of B10-containing compounds which concentrate to tumor and subsequent irradiation with a neutron beam. The neutrons interact with the boron to cause the boron atom to split into an alpha particle and lithium nucleus. Both of these particles have short ranges equivalent to one cellular diameter, and therefore, BNCT can be thought of as a tumor-selective particle radiation. Here we examined the survival benefit of BNCT for 22 cases of newly diagnosed glioblastoma (NDGB) patients. Methods: We have treated 22 cases of NDGB with surgical removal followed by BNCT. The early 11 cases were treated with BNCT alone, and in the recent 11 cases, total 20 to 30 Gy fractionated external beam X-ray radiation therapy (EBRT) was additionally applied after BNCT mainly to the deep part of the tumor, where insufficient neutron fluence was simulated. No chemotherapy was applied until tumor progression was observed. Survival benefit of BNCT was analyzed with reference to the RTOG Recursive Partitioning Analysis (RPA) database and our institutional historical controls. Results: Treatments were well tolerated without any kinds of acute systemic or local severe toxicity in all patients. Mean overall survival of all NDGB patients treated by BNCT (N=22) was 22.8 months and the median survival time (MST) was 16.7 months with 2-year survival rate of 39.4%. Especially, patients treated with BNCT followed by EBRT (N=11) achieved longer MST, 21.3 months with 2-year survival rate of 57.1%, without the significant increasing in frequency of radiation necrosis after treatment. Stratification by RPA criteria showed 8, 10, and 4 patients in class III to V, respectively. Four patients of 8 in class III and 2 of 12 in class IV are still alive, and all the patients in class V have died at the time of analysis. MST for the BNCT group compared to the RTOG database was as follows: 19.8 months vs. 17.9 months for class III; 15.1 months vs. 11.1 months for class IV; 15.9 months vs. 8.9 months for class V. Conclusion: Our modified BNCT protocol showed a survival benefit in all of the RPA classes of the RTOG database not only for the good prognosis group, and the additional EBRT after BNCT might enhance the therapeutic benefit of BNCT and contribute to improve the prognosis of NDGB patients. O59. IMMUNOTHERAPY OF GLIOBLASTOMA WITH AUTOLOGOUS DENDRITIC CELLS M. Sabel1, M. Rapp1, Z. Özcan2, J. Fischer2, J. Rox2, R. Sorg2; 1Department of Neurosurgery, Duesseldorf, Germany, 2Institute for Transplantation Diagnostics and Cell Therapeutics, Duesseldorf, Germany Objective: Dendritic cell (DC)–based immunotherapy is a promising approach in glioblastoma. Patients are vaccinated with tumor-antigen loaded DCs. After vaccination, the DCs have to migrate to lymph nodes and there to induce specific anti-tumoral T-cell responses. We have established such a protocol and report here on initial results. Methods: Autologous tumor material is obtained from surgery. After minimal mechanical dissection, necrosis is induced and lysates are prepared. Monocytes enriched from leukapheresis products serve as the starting population for DC cultures. Successive generation of immature and mature DC for tumor lysate-loading and vaccination, respectively, are generated in a two-step culture system. Five vaccines are prepared and applied weekly by intradermal injection. Results: 22/22 tumor samples processed yielded a preparation of sterile, avital tumor cell lysates. For 12/22 of these preparations, GBM and a tumor content of at least 75% was confirmed neuropathologically. For 5 patients, vaccines were produced. From leukapheresis products containing 1.5±0.1×1010 leukocytes with a monocyte frequency of 25.5±1.1%, monocytes were enriched to 97.6±0.9% purity. Immature and mature DC obtained after 6 and 9 days of culture showed typical phenotypic and functional properties of bona fide DC, including induction of anti-tumoral responses in vitro. Overall, for each patient 5 vaccines containing 3.1±1.0×107 cells each were produced with a final purity of CD83+ mature DC of 87.9±2.9%. Vaccination was well tolerated and severe adverse events have not been observed. In one patient there was clear evidence of anti-tumoral immunity induced by the vaccines. Two of the patients progressed and died early. One patient vaccinated after third recurrence died 260d after the last resection. One patient vaccinated between radiochemotherapy and temozolomide chemotherapy was progression free for 529d but died 663d after resection. Conclusion: Vaccine production in glioblastoma patients is feasible and early results of vaccination, including induction of anti-tumoral immunity, are promising. O60. IMAGING AND DOSIMETRY OF CONVECTION ENHANCED DELIVERY OF COTARA (131I-CHTNT-1/B MAB) IN PATIENTS WITH RECURRENT GLIOBLASTOMA K. D. Judy1, R. Lustig1, J. Lopinto1, S. Shen2, J. Fiveash2, J. Shan3; 1University of Pennsylvania, Philadelphia, PA, 2University of Alabama, Birmingham, Birmingham, AL, 3Peregrine Pharmaceuticals, Inc., Tustin, CA, USA Background: Cotara (131I-chTNT-1/B Mab) is a radioiodinated chimeric monoclonal antibody specific for histone H1 and DNA. Histones are found in the cell nucleus and upon cell death they are found tightly bound to DNA and thus can be exploited for TNT-1 targeting of degenerating or necrotic cells to selectively deliver 131I to the glioma cells. A clinical trial of patients with recurrent Glioblastoma is being undertaken to evaluate the maximum tolerated dose given as a single 25 hour intratumoral infusion. Methods: Eligible patients with recurrent glioblastoma tumor volume between 5–60 cc were treated first with a convection-enhanced intratumoral infusion dose of 3 mCi for imaging of Cotara to assess biodistribution and calculate radiation dose. They were then treated 2–4 weeks later with a second therapeutic intratumoral infusion dose of 1.5 mCi/cc gross tumor volume. Results: Three patients have been treated with tumors of 13.5 to 59.9 ml gross total volume. The second infusion delivered a therapeutic dose of Cotara ranging from 17.11 to 73.67 mCi per tumor/patient. All patients tolerated the infusions well. No dose limiting toxicities (DLT) were seen in any of the patients. There was no significant normal tissue uptake observed beyond background. The tumor had a concentration >100 times the normal brain in the contralateral hemisphere. The mean tumor-to-body dose ratio was 551 (range 223–732). The maximal non-CNS uptake was seen in the stomach ranging from 1.1% to 3.3% of the delivered dose (radiation dose 1.8–3.3 cGy/mCi). Post-treatment MRI showed marked peri-infusional edema at the 3 month post-treatment MRI. This edema responded to dexamethasone therapy. Conclusion: Cotara has been delivered safely via an intratumoral infusion directly into the brain with no DLT identified. We are presently enrolling patients at the 2.0 mCi/cc dose and expect to progress to the final dose of 2.5 mCi/cc. O61. RECURSIVE PARTITIONING ANALYSIS OF PROGNOSTIC FACTORS IN WHO GRADE III GLIOMA PATIENTS TREATED WITH RADIOTHERAPY OR RADIOTHERAPY PLUS CHEMOTHERAPY C. Park1, S. Lee2, C. Kim1, D. Kim2, S. Paek1, D. Kim1, D. Heo2, I. Kim3, H. Jung1; 1Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Republic of Korea, 2Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea, 3Department of Radiation Oncology, Seoul National University College of Medicine, Seoul, Republic of Korea Objective: We evaluated the survival probabilities in newly diagnosed WHO grade III glioma patient risk groups classified by the prognostic factors using recursive partitioning analysis (RPA). Methods: A total of 132 patients of anaplastic astrocytoma (AA, n=55), anaplastic oligodendroglioma (AO, n=67) and anaplastic oligoastrocytoma (AOA, n=10) were included in this study. All patients were treated with either radiotherapy or radiotherapy followed by PCV chemotherapy. Five possible prognostic factors such as histological diagnosis, age, performance status, extent of resection, and treatment were incorporated into RPA. Risk groups were defined by RPA and survival analysis performed to validate their prognostic values. Results: Four risk groups were defined by RPA. The lowest risk group was patients who were treated with radiotherapy followed by PCV after gross total resection (GTR) or patients who were treated with radiotherapy followed by PCV after non-GTR but had performance status ECOG grade 0. The low risk group was AO/AOA patients with ECOG grade > 0 who were treated with radiotherapy followed by PCV after non-GTR or patients with ECOG grade < 2 who were treated with radiotherapy only after GTR. The high risk group was AA patients with ECOG grade > 0 who were treated with radiotherapy followed by PCV after non-GTR or AO/AOA patients with ECOG grade < 2 who were treated with radiotherapy only after non-GTR. The highest risk group was AA patients with ECOG grade < 2 who were treated with radiotherapy only after non-GTR or patients with ECOG grade ⩾ 2 who were treated with radiotherapy only. Survival analysis showed significant differences in mean survival between groups: 163.4 months (95% CI: 144.9–182.0), 109.5 months (86.7–132.4), 66.6 months (50.8–82.4), and 27.7 months (16.3–39.0) respectively from lowest risk to highest risk groups (p=0.00). Conclusion: The present study shows that the RPA grouping can successfully predict the survival probabilities in patients with WHO grade III glioma. O62. QUANTITATIVE, PCR-BASED MGMT-METHYLATION ANALYSIS IN GLIOBLASTOMA MULTIFORME L. Mariani1, L. Andereggen1, M. Arnold2, I. Vajtai2, E. Vassella2; 1Department of Neurosurgery, University Hospital Inselspital, Bern, Switzerland, 2Institute of Pathology, University of Bern, Bern, Switzerland Tumor-methylation of the MGMT-promoter (MGMT-meth) is associated with a better prognosis in patients with glioblastoma multiforme (GBM) receiving standard treatment. Whether the degree of DNA methylation in the tumor tissue correlates with survival is however unclear. We developed a methylation-specific, primer extension based, PCR method to quantitatively assess the MGMT-meth status in a consecutive series of patients with GBM diagnosed and treated until end of 2007. We analyzed the impact of age, surgery (versus biopsy), MGMT-meth and LOH 1p/19q status on overall survival. To date, the data are available for 57 out of 85 patients (analysis ongoing). After a mean F/U of 14.9 months, 61% of patients had died. Only three patients had evidence of LOH 1p/19q (5%); 58% of patients did not show any evidence of MGMT-meth, 12% showed a >90% methylation, and the remaining 30% of the cases showed intermediate proportions of MGMT-meth (range: 18%–89%). Age (<50 versus >50 years), surgery (versus biopsy), and MGMT-meth status (any MGMT-meth versus none) were associated with overall survival in the Kaplan-Meyer analysis. There was no linear correlation between the amount of MGMT-methylation and survival in these preliminary data. Patients with GBM with detectable levels of MGMT-meth as low as 18% have a survival advantage compared to patients without detectable MGMT-promoter methylation. O63. PROGNOSTIC AND PREDICTIVE SIGNIFICANCE OF MGMT PROMOTER METHYLATION AND PROTEIN EXPRESSION IN GLIOBLASTOMA PATIENTS S. Spiegl-Kreinecker1, C. Pirker1,2, M. Filipits2, D. Lötsch1,2, J. Buchroithner1, J. Pichler3, R. Silye4, M. Micksche2, J. Fischer1, W. Berger2; 1Department of Neurosurgery, Linz, Austria, 2Institute of Cancer Research, Department of Medicine I, Medical University, Vienna, Austria, 3Internal Medicine, Wagner Jauregg Hospital, Linz, Austria, 4Institute of Pathology and Neuropathology, Wagner Jauregg Hospital, Linz, Austria The DNA repair enzyme O6-methylguanine-DNA-methyltransferase (MGMT) is known to be a key factor in limiting therapy success with temozolomide (TMZ) in glioblastoma (GBM) patients. In this study we have analyzed MGMT promoter methylation and protein expression in GBM primary cell cultures with respect to their prognostic and predictive quality. One hundred and six patients who underwent surgery at our department were included in this study. Patients had GBM (n=101) and gliosarcoma (n=5) according to WHO criteria. Subsequent to surgery patients received combined radiochemotherapy with TMZ (n=68) or radiotherapy alone (n=17). Twenty-one patients did not receive further therapy due to low performance status (11/21) or rapid worsening of performance status (10/21). Tumor-derived primary cell cultures were analyzed with respect to MGMT promoter methylation (n=89) by methylation specific PCR following DNA modification and protein expression (n=71) by Western blot. Prognostic and predictive significance of these two MGMT parameters was assessed using Cox models. Methylated MGMT gene promoter sequences were detected in 67% (60/89) of the investigated GBM samples. Out of the 60 cases with methylated sequences, 14 (23%) lacked any unmethylated DNA while the remaining 46 samples contained a mixed profile with varying proportions of methylated and unmethylated sequences. In 33% (29/89) GBM patients the MGMT promoter was completely unmethylated. Despite a significant association between MGMT promoter methylation status and protein expression (chi-square test; p=0.002) protein expression levels according to promoter methylation were strongly overlapping. With respect to overall survival (OS), patients with lack of MGMT expression lived significantly longer while promoter methylation showed no significant association. Moreover, MGMT expression, but not promoter methylation, was found to be strongly associated with TMZ therapy response predicting significantly shorter OS in TMZ-treated (p=0.003) versus untreated patient group. Summarizing the data we demonstrate, that epigenetic silencing via promoter methylation is an important but not exclusive mechanism regulating MGMT expression. Lack of MGMT protein expression but not promoter methylation is of superior quality as predictive factor for TMZ response of GBM patients. We conclude that MGMT expression, additionally to promoter methylation, should be considered as biomarker for GBM patients best-placed to benefit from TMZ-therapy. O64. ANTI-MGMT IMMUNOHISTOCHEMISTRY IN EORTC/NCIC TRIAL 26981/22981: OBSERVER VARIABILITY, LACK OF ASSOCIATION WITH MGMT PROMOTER METHYLATION STATUS AND PATIENT SURVIVAL IMPEDE ITS USE AS CLINICAL BIOMARKER IN GLIOBLASTOMA MULTIFORME: A TRANSLATIONAL RESEARCH PROJECT OF THE EUROPEAN ORGANIZATION FOR RESEARCH AND TREATMENT OF CANCER BRAIN TUMOR GROUP M. Preusser1, R. C. Janzer2, J. Felsberg3, G. Reifenberger3, R. Stupp4, T. Gorlia5, C. Marosi1, H. Heinzl6, J. A. Hainfellner7, M. Hegi8,9; 1Department of Internal Medicine 1, Medical University of Vienna, Vienna, Austria, 2Department of Neurology and Division of Neuropathology, Center Hospitalier Universitaire Vaudois, Lausanne, Switzerland, 3Department of Neuropathology, Heinrich-Heine-University, Düsseldorf, Germany, 4Multidisciplinary Oncology Center, Center Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland, 5Data Center, European Organization for Research and Treatment of Cancer, Brussels, Belgium, 6Core Unit for Medical Statistics and Informatics, Medical University of Vienna, Vienna, Austria, 7Institute of Neurology, Medical University of Vienna, Vienna, Austria, 8Laboratory of Tumor Biology and Genetics, Centre, University Romand de Neurochirurgie Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland, 9National Center of Competence in Research Molecular Oncology, Swiss Institute for Experimental Cancer Research, Epalinges, Switzerland Introduction: Epigenetic silencing of O6-methylguanine-DNA methyltransferase (MGMT) protein expression due to MGMT gene promoter methylation is considered to associate with a benefit of postoperative chemoradiotherapy in glioblastoma multiforme (GBM) patients. The aim of this study was to test the usability of MGMT immunohistochemistry (IHC) as clinical biomarker. Methods: We performed anti-MGMT immunostaining of a tissue microarray containing tissue samples of 164 GBM patients from the prospective, randomized EORTC/NCIC trial 26981/22981. Two commercial anti-MGMT antibodies (clones MT3.1 and MT23.2) were used. Immunostaining results were semiquantitatively evaluated by 4 observers from 3 laboratories using a predefined algorithm. We analyzed (a) inter- and intraobserver agreement on MGMT protein expression (kappa statistics), (b) correlation of MGMT protein expression with MGMT gene promoter methylation status (kappa statistics), and (c) association of MGMT protein expression with patient survival (log rank test). Results: Interobserver agreement on MGMT immunohisochemistry varied from slight to almost perfect and interobserver agreement ranged from substantial to almost perfect. MGMT protein expression showed poor to moderate correlation with MGMT gene promoter methylation status. We found no significant correlation of MGMT protein expression with patient surrvival. Conclusions: In glioblastoma, observer variability, lack of association with MGMT promoter methylation status and patient survival limit the usefulness of anti-MGMT immunohistochemistry as clinical biomarker for routine diagnostic purposes. Brain Pathol. 2008 O65. ASSOCIATION BETWEEN IMMUNOHISTOCHEMICAL TISSUE INHIBITOR OF METALLOPROTEINASES-1 (TIMP-1) SCORE AND PATIENT SURVIVAL IN GLIOMAS C. Aaberg-Jessen1, K. Christensen1, H. D. Schrøder1, H. Offenberg2, N. Brünner2, B. W. Kristensen1; 1Department of Pathology, Odense University Hospital, Odense, Denmark, 2Department of Veterinary Pathobiology, Univ. of Copenhagen, Copenhagen, Denmark A high TIMP-1 level has earlier been shown to be related to shorter survival in colorectal cancer and breast cancer suggesting that TIMP-1 might be an important prognostic biomarker. It has been suggested that TIMP-1 is involved in tumor invasion, proliferation, and apoptosis in different types of cancers. Whether TIMP-1 is a prognostic marker in gliomas has not yet been investigated, although TIMP-1 is known to be expressed in gliomas. The aim of the present study was to investigate the immunohistochemical expression of TIMP-1 in gliomas and relate this expression to patient survival. We used a new TIMP-1 monoclonal antibody (VT-7) on formalin-fixed paraffin-embedded tumor tissue from 23 diffuse astrocytomas, 17 anaplastic astrocytomas, and 72 glioblastomas. The staining of tumor cells and vessels were scored and compared with patient overall survival. Moreover, TIMP-1 in situ hybridization was performed on selected glioblastomas. The results showed that TIMP-1 protein was expressed in the vast majority of tumors being expressed in both tumor cells and vessels and in both central and invasive areas of the tumors. In situ hybridization for TIMP-1 mRNA on glioblastomas confirmed the expression of TIMP-1 protein. The fraction of stained tumor cells and vessels as well as the staining intensity varied between tumors of the same grade, but the mean staining score increased with tumor grade. The overall survival of glioblastoma patients was divided into four groups based on TIMP-1 score (0–5, 6–7, 8–9 or 10–12). The multivariate Cox regression test showed that patients with the lowest TIMP-1 expression (score 0–5; n=12) had a significantly longer overall survival (p=0.004). There was no significant correlation between TIMP-1 expression and overall survival for diffuse and anaplastic astrocytomas. In conclusion, the study shows that TIMP-1 immunohistochemical score is significantly associated with overall survival in glioblastoma patients, suggesting that TIMP-1 could be used as a new biomarker for this type of cancer. The shorter survival of patients with high TIMP-1 protein expression may be explained by the anti-apoptotic effect of TIMP-1 preventing apoptosis induced by radiation and chemotherapy. Accordingly, TIMP-1 or TIMP-1 interacting proteins could represent new targets in future anti-cancer therapy. O66. PROGNOSTIC SIGNIFICANCE OF NDRG2 PROMOTER HYPERMETHYLATION IN ATYPICAL AND ANAPLASTIC MENINGIOMAS A. Tortosa1, J. Bruna2, P. Roerig3, F. Martínez1, M. Riemenschneider3, S. Boluda4, P. Giménez-Bonafé5, G. Reifenberger3; 1Department of Basic Nursing, University of Barcelona, Barcelona, Spain, 2Servicio de Neurologia, Hospital de Bellvitge, Barcelona, Spain, 3Department of Neuropathology, Heinrich-Heine-University, Düsseldorf, Germany, 4Institut de Neuropatologia, Hospital de Bellvitge, Barcelona, Spain, 5Departament de Ciencies Fisiologiques II, University of Barcelona, Barcelona, Spain Background: As many as 20% of meningiomas display clinically aggressive features, leading to increased patient morbidity or mortality. NDRG2 promoter hypermethylation has been associated with aggressive behavior in patients with meningioma. Objective: The aim of the present study was to evaluate the prognostic significance of NDRG2 promoter hypermethylation in patients with atypical and anaplastic meningioma. Methods: Thirty-two patients with the diagnosis of WHO grade II and III meningioma (20 atypical and 12 anaplastic meningiomas) were included. Tumor DNA was extracted from microdissected formalin-fixed, paraffin-embedded sections (n=21) or frozen tissue when available (n=11). NDRG2 promoter methylation analysis was performed using sequencing of sodium bisulfite-modified DNA covering the 15 CpG sites frequently methylated in advanced meningiomas. Each CpG site was scored as strongly (3), moderately (2), weakly (1), and not methylated (blank) on the basis of the bisulfite sequencing results. For each tumor, a methylation score was calculated by adding the figures determined at the individual CpG sites. A second score was calculated by adding the figures obtained for the six CpG sites (F5/R7 region) immediately 5' to the promoter core region of the NDRG2 gene. Results: In the univariate analysis, factors influencing relapse-free survival were methylation of the F5/R7 region of the NDRG2 promoter and KPS. The multivariate analysis revealed that KPS ⩾70 (HR: 0.27; 95% CI: 0.083–0.913; p=0.035) was the only variable independently associated with longer relapse-free survival. NDRG2 promoter methylation (p=0.038), methylation of the F5/R7 region of the NDRG2 promoter (p=0.023) and KPS (p=0.033) were identified as variables with prognostic influence on overall survival in the univariate analysis. Cox's regression analysis showed that F5/R7 region of the NDRG2 promoter hypermethylation was the only variable independently associated with overall survival (HR: 0.238; 95% CI: 0.286–0.94; p=0.040). Conclusion: Hypermethylation of NDRG2 promoter, especially within the F5/R7 region, was independently associated with shorter overall survival in patients with atypical and anaplastic meningioma. O67. HEALTH-RELATED QUALITY OF LIFE OF LONG-TERM SURVIVING HIGH-GRADE GLIOMA PATIENTS I. Bosma, J. C. Reijneveld, L. Douw, M. J. Vos, T. J. Postma, W. P. Vandertop, B. J. Slotman, M. J. B. Taphoorn, J. J. Heimans, M. Klein; VU University Medical Center, Amsterdam, The Netherlands Goals: (1) to compare the health-related quality of life (HRQoL) of long-term to short-term high-grade glioma (HGG) survivors, (2) to determine the prognostic value of HRQoL for overall survival, and (3) to determine the effect of tumor recurrence on HRQoL of long-term survivors. Methods: Following baseline assessment (after surgery, before radiotherapy), self-perceived HRQoL (MOS SF-36) and brain tumor-specific symptoms (BCM-20) were assessed every 4 months up till 16 months after histological diagnosis. Kaplan-Meier survival analysis and the Cox proportional hazards model were performed to estimate overall survival of patients with impaired scores on the aggregated SF-36 higher-order summary scores measuring physical functioning (PCS) and mental functioning (MCS). Results: Sixteen patients with a short-term survival (baseline and 4-month follow-up) and 16 with a long-term survival (follow-up up till 16 months after diagnosis) were selected out of 68 initially recruited HGG patients. At baseline, the short-term and long-term survivors did not differ in their HRQoL. Between baseline and 4-month follow-up, HRQoL of short-term survivors deteriorated, whereas the long-term survivors improved to a level comparable to healthy controls. Patients with impaired mental functioning (MCS) at baseline had a shorter median survival than patients with a normal functioning. Accounting for differences in patient and tumor characteristics, it was not independently related to poorer overall survival. Not surprisingly, in the group of long-term survivors, the 5 patients with recurrence had a more compromised HRQoL at 16-month follow-up compared to the 11 patients without recurrence. Discussion: (1) Baseline HRQoL is not related to duration of survival. (2) Long-term survivors show improvement of HRQoL to a level comparable to that of the healthy. O68. COGNITIVE REHABILITATION OF GLIOMA PATIENTS: THE RESULTS OF A PROSPECTIVE, RANDOMIZED STUDY K. Gehring1, N. K. Aaronson2,3, M. M. Sitskoorn1,4, M. Klein5, T. J. Postma5, M. J. van den Bent6, G. N. Beute7, R. H. Enting8, A. C. Kappelle9, W. Boogerd10, T. Veninga11, A. Twijnstra12, D. H. Boerman13, M. J. B. Taphoorn14,15; 1Rudolf Magnus Institute of Neuroscience / UMC Utrecht, Utrecht, Netherlands, 2the Netherlands Cancer Institute, Amsterdam, Netherlands, 3University of Amsterdam, Amsterdam, Netherlands, 4Tilburg University, Tilburg, Netherlands, 5VU University Medical Center, Amsterdam, Netherlands, 6Erasmus MC, Rotterdam, Netherlands, 7St. Elisabeth Hospital, Tilburg, Netherlands, 8University Medical Center Groningen, Groningen, Netherlands, 9Radboud University Nijmegen, Nijmegen, Netherlands, 10Antoni van Leeuwenhoek Hospital, Amsterdam, Netherlands, 11Dr. Bernard Verbeeten Institute, Tilburg, Netherlands, 12University Hospital Maastricht, Maastricht, Netherlands, 13Rijnstate Hospital, Arnhem, Netherlands, 14Medical Centre Haaglanden, The Hague, Netherlands, 15VU University Medical Centre, Amsterdam, Netherlands Patients with (low-grade) gliomas not only suffer from epileptic seizures and neurological deficits, but also from cognitive deficits, including memory loss and problems with concentration. These cognitive deficits can have a negative impact on daily functioning and quality of life. This randomized controlled study evaluated the effects of a multifaceted cognitive rehabilitation program on cognitive functioning and aspects of quality of life in glioma patients. 140 adult patients with gliomas and favorable prognostic factors, whose disease was in remission, were recruited from 10 hospitals in the Netherlands. Patients with both subjective cognitive symptoms and objective cognitive deficits were randomized to either an intervention group or to a waiting-list control group. The intervention incorporated both computer-based attention retraining and individual teaching of compensatory strategies directed toward attention, memory, and executive functioning. The program consisted of six weekly individual two-hour sessions plus several hours of homework per week. Both study groups completed neuropsychological (NP) tests and questionnaires on cognitive functioning, fatigue, and quality of life at baseline, immediately following completion of cognitive rehabilitation (or at an equivalent time point for the control group), and at six months follow-up. Preliminary results (repeated measures [M]ANCOVA's) indicate significant effects at the post-treatment assessment on measures of self-reported cognitive functioning, burden of cognitive dysfunction, and mental fatigue favoring the intervention group. In objective NP test scores, no significant group differences at post-treatment were observed. At 6-month follow-up, however, significant intervention effects were found on NP tests of attention and verbal learning. Changes in executive functioning did not reach statistical significance. The effect on self-reported outcomes was less pronounced at this 6-month assessment. Cognitive rehabilitation of glioma patients has immediate positive effects on self-reported cognitive outcomes and positive effects on objectively assessed NP functioning over a longer period of time. O69. SURVEY ON THE HORMONAL SYSTEM AND FERTILITY IN WOMEN OF REPRODUCTIVE AGE AFTER RECEIVING THERAPY FOR MALIGNANT GLIOMA WHO III OR IV K. Elandt1, C. Kurz2, M. Hassler1, U. Dieckmann3, A. Rottenfusser3, C. Marosi1; 1MUW, Dept. of Oncology, Vienna, Austria, 2MUW, Dept. of Gynaecology, Vienna, Austria, 3MUW; Dept. of Radiotherapy, Vienna, Austria Background: Treatment of gliomas WHO III and IV is based on either radiation (RT) or chemotherapy (CT) and may cause an endocrine deficiency in women of reproductive age. We tried to evaluate hormonal changes and their impact on quality of life in women with malignant gliomas. Methods: We examined the hormonal status of 22 female patients with high-grade gliomas (aged 28 to 48 years) after whole brain RT and during CT. The cumulative dose of radiation ranged from 50 to 66 Gy and all received first line CT, most frequently temozolomide or the combination of fotemustine with dacarbazine, nine of them had second line therapy and two were under third line treatment. Serum concentrations of gonadal, pituitary, and thyroid hormones were measured at the start and the end of chemotherapy. Vaginal ultrasound was performed within the fist cycle of CT and patient quality of life was assessed by questionnaires EORTC QLQ-30. Results: 19 patients (86%) showed change in menstrual pattern. Ten had an amenorrhoea with a mean duration of 26.1 months (ranged from 4 to 96 months), and 6 presented with oligomenorrhea or hypomenorrhea. Four females showed low hemoglobin levels, without relation to CT, and all of them reported hypermenorrhea at variable intervals. Serum concentration of prolactin was elevated in 12 patients, and 11 of them presented with amenorrhoea. Sixteen of the pre-menopausal women (72%) had low level of estradiol and 8 (36%) had low progesterone serum concentrations. Overall, 10 patients had evidence of hypogonadism and a postmenopausal hormone pattern. Two presented with a latent hypothyroidism, and four had lower serum concentrations of TSH, total thyroxine, or total triiodothyronine than in normal subjects. The QLQ evaluation showed that patients frequently reported about fatigue and described feelings of postmenopausal women, like flushes, weakness, and gain of weight. Among 22 patients, 12 had uneventful pregnancies (ranged 1 to 3) before diagnosis of a malignant glioma, and none of them expressed a wish to preserve their childbearing potential or to become pregnant. The decrease of libido combined with loss of the feeling to be attractive as a female, with a need for tender care and security on the other hand, led to problems in their partnerships. Conclusions: The hormonal deficits caused by RT and chemotherapy need a careful evaluation as well as individualized measures of diagnostics and treatment. O70. ATTITUDES TO DIAGNOSING AND TREATING DEPRESSION IN GLIOMA: A QUESTIONNAIRE SURVEY OF FIVE SPECIALTIES A. G. Rooney1, A. Carson2, I. R. Whittle1, S. Erridge1, R. Grant1; 1Edinburgh Centre for Neuro-oncology, Edinburgh, United Kingdom, 2Royal Edinburgh Hospital, Edinburgh, United Kingdom Background: Depression is often under-diagnosed and under-treated in cancer. Depressed glioma patients may present both a diagnostic challenge (due to uncertainty over the significance of understandable symptoms) and a treatment challenge (due to a risk of antidepressant-induced seizures). Little is known of the current attitudes of clinicians in this area. Aim: To explore attitudes among five specialty groups towards (1) diagnosing and (2) treating depression, in a patient with glioma and a history of seizures. Method: We created a clinical case study of a patient with a glioma and previous seizures, which met 7/9 criteria for DSM-IV Major Depressive Disorder. We sent it, with a questionnaire, to consultants in neurology, clinical oncology, neurosurgery, and liaison psychiatry in Scotland (UK) and to the GPs of all glioma patients on our local database (total n=228). Results: Responses were received from 105 doctors (46% response rate). Sixty-five diagnosed depression (62%); the remainder considered the presentation an “understandable reaction.” Forty of those identifying depression chose an antidepressant as first-line treatment (62%). No statistically significant differences were found between specialties in respect of diagnosing depression (p=0.16) or readiness to prescribe an antidepressant (p=0.11). GPs and psychiatrists were more likely to consider themselves best-placed to lead the management of depression (both p=<0.00001). Among respondents identifying depression, concern about seizures was higher in both GPs (p=0.006) and psychiatrists (p=0.03) than neurologists. Across the whole sample, higher seizure anxiety was significantly associated with lower antidepressant prescribing rates (p=0.04). Discussion: Almost four in ten respondents did not identify major depression in a case study of a depressed patient with a glioma. There was also poor agreement on how to treat it, with almost four in ten of those diagnosing depression opting for first-line management other than an antidepressant. In the whole sample, only 38% of respondents would have diagnosed and appropriately treated the depression. Since GPs and psychiatrists felt significantly more confident about leading management of depression than neuroscientific specialties, and significantly less confident about managing seizures than neuroscientists, multidisciplinary management may be beneficial for these patients. However as some analyses were exploratory, results should be interpreted with caution. O71. ENDOCRINE FUNCTION AFTER CRANIOSPINAL IRRADIATION FOR MEDULLOBLASTOMA IN CHILDREN AND ADULTS S. Beltran1, M. El Rawas1, M. Sunyach2, P. Berlier2, C. Conter2, F. Borson-Chazot3, D. Frappaz2; 1Fédération d'Endocrinologie groupement hospitalier Est, Bron, France, 2Centre Léon Bérard, Lyon, France, 3Fédération d'Endocrinologie groupement hospitalier Est, Lyon, France Background: Craniospinal radiation (CSI) is the cornerstone of the treatment of medulloblastoma, but may damage hypothalamic pituitary function. There are many publications reporting endocrinological toxicity of CSI in children, but little is published on adults. Objective: To study the prevalence of pituitary deficits, following CSI in children (<15 years at radiotherapy) and adults. Method: A series of 30 patients (16 children, 14 adults) treated by surgery, radiotherapy, and chemotherapy for a medulloblastoma was retrospectively studied. The children group was composed of 5 pubescent girls and 11 boys (3 pubescent)). Age at radiotherapy ranged between 5 and 12 years. Delay between CSI and evaluation was 1–9 years. Adult patients were 4 women (3 menopausal) and 10 men. Age at radiotherapy ranged between 15 and 40 years. Delay between CSI and evaluation was was 1–24 years. GH and adrenal axes were assessed using stimulation tests (insuline tolerance, glucagon-propanolol, and synacthene test). Gonadotropin and thyrotropin functions were tested using baseline blood measurements. Results: Hypopituitarism was present in 57.2% of adult patients and 87.5% of children. The most frequent deficit was GH deficiency, respectively observed in 35.7% and 62.5 % and significantly associated with the young age of radiotherapy (p< 0.05). ACTH deficiency was rare, observed in 7.1% of adults and 12.5% of children. Hypothyroidism from central or peripheral origin was recorded in 21.4% of adults and 31.2% of children. Finally, gonadotropin deficiency was observed in 35.7% of adults and 6.2% of children. Two children have developed a peripheral gonadal insufficiency. Conclusion: Both adult and children treated with CSI for a medulloblastoma are at high risk of hypopituitarism (especially GH deficiency) which depends on age at time of RT. Long term surveillance and periodic evaluation are needed in children and adults. O72. THE IMPACT OF COGNITIVE DEFICITS AND EPILEPSY ON QUALITY OF LIFE IN MENINGIOMA PATIENTS AFTER TREATMENT M. L. Waagemans1, M. Dijkstra1, D. van Nieuwenhuizen1, M. Wumkes2, C. M. F. Dirven1, J. C. Reijneveld1, M. Klein1, L. J. A. Stalpers2; 1VU University Medical Center, Amsterdam, The Netherlands, 2AMC-University of Amsterdam, Amsterdam, The Netherlands Background: Meningioma patients are the most prevalent brain tumor survivors. Despite their good prognosis, surprisingly little is known about the long-term health-related quality of life (HRQOL) sequelae. In this study we investigated HRQOL in WHO grade I meningioma patients following treatment and the impact of cognitive deficits, epileptic seizures, and antiepileptic drug (AED) use. Methods: Eighty-nine WHO grade I meningioma patients who underwent surgery with or without adjuvant radiotherapy were individually matched to 89 healthy controls for age, sex, and educational level. We assessed HRQOL by means of the SF-36 questionnaire. We measured cognitive functioning through a neuropsychological test battery and assessed epileptic seizure frequency and AED use of each patient. Student's t-tests were performed to test for differences in HRQOL between patients and healthy controls, between patients with or without AED use, and between patients with or without seizures. By using stepwise linear regression analysis, we additionally correlated HRQOL with cognition, corrected for age, sex, and educational level. Results: Except for role limitations caused by physical problems (p=0.015) meningioma patients did not differ from healthy controls in any of the 8 HRQOL scales. However, the 23 patients using AEDs had significantly lower HRQOL scores in 5 out of the 8 SF-36 scales when compared with healthy controls. Analysis of the patients using AEDs showed no significant differences in HRQOL between patients with or without epileptic seizures. Impaired cognition had also a negative impact on HRQOL; regression analysis demonstrated impaired executive functioning to be correlated with lower scores on 7 out of 8 HRQOL scales (p<0.05). Furthermore, deficits in other cognitive domains, except for working memory, also negatively affected quality of life, albeit to a lesser extent. Conclusions: Health-related quality of life is unaffected in most meningioma patients. Subgroups of patients with cognitive deficits and/or patients using AEDs, however, have a decreased HRQOL. Incomplete seizure control among patients using AEDs does not further deteriorate their HRQOL. POSTERS Poster numbers marked with * were also presented orally in a Poster Session. P001*. HYPERFRACTIONATED ACCELERATED RADIOTHERAPY (HART) WITH CHEMOTHERAPY FOR METASTATIC MEDULLOBLASTOMA (MB): PRELIMINARY REPORT OF THE CHILDREN'S CANCER AND LEUKAEMIA GROUP (CCLG) STUDY R. E. Taylor1, N. Boota2, S. Bujkiewicz2, J. Lucas2, K. J. Robinson2, K. Robson3, F. Saran4, A. Michalski5, B. Pizer6; 1South West Wales Cancer Centre, Swansea, United Kingdom, 2Children's Cancer and Leukaemia Group, Leicester, United Kingdom, 3Nottingham University, Nottingham, United Kingdom, 4Royal Marsden Hospital, London, United Kingdom, 5Great Ormond Street Hospital, London, United Kingdom, 6Alder Hey Hospital, Liverpool, United Kingdom MB is a rapidly proliferating tumor arising in the posterior fossa and seen mainly in children. Standard therapy includes craniospinal radiotherapy (CSRT) and adjuvant chemotherapy. Patients presenting with leptomeningeal metastases (Chang Stage M1–3) have a poor outcome and current research is aimed at improving treatment for these patients, including the investigation of novel therapies. A HART regimen could improve the therapeutic ratio for RT by the use of acceleration in addition to hyperfractionation and thus minimize tumor cell repopulation during RT. The purpose of this study was to evaluate the feasibility and toxicity of a regimen comprising HART (1.24 Gy twice daily) with concomitant and adjuvant chemotherapy for metastatic MB. Between February 2002 and October 2007, 25 eligible patients (16 male, 9 female) aged 3–13 (median 7, mean 7.8) with M1–3 medulloblastoma were entered into the study. Initial management was with maximum surgical resection of the primary, followed by HART. Treatment then continued with 8 cycles of adjuvant chemotherapy. The CSRT dose was 39.68 Gy in 32 fractions, followed by a boost to the whole posterior fossa of 22.32 Gy in 18 fractions. Where appropriate, boosts to metastases of 9.92 Gy in 8 fractions were given. Adjuvant chemotherapy consisted of Vincristine (VCR) 1.5 mg/m2, CCNU 75 mg/m2, and Cisplatin 70 mg/m2. The first 7 patients did not receive VCR concurrent with RT. The eighth and subsequent patients received VCR 1.5 mg/m2 weekly × 8 doses starting during the first week of RT. Of 25 patients entered into the study, 23 have completed HART. One patient had an interruption to HART because of an intercurrent infection. HART has been completed with a median duration of 34 days (range: 32–38). The numbers of patients experiencing grade 3–4 toxicity include anaemia: 3, thrombocytopenia: 2, leucopenia: 14, mucositis: 3, radiation dermatitis: 3, nausea: 5, and vomiting: 2. Of the 14 patients who have completed all treatment, 8 received all 8 cycles of chemotherapy, 4 have received 7 cycles, 1 has received 5 cycles and one received no chemotherapy. To date, 6/25 patients have relapsed and 5 have died following relapse. Data on event-free survival will be presented. In conclusion the HART regimen is tolerable and could be delivered in all patients without any major delay, and can be incorporated into multimodality management including chemotherapy. P002*. SEQUENTIAL HIGH-DOSE CHEMOTHERAPY AND REDUCED CRANIOSPINAL IRRADIATION IN YOUNG CHILDREN WITH METASTATIC MEDULLOBLASTOMA C. Dufour1, D. Couanet1, D. Figarella-Branger2, C. Carrie3, F. Doz4, C. Sainte-Rose5, M. Raquin1, A. Laplanche1, J. Grill1, C. Kalifa1; 1Gustave Roussy, Villejuif, France, 2CHU, Marseille, France, 3Léon Bérard, Lyon, France, 4Curie, Paris, France, 5Necker-Enfants Malades, Paris, France Introduction: Prognosis of disseminated medulloblastomas (DMB) is poor and treatment remains a major challenge in young children because of the late toxicity of standard dose craniospinal irradiation (CSI). We developed therefore a new strategy based on sequential high-dose chemotherapy (HDC) followed by autologous stem cell transplantation (ASCT) and reduced dose CSI. Patients and Methods: Thirty-four children were enrolled in this phase II study. Median age at diagnosis was 3.2 years (range, 0.8 to 7). Chang stages were M1 (6 pts) and M3 (28 pts). After initial surgery, children received two courses of carboplatin-etoposide; then peripheral blood stem cells were harvested. In absence of disease progression, five sequential courses of chemotherapy followed by ASCT were performed: melphalan (100 mg/m2) at day 43, cisplatin (100 mg/m2) at day 64, melphalan at day 85, cisplatin at day 106 and thiotepa (720 mg/m2) at day 127. Children with resectable tumor residue were operated at the end of chemotherapy. Treatment was completed by age-adapted CSI. Results: At the end of the chemotherapy 11 pts were in CR, 7 in PR. Out of the 19 pts who completed the treatment, 13 children are alive in CR1 (median follow-up, 26 months). Delivered doses of CSI were 50 Gy to the posterior fossa and 18 Gy to the brain and spinal canal in 3 pts, 50 Gy and 24 Gy in 6, and 50 Gy and 35 Gy in 1. The overall survival is 50% at 30 months. The haematological toxicity was high but manageable; no toxic death was observed. Conclusion: This chemotherapy regimen combined with reduced dose CSI produced a survival that compares favorably with published data. A longer follow-up is necessary to assess long-term quality of life. P003*. MEDULLOBLASTOMAS: CLINICO-PATHOLOGIC REVIEW OF 51 PATIENTS AND DISCLOSURE OF UNSUSPECTED AT/RT M. Suñol, O. Cruz, E. Rodriguez, V. Cusí, A. Guillen, M. Medina, N. Perez, J. Mora; Hospital St Joan de Deu, Esplugues de Llobregat, Barcelona, Spain Aim: To review clinical and histological characteristics of patients diagnosed with meduloblastoma and evaluate their prognostic strength. Material and Methods: Retrospective study, including 51 patients diagnosed with medulloblastoma from 1982 to 2004. Clinical and Histological variables were analyzed, including histological variants, mitotic activity, microvascular proliferation, pseudopalisading necrosis, and neuroblastic rosettes. Additionally, a tissue microarray including synaptophysin, neuronal specific enolase (NSE), glial fibrilar acidic protein (GFAP), neurofilaments-68 (NF68), epitelial membrane antigen (EMA), vimentin, Wilms tumor protein 1 (WT1), c-erbB2, p53 protein sobreexpression (p53), INI-1 and ki67 expression was performed. Results: The average age at diagnosis was 5.6 years old. The overall survival (OS) was 37.5%, although survival improved steadily in recent cohorts. According to the histological parameters, the desmoplastic and the extensive nodularity were variants with better OS, whereas tumors with more than 20 mitosis/10HPF were associated with a worse prognosis and low OS. IHC analysis showed synaptophysin expression in 76.6% of cases, NSE 100%, GFAP 31.9%, NF68 36.2%, EMA 8%, vimentin 34%, WT1 (cytoplasmic) 25.6%, cerbB-2 4.4%, p53 6.7%, and INI-1 93.5%. Ki67 expression was >50% in 23.5% of cases, 20–50% in 41.2% and <20% in 35.3% of cases. It is remarkable the lack of INI-1 expression in 3 tumors previously diagnosed as meduloblastoma, which suggested the diagnosis of Atypical Teratoid/Rhabdoid tumor (AT/RT). This was further confirmed by hSNF5/INI1 gene mutation. Conclusion: Desmoplastic and extensive nodularity subtypes correlate with better prognosis; likewise, less than 20 mitosis/10HPF. AT/RT show similar histology and IHC markers as medulloblastoma, but INI-1 negative expression identify AT/RT, being essential to perform IHC for INI-1 in pediatric embryonal CNS tumors to disclose a possible AT/RT. P005. MALIGNANT INTRACRANIAL GERM CELL TUMORS IN CHILDREN AND ADOLESCENTS: RESULTS OF MULTIMODAL TREATMENT M. A. Dragomir1, E. Gruber2, R. Anghel3, C. Rosca4, A. Ciurea5, I. Tascu6, C. Radu7; 1Pediatric Oncology, Institute of Oncology Prof. Dr. Al. Trestioreanu, Bucharest, Romania, 2Pediatric Oncology, Institute of Oncology Prof. Dr. Al. Trestioreanu, Bucharest, Romania, 3Radiotherapy, Institute of Oncology Prof. Dr. Al. Trestioreanu, Bucharest, Romania, 4Radiotherapy, Institute of Oncology Prof. Dr. Al. Trestioreanu, Bucharest, Romania, 5Pediatric Neurosurgery, Neurosurgical Clinics, Emergency Hospital Bagdasar-Arseni, Bucharest, Romania, 6Pediatric Neurosurgery, Neurosurgical Clinics, Emergency Hospital Bagdasar-Arseni, Bucharest, Romania, 7Pediatric Oncology, Institute of Oncology Prof. Dr. Al. Trestioreanu, Bucharest, Romania Purpose: To evaluate the clinical features and outcome (symptomatology of the onset and long term sequelae) in intracranial germ cell tumors (GCTs) and the results of the multimodal treatment. Methods and Patients: We retrospectively analyzed 24 cases treated in our institute between 1995–2005. Patients' characteristics: overt predominance of male cases (80%); age limits: 8 and 30 years old; the most frequent sites: sellar and pineal region (70%). The therapeutic approach was varied in the studied group. The multidisciplinary treatment consisted in: surgery (S)+ radiation therapy (RT)+ chemotherapy (ChT) in 40% of patients (pts); S+ RT in 31% of pts; RT+ ChT in 4 pts. Surgery was performed in 20 pts: subtotal and cvasitotal resections (66 %) and biopsies (33%). 70% of pts underwent RT on different fields (cranial, localized, or craniospinal) and in varied doses (2,000–5,600 cGy). Starting with 2002, the therapy approach was unitary and adapted to the international standard SIOP-CNS-GCT 96: limited S with diagnostic purpose + ChT (2–4 cycles) + RT (cranial field, 2,400–3,000 cGy in complete response or 3,000–3,600 cGy in partial response, + spinal irradiation in cases with malignant cells in cerebrospinal fluid). According to the same international standard, the definitive diagnosis was accepted without biopsy in pts with characteristic radiological aspects correlated with high-levels of tumor markers (CEA, AFP) in serum and/or cerebrospinal fluid. ChT comprised two types of protocols: BEP and ETO+ IFO+ DDP. Discussion: 70% of cases were registered in patients aged >10 years, 50% of pts were between 15–25 years old. The predominant symptoms: headaches: 75% of pts, visual disturbances (diplopya, strabismus, poor vision): 75% of pts, and diabetes insipidus: 40%. Increased intracranial pressure urged the installing of ventriculo-peritoneal shunts in 11 pts. The long-term sequelae were endocrine disturbances: diabetes insipidus (7 pts), global hypophysis impairment (1 pt), hypothyroidism (1 pt); ophthalmologic impairments (8 pts); equilibrium deficiencies (2 pts); and hearing disturbances (1 pt). Results: Overall survival evaluated by Kaplan-Meier method: 84%. Median survival: 137 months. We registered recurrences in 5 pts and cerebral and/or bone marrow metastases in 3 pts. DFS: 20 months. In 4 cases complete remission of tumors after 4 cycles of pre-irradiation chemotherapy was registred. In 6 cases partial remission of tumors (>75%) was registred after pre-irradiation ChT. Conclusions: (1) The current multidisciplinary therapeutic approach entails a minimize of the late side-effects by reducing the cranial irradiation efficient dose. (2) The surgical approach limited to a diagnostic purpose obviate important endocrine and ophthalmologic long-term sequelae. (3) Pre-irradiation ChT have in important impact for long term complete remission of tumors. P006. TOLERABILITY OF BEVACIZUMAB IN 16 CHILDREN WITH INTRACRANIAL TUMORS —A SINGLE CENTER EXPERIENCE B. Reismüller, A. A. Azizi, M. Gruber-Olipitz, A. Peyrl, A. Gupper, I. Slavc; Department of Pediatrics and Adolescent Medicine, Vienna, Austria Background: Bevacizumab (BV), a monoclonal antibody against vascular endothelial growth factor (VEGF), has proven anti-cancer activity in a number of solid tumors. Regarding intracranial tumors concern exists with respect to intratumoral hemorrhage associated with BV. We report the tolerability and feasibility of a compassionate use BV treatment in 16 patients with intracranial tumors. Patients and Methods: We retrospectively analyzed 16 children (11 male, 5 female) with intracranial tumors. The diagnoses were glioblastoma WHO°IV (n=1), diffuse intrinsic pons glioma (n=1), medulloblastoma (n=2), supratentorial primitive neuroectodermal tumor (n=2), anaplastic astrocytoma WHO°III (n=1), anaplastic ependymoma WHO°III (n=1), atypical teratoid rhabdoid tumor (n=1), CNS germ cell tumor (n=1), pilomyxoid astrocytoma (n=2), pilocytic astrocytoma (n=2), clear cell meningeoma (n=1), and metastatic alveolar soft part sarcoma (n=1). Except for one patient (no parental consent for chemotherapy) all patients received BV for recurrence/progression of their disease. The median age at start of BV treatment was 9.6 years (range 1.5–18 years). The dose ranged from 5–10 mg/kg (median 8.18 mg) and was administered intravenously every 2–4 weeks. A total number of 255 BV courses was administered (median per patient: n=16, range 2–46). Except for one patient all patients received additional chemotherapy or oral four-drug antiangiogenic metronomic therapy concomitant to BV. Results: BV was well tolerated in most of our patients. We observed mild BV related side effects in 5/16 children (mild proteinuria: n=2, mild hypertension: n=2, fatigue: n=1, epistaxis: n=1). No thrombosis or hemorrhage occurred, although all patients presented with a large tumor ranging in size from 2.5–8 cm in diameter. In one patient treatment had to be stopped due to hypertension, requiring antihypertensive treatment for 4 months. Another patient showed moderate proteinuria, and in one child wound healing was impaired. Conclusions: In contrast to reports in adult patients with high-grade gliomas no tumor hemorrhage was observed in any of our 16 pediatric patients. However, further prospective studies including more patients are warranted. P007*. CLINICAL AND RADIOLOGICAL CORRELATION IN CHILDREN WITH NEWLY DIAGNOSED INTRINSIC BRAIN STEM GLIOMAS TREATED WITH CONCURRENT AND ADJUVANT TEMOZOLOMIDE WITH RADIOTHERAPY: DATA FROM A PROSPECTIVE CLINICAL TRIAL R. Jalali, N. Raut, T. Gupta, B. Arora, P. Kurkure, D. Dutta, R. Sarin; Tata Memorial Hospital, Mumbai, India Background: To present outcome data and response evaluation in a prospective study of concurrent and adjuvant temozolomide (TMZ) with radiotherapy (RT) in children with diffuse intrinsic brain stem gliomas (DIBSG). Materials and Methods: Pediatric patients were prospectively treated with RT to a dose of 54 Gy/30 fractions and concurrent daily temozolomide TMZ (75 mg/m2). After RT, adjuvant TMZ (250 mg/m2) was given every 28 days up to a maximum of 12 cycles. Response was evaluated clinically and with MRI and FDG-PET scans. Results: Between March 2005 and November 2006, 20 newly diagnosed DIBSG patients (15 boys, 5 girls, median age 8 years) were accrued. At baseline pre-RT evaluation, 6 patients had no contrast enhancement on MRI. MR perfusion scan showed hyperperfusion on 13 and hypoperfusion on 7 patients. On MR Spectroscopy (MRS), 10 patients each had features of low-grade and high-grade gliomas. Among 11 patients with baseline PET scans, increased uptake was seen in 6. All 20 patients completed concurrent chemo-RT. One patient died at completion of RT. 8 patients completed 6, and 3 patients 12 cycles of adjuvant TMZ. Mean concurrent and adjuvant dose of TMZ was 65 mg and 174 mg, respectively. In concurrent RT+TMZ, thrombocytopenia of Gr-III/IV was seen in 3 and leukopenia in 2 patients. Gr-III/IV vomiting was seen in 07 patients requiring medication. Most patients (18) had grade-II skin toxicity. In adjuvant TMZ, 2 patients developed Gr-III/IV leukopenia and 1 patient Gr-IV thrombocytopenia. Mean overall survival (OS) was 10.39 months (range 1.7–22 months) and progression free survival (PFS) was 9 months (range 1.7–22.6 months). 16 patients lived for more than 6 months, 7 1 year, and 2 for 18 months. At last follow up, 17 patients (85%) have died due to progression and 3 patients (15%) are alive with stable disease. MRI diagnosis of HGG (p=0.001) had worse survival than low-grade glioma. MR perfusion showed significant correlation with survival (p=0.043). However, MRS (p=0.258) and PET scan uptake (p=0.911) of high-grade tumor did not show correlation with survival. Patients with neurological improvement after RT had significantly better survival (p=0.048) than those who did not. Conclusion: Temozolomide with RT has not yielded any improvement in outcome of DIBSG than already known. Patients diagnosed with hyperperfusion on MR have significantly worse survival. FDG-PET was poor in diagnosis of the grade of the tumor and response to treatment. P008. PRIMARY INTRACRANIAL TUMORS IN CHILDHOOD N. Balak, N. Isik, M. Efendioglu, M. Onoz, G. Silav, A. Yoruk, M. Celik, I. Elmaci; Göztepe Education and Research Hospital, Istanbul, Turkey Aim: The frequency of pediatric brain tumors is different from that of adults regarding the histopathology of tumors and their management. This study was conducted to reveal the most frequent pediatric tumors that were surgically treated in our hospital and discusses their management. Materials and Methods: The authors retrospectively investigated 55 child patients with histologically confirmed intracranial tumors (except one case of pons glioma which was diagnosed radiologically), who were operated on at Göztepe Education and Research Hospital in Istanbul between 1998 and 2008. Results: The mean age of the patients (21 males and 34 females) was 8 years (range: 3–16 years). Of the total 55 cases, 31 cases were supratentorial and 24 were infratentorial. The most frequent tumors were astrocytomas (21 patients), medulloblastomas (15 patients) and pituitary adenomas (7 patients). The less frequent tumors were meningioma, ependymoma, craniopharyngioma, dermoid cyst, and mesenchymal sarcoma. Surgery was performed in 54 patients. Early post-operative mortality was seen in 2 cases. In 7 patients, there were focal motor and/or cranial nerve deficits after surgery. However, they recovered functionally although tracheotomy and gastrostomy were necessary temporarily in these patients.. Twelve patients received adjuvant chemotherapy. One patient with a pons glioma received radiotherapy only. 20 out of total 55 cases were treated between 1998 and 2002, whereas 35 cases out of total 55 cases were treated between 2003 and 2008. Conclusion: The most frequent pediatric intracranial tumor was astrocytoma in our series. There was an increase in the number of patients in the second half of the 10-year period in this study. Postoperative morbidity included cranial nerve deficits and focal motor deficits. P009. LONG-TERM SURVIVAL OF A PEDIATRIC PATIENT WITH GLIOBLASTOMA MULTIFORME (GBM) FOLLOWING MULTIPLE TREATMENTS WITH CARMUSTINE (BCNU) WAFERS AND TEMOZOLOMIDE (TMZ) A. Ollero1, J. Marquez-Rivas2, G. Ramirez3, E. Quiroga3, J. Gimenez-Pando4, C. Segovia-Vergel3; 1Escuela Superior de Ingenieros, Sevilla, Spain, 2Servicios de Neurocirugia, Hospitales Universitarios Virgen del Rocio, Sevilla, Spain, 3Universidad de Sevilla, Sevilla, Spain, 4Hospitales Universitarios Virgen del Rocío, Sevilla, Spain Introduction: Despite standard treatment, malignant glioma has a very poor prognosis. Newer strategies incorporating local or systemic chemotherapy have been developed, and increasing evidence in the literature shows that these multimodal approaches could be of the increased benefit in the management of these patients. We present a case of long-term survival in a pediatric patient with GBM treated with a multimodal strategy including exeresis, local and subsequent oral chemotherapy, and re-treatment after relapse. Case Report: A 6-year-old male patient with a posterior temporal lobe lesion was admitted to our institution. Posterior temporal craniotomy and subtotal resection were performed, and a diagnosis of GBM was made. Two weeks later the patient was re-operated and intrasurgical, corticographically-guided, macroscopically complete exeresis was performed, during which 8 BCNU wafers were implanted. There were no relevant post-surgical complications and the patient began receiving fractionated radiotherapy (total, 50 Gy) with concomitant TMZ (60 mg/m2/day, days 1–5, every 28 days). The patient continued TMZ treatment for 18 months without incident, until a scheduled MRI scan revealed a local relapse. The patient underwent complete resection and histopathology confirmed GBM relapse; 4 BCNU wafers were implanted into the resection cavity. There were no relevant postsurgical complications, and the patient re-initiated TMZ for 24 months without disease progression. After 18 months of follow-up post-TMZ, and 5 years after the initial diagnosis the patient remains disease-free. Conclusion: Multimodal therapy is an option in the management of GBM. Our experience in this case shows that multimodal treatment with macroscopically complete resection, BCNU wafers, TMZ, and radiotherapy (for primary disease) both in first surgery and local relapse appears to be well-tolerated. There were no clinically significant complications associated with the multimodal approach. The use of BCNU wafers in combination with TMZ provides continuous anti-tumor activity immediately following resection. This may improve tumor control and provide a survival benefit. P010. OMMAYA RESERVOIRS FOR INTRATHECAL CHEMOTHERAPY IN CHILDREN WITH CENTRAL NERVOUS SYSTEM TUMORS: EXPERIENCE IN 58 CONSECUTIVE PATIENTS I. Slavc1, T. Czech2, M. Gruber-Olipitz1, A. Peyrl1, E. Minichmayr1, W. Dietrich2; 1Department of Pediatrics, Medical University of Vienna, Vienna, Austria, 2Department of Neurosurgery, Medical University of Vienna, Vienna, Austria The Ommaya reservoir facilitates repetitive delivery of drugs into the CSF and is a pharmacologically rational system for administering intrathecal chemotherapy. However, previous studies have found a rate of infection and other complications ranging from 4.8 to 19 %. Methods: Between 1992 and 2007, 58 patients aged 4 months to 18 years with various poor prognosis brain tumors received intrathecal chemotherapy via an Ommaya reservoir. All patients received perioperative antibiotic therapy. 2,213 chemotherapy administrations via the reservoir were performed amounting to a median of 35 deliveries per reservoir. Only personnel undergoing a special training were allowed to administer the intrathecal therapy. CSF cell counts and bacterial cultures were obtained at each use of the reservoir. Intravenous antibiotics were used generously in patients with increase of C-reactive protein (CRP) levels to avoid seeding of the reservoir during bacteremia. Results: There were no cases requiring reoperation for infection or malpositioning of the ventricular catheter. In one patient the trajectory of the intraventricular catheter required reassembly due to kinking at the burr hole edge. 35 (60%) of the patients are surviving a median of 4 ½ years (range 3 mo–13 ½ years) after reservoir placement. No late onset Ommaya reservoir infections occurred in any of the long-term survivors. Conclusion: Use of Ommaya reservoirs is safe in immunocompromised children with brain tumors if neurosurgeons experienced with the technique are implanting the device, physicians and nurses administering the drug undergo special training, and systemic antibiotics are used perioperatively and when CRP levels increase. P011*. LONG-TERM SURVIVORS OF A SYSTEMIC AND INTRAVENTRICULAR CHEMOTHERAPY WITH DEFERRED RADIOTHERAPY IN PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA A. Juergens1, H. Pels1, S. Rogowski1, H. Schulz2, H. Reichmann3, M. Vogt-Schaden4, I. G. H. Schmidt-Wolf5, U. Schlegel1; 1Ruhr-Universität Bochum, Bochum, Germany, 2University of Cologne, Cologne, Germany, 3University of Dresden, Dresden, Germany, 4University of Heidelberg, Heidelberg, Germany, 5University of Bonn, Bonn, Germany Objectives: To evaluate survival, quality of life and neurotoxic sequelae in long-term survivors with primary central nervous system lymphoma (PCNSL) after systemic and intraventricular chemotherapy with deferred radiotherapy. Patients and Methods: From 09/1995 to 12/2001, 65 patients with PCNSL (median age 62 years) were enrolled in a pilot/phase II study evaluating chemotherapy without radiotherapy; thirty patietns were younger than 60 years. A high-dose methotrexate (MTX) (cycles 1,2,4,5) and cytarabine (ara-C) (cycles 3,6) based systemic therapy (including dexamethasone, vinca-alkaloids, ifosfamide, and cyclophosphamide) was combined with intraventricular MTX, prednisolone, and ara-C. All living patients were contacted, a neurological examination, comprehensive neuropsychological testing, Quality of Life (QoL) Assessment (EORTC QLQ-C30 Version 3.0 and EORTC QLQ-BN20) and imaging were performed. Results: Twenty-one of 65 patients (32%) are alive. Of these, 17 patients were younger than 60 years at diagnosis, resulting in long-termsurvival rate of 17 of 30 patients (57%). Median follow up is 99.5 months (range, 70 to 147 months) in surviving patients. Seventeen/21 patients completed all investigations, in three patients test results are pending, one is lost to follow up. One patient is currently undergoing therapy for tumor relapse; one other patient developed a second malignoma (liposarcoma). In three patients, a pure extraneural relapse was diagnosed after 9, 31, and 40 months and showed complete remission to high-dose chemotherapy in all. There was no evidence of late onset neurotoxity nor compromise of therapy- or tumor-related QoL measures in any of the examined patients. Conclusions: Primary polychemotherapy based on high-dose MTX and ara-C is highly efficient in PCNSL. More than half of patients < 60 years can obviously be cured with this regimen without suffering from long term neurotoxic sequelae. P012. IMMUNOCHEMOTHERAPY WITH RITUXIMAB IN CONJUNCTION WITH BLOOD-BRAIN BARRIER DISRUPTION AND AN ICE REGIMEN FOR RELAPSED OR REFRACTORY PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMAS K. Mishima, T. Suzuki, N. Uemiya, J. Adachi, K. Wakiya, S. Ishihara, F. Yamane, S. Khoyama, M. Masao, R. Nishikawa; Saitama International Medical Center, Saitama Medical University, Saitama, Japan High-dose methotrexate (HD-MTX)–based chemotherapy with whole brain irradiation improves the prognosis of PCNSL, however up to 30% of patients are refractory to primary therapy and 60% relapse. Fewer than 50% of patients enter a second remission. Thus, novel treatment regimens for relapsed PCNSL are needed. As the majority of PCNSL are B-cell type expressing the CD20 antigen, treatment with the monoclonal antibody (mAb) rituximab might be reasonable. However, delivery of mAb to the brain would be limited by the blood-brain barrier (BBB). Osmotic BBB disruption (BBBD) is currently being used to increase the delivery of chemotherapeutic agents for the treatment of brain tumors. We hypothesize that BBBD would enhance deribery of mAb to the CNS. The activity of rituximab plus ifosfamide, cisplatin, and etopside (R-ICE) as salvage therapy in systemic lymphomas provides the rationale for our use of the R-ICE regimen in conjunction with BBBD. Here we report our experience with i.v. rituximab with BBBD followed by ICE-based chemotherapy in patients with relapsed or refractory PCNSL. Five patients who failed therapy with HD-MTX–based chemotherapy were treated with a regimen of rituximab with BBBD followed by ICE in a 28-day cycle. BBBD was performed with 20% mannitol infused through catheter placed into the artery of the tumor site selectively at a rate of 3ml per second for 30–60 seconds. ICE included ifosfamide 900 mg/m2/d, CDDP 20 mg/m2/d, and etoposide 60 mg/m2/d on days 1–5. Four patients had prior RT and had been pretreated heavily. The mean age was 50 years. Three complete remissions, one partial remission, and one stable disease were achieved. The median progression-free survival from first R-ICE/BBBD was 4 months. The major toxicity was grade 3–4 neutropenia (5/5) and grade 3–4 thrombocytopenia (2/5). Hematotoxicity was prolonged in an elderly patient. The preliminary data presented here suggest that R-ICE with BBBD is an effective second-line treatment in PCNSL and clinical trials are necessary to evaluate both the efficacy and long-term safety of this treatment. P013. MAINTENANCE THERAPY USING RITUXIMAB FOR PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA T. Ichikawa, H. Kambara, H. Kosaka, S. Inoue, K. Yoshida, M. Onishi, I. Date; Okayama University graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama City, Japan Objective: The addition of high-dose methotrexate (MTX) to radiation has improved disease control and survival in patients with primary central nervous system lymphoma (PCNSL). However, more than one half of patients eventually relapse, and uncontrolled PCNSL remains the primary cause of death. We designed a maintenance therapy using rituximab (anti-CD20 antibody) after induction of complete remission to suppress recurrence. Methods: Preradiation chemotherapy consisted of MTX 3.5 g/m2 for a total of three to five doses. Cyclophosphamide, doxorubicin, vincristine, and predonisone (CHOP) were given concomitantly with each cycle of systemic MTX. Chemotherapy was followed by 36–40 Gy of whole brain radiation. Older patients were given the option of deferring radiation after a discussion of potential risks and benefits. Within 3 months after induction of complete remission, patients received multiple courses of rituximab; each course consisted of rituximab 375 mg/m2 given weekly for 4 consecutive weeks. Each course was repeated every 3 months. Results: Nine patients with a median age of 65 years (range, 55 to 72 years) were included in this study between 2004 and 2007. Six patients were older than 65 years-old. Median follow-up period was 21 months (range, 18 to 38 months). All patients had histologic diagnosis of diffuse large B-cell lymphoma and positive immunohistochemical staining for anti-CD20 antibody. One patient died of recurrent disease, but 8 patients were alive (range, 18 to 38 months) and their Karnofsky performance status (KPS) was kept higher than 80. Eight patients experienced recurrence. The median time-to-recurrence was 15 months (range 6–34 months). No toxicity was seen in association with rituximab. Conclusions: In recurrent cases, tumor growth is often explosive, which may result in a delay of treatment. In this study, complete remission was achieved in all patients who had recurrence. Maintenance therapy with rituximab did not suppress recurrence rate, however, it might prolong time-to-recurrence and suppress tumor growth rate and eventually contribute to prolong overall survival. In older patients, deferring whole brain radiation by retreatment with high-dose MTX and maintenance with rituximab did not compromise overall survival but did reduce neurotoxicity. P014. IMAGING FEATURES IN PARENCHYMAL LYMPHOMATOUS MASSES IN BRAIN: PRIMARY CNS LYMPHOMA OR SYSTEMIC INVOLVEMENT OF THE BRAIN? M. Mut1, K. K. Oǧuz2, S. Ayhan3, F. Söylemezoǧlu4, M. Berker5; 1Hacettepe University Faculty of Medicine Dept. of Neurosurgery, Ankara, Turkey, 2Hacettepe University Faculty of Medicine, Ankara, Turkey, 3Hacettepe University Faculty of Medicine Dept. of Neurosurgery, Ankara, Turkey, 4Hacettepe University Faculty of Medicine Dept. of Pathology, Ankara, Turkey, 5Hacettepe University Faculty of Medicine Dept of Neurosurgery, Ankara, Turkey We sought to determine whether there is any differentiating imaging feature between primary (G1) and secondary (G2) central nervous system (CNS) lymphoma. CT, MR imaging including Gd enhanced series, and diffusion-weighted imaging (DWI) findings of 16 patients, of which 10 were primary and 6 were secondary CNS lymphoma were re-evaluated. Pathological subtype of the tumors were diffuse large B cell in all primary and systemic tumors except 2 (1 lymphoblastic and 1 Burkitt type). In all patients, the mass lesions were mildly hyperintense to white matter and hypointense in the background of profound edema on T2W imaging. In 7/16 patients lesions had focal T1 hyperintensities due to hemorrhage (6 in G1; 1 in G2) and the rest were hypointense to white matter and could not be differentiated from accompanying edema. An infiltrating lymphoma of butterfly pattern, i.e., transcallosal bifrontal involvement, were observed in two patients of G2 but none in G1. Two patients were of intravascular type of CNS lymphoma. One had focal hemorraghic masses with profound edema and another patient had enhancing periventricular lesions with stripes of T2-hypointense oriented as perivascular spaces. The lymphomatous lesions were hyperintense on DWI and of low ADC values in 10 of 16 patients (6 in G1, 4 in G2). There was no correlation between CT density values of the lesions and ADC values. Ten of 14 patients who had CT examinations (6/8 in G1, 3/5 in G2) showed increased HU values. In 5 patients a very infiltrative pattern was observed. In a background of profound vasogenic edema scattered T2-hypointense nodules and stripes oriented parallel to medullary veins suggesting perivascular infiltration was present. Four of these cases including one with intravascular subtype were diagnosed as primary CNS lymphoma. These T2-hypointense nodules and stripes enhanced markedly on postcontrast T1-weighted series. Lobulated masses with marked enhancement and fuzzy borders were observed in 5 patients, patchy and perivascular enhancement with small nodules in 5 patients, and enhancement with well-defined borders in 6 patients were determined. In all four patients with infratentorial involvement either brain stem or cerebellum was of primary CNS lymphoma group. The basal ganglia were involved in three patients in G1 and none in G2. As a conclusion, involvement of infratentorial structures and the basal ganglia, hemorrhagic lesions appreciated as T1 hyperintensity and T2-hypointense nodules and stripes probably showing perivenular infiltration and Gd enhancement along the venules have been shown in primary CNS lymphomas in this study. P015*. NITROSOUREA-BASED CHEMOTHERAPY FOR LOW-GRADE GLIOMAS FAILING INITIAL TREATMENT WITH TEMOZOLOMIDE M. A. Sierra del Rio, G. Kaloshi, F. Ducray, A. Idbaih, F. Laigle-Donadey, S. Taillibert, A. Omuro, M. Sanson, J. Y. Delattre, K. Hoang-Xuan; APHP, Department of Neurology Mazarin, Hôpital de la Pitié Salpêtrière, Paris, France Objective: To evaluate the activity of nitrosourea-based (NU) chemotherapy as salvage treatment in progressive low-grade glioma (LGG) previously treated with temozolomide (TMZ). Methods: Retrospective review of patients treated from 1999 to 2005 in a single institution and who met the following criteria: adults with histologically proven LGG, progressive disease after TMZ treatment, NU based chemotherapy as second line treatment, and absence of prior radiotherapy (RT). Response was assessed by MRI. Progression-free survival (PFS) and overall survival (OS) were measured by Kaplan-Meier methodology. Results: 30 out of 148 patients treated with TMZ as primary treatment during this period fulfilled the criteria. In most cases, NU (PCV or BCNU) as second line treatment was preferred to RT, because of the large size of the tumor and/or the initial chemosensitivity to TMZ. Median age was 46 years (range 30–81). Histological subtypes included 21 pure oligodendrogliomas and 9 diffuse astrocytomas and mixed gliomas. Seventeen tumors demonstrated a mild contrast enhancement on MRI. Three patients achieved an objective minor response (10%); 20 patients had a stable disease (67%) and 7 patients progressed (23%). Toxicity was mainly hematologic with a 17% rate of grade III-IV myelosuppression. Median PFS was 6.5 months (95% CI 3–11.months). Median OS from start of salvage treatment was 23.4 months (95% CI, 13–29 months). Tumors without contrast enhancement were significantly associated with a better prognosis both in terms of PFS (p=0.0003) and OS from start of NU (p=0.0006). The 1p/19q codeletion available for 15 patients was not predictive for objective response to salvage treatment but correlated with a better PFS (p=0.02). Conclusion: Salvage NU chemotherapy provide disappointing results in TMZ pretreated LGG, which should be treated in priority by conventional radiotherapy. P016. CONTINUOUS LOW-DOSE TEMOZOLOMIDE (50 MG/MQ 1 WEEK ON/1 WEEK OFF) IN THE TREATMENT OF LOW-GRADE GLIOMAS A. Pace, M. Maschio, B. Jandolo, C. M. Carapella; National Cancer Institute Regina Elena, Rome, Italy The role of chemotherapy in low-grade gliomas (LGG) is still under investigation. However, recent studies have reported an interesting activity of temozolomide chemotherapy with standard schedule in patients affected by LGG of different histology treated in different stage of disease. Low-grade gliomas present a peculiar pattern of growth due to their biology: LGG have only a small fraction of proliferating cells, and many authors suggested that a chronic administration of a low dose of chemotherapeutic agents may be more suitable for slow growing tumors respect a high cytotoxic dose. The aim of our protocol of study is to explore the activity of a low dose schedule of temozolomide (50 mg/mq) given for 1 week on and 1 week off, in newly diagnosed LGG requiring treatment for the presence of negative prognostic factors such as residual tumor after surgery or biopsy, age higher than 40 years, neurological deficits, or uncontrolled epilepsy. Previous chemotherapy or signs of anaplastic components, with the presence of enhancing areas at MRI, are considered exclusion criteria. Main objectives include evaluation of activity with therapeutic response rate, PFS at 12 and 24 months, and toxicity. At present, fourteen patients have been enrolled (6 grade II astrocytomas, and 8 oligos or mixed), and 167 cycles of chemotherapy have been delivered (median=12 courses). 1p-19q co-deletion was present in 9 cases. No hematological or gastro-digestive toxicity more than grade 1 has been reported. 14 patients are evaluable for objective response after first follow-up MRI examination with 4 minor responses (28%), and 10 stable disease. 5 patients (38%) presented partial or complete seizure control during treatment. 7 patients presented early progression (median PFS=7 months). Considering the high progression rate the study was stopped. Conclusions: Continuous administration of a low dose of temozolomide shows interesting activity with objective response and clinical benefit, but does not seem to prevent early progression in the treatment of newly diagnosed requiring treatment LGG. P017. RESPONSE OF INTRACRANIAL EPENDYMOMAS OF THE ADULT TO TEMOZOLOMIDE E. Laguzzi1, R. Rudà1, E. Trevisan1, D. Guarneri1, R. Pedersini2, R. Boccaletti3, R. Soffietti1; 1Neuro-Oncology Unit, Torino, Italy, 2Medical Oncology, Bolzano, Italy, 3Neurosurgery, Torino, Italy Introduction: The role of chemotherapy in the management of intracranial ependymomas is still controversial, and few data are available in the literature regarding adult patients. Preclinical studies have shown activity of temozolomide against tumor xenografts derived from ependymoma, and a case is reported of a recurrent intracranial ependymoma in remission 10 years after completing temozolomide chemotherapy. Patients and Methods: In this prospective study we evaluated the efficacy and toxicity of temozolomide in patients with a histological diagnosis of intracranial ependymoma (grade II or III according WHO) who recurred after standard treatments. Fourteen adult patients were treated between 1999 and 2008. All patients had a recurrence after surgery and radiotherapy, while 4 received also a first line chemotherapy without benefit. Histological diagnosis was anaplastic ependymoma in 11 patients and ependymoma in 3. All lesions were enhancing on pre-treatment MRI. Tumor location was supratentorial in 8, infratentorial in 5, and supra and infratentorial in 1 patient. Two patients had an associated leptomeningeal spread. Median age was 36 years (range 18–60), median KPS was 75 (range 50–90), and 12 patients had neurological symptoms. Temozolomide was given orally at 150–200 mg/m2 daily on day 1–5 in cycles of 28 days up to 18 cycles. A patient was shifted to an extended schedule (150 mg/m2 1 week on/1 week off) after two cycles. Response was evaluated according to Macdonald's criteria based on enhanced MRI of both brain and spine performed every 3 cycles. Results: We observed 2 complete responses, 4 partial responses, 2 minor responses, 4 stable disease, and 2 progressive disease, with a 43% response rate. PFS was 71% at 6 months and 36% at 12 months. Median survival was 19 months (range 3–90). All responding patients had a histological diagnosis of anaplastic ependymoma. In 7/8 responding patients, we observed a neurological improvement. Myelotoxicity was moderate and not cumulative. Conclusions: Temozolomide has some activity in ependymomas, particularly in the anaplastic variant, and even patients unresponsive to previous chemotherapeutic regimens can respond. These data need to be confirmed in larger series. P018. TANYCYTIC EPENDYMOMAS: A FIVE-CASE SERIES AND LITERATURE REVIEW A. Rodríguez-Hernández, A. Bollar, I. Arrese, M. Armendariz, P. Torres, E. Ramos, I. Ruiz, M. Arrazola, N. Samprón, E. Urculo; Hospital Donostia, San Sebastian, Spain Background: Tanycytic ependymoma (TE) is one of rarest histopathological variants of ependymoma. These tumors are usually found in the spinal cord. Supratentorial location is extremely rare. We report five cases of TE: three spinal cases, another one from the fourth ventricle, and an unusual one arising from the lateral ventricle. Reported Cases: From the three spinal cases, two were located on the most frequent site, affecting cervico-medullary junction and high cervical spinal cord. The third one affected the conus medullaris. A complete gross resection was performed in all of them, and no adjuvant treatment was added. One of the patients died 2 years after surgery because of a previously diagnosed leukemia. The other two patients are free of illness one and six years, respectively, after surgery. The patient with the fourth ventricle TE underwent surgery, getting macroscopical complete resection. After eight years, a medullary image suggesting recidiva appeared on MRI. She declined a new surgery, and one year later she keeps without major neurological deficit and the lesion has not grown on control MRIs. The fifth case was a TE located in the left lateral ventricle. A complete transcortical resection was performed and adjuvant radiotherapy was added. Conclusion: TE usually have a more benign course than other ependymomas. They have special affinity for the cervical spinal cord, being extremely rare the supratentorial location. Microscopically, they are characterized because of their spindly bipolar cells resembling tanycytes. As ependymal rosettes are typically absent and pseudorosettes only vaguely delineated, these lesions can be misdiagnosed as astrocytomas or even schwanomas. TE are low-grade gliomas, and that is why surgical resection and follow up are considered as optimal therapeutic management. Adjuvant radiotherapy in residual lesions remains controversial. P019. PREGNANCY MAY CHANGE THE BIOLOGICAL BEHAVIOR OF WHO GRADE II GLIOMA L. Taillandier1, J. Pallud2, R. Abdul Razak3, P. Barbarino-Monnier3, M. Baron4, L. Bauchet5, V. Bernier6, L. Capelle7, C. Carnin1, D. Fontaine8, P. Gatignol9, F. Guillet-May3, M. Leroy10, E. Mandonnet7, P. Peruzzi11, H. Duffau12; 1Unité de neurooncologie, Hopital central, Nancy, France, 2Département de neurochirurgie, Hôpital Sainte Anne, Paris, France, 3Maternité régionale, Clinique universitaire de gynécologie-obstétrique, Nancy, France, 4Département de radiothérapie, hôpital Jean Minjoz, CHU, Besançon, France, 5Département de neurochirurgie, Hôpital Gui de Chauliac, CHU, Montpellier, France, 6Département de radiothérapie, Centre A. Vautrin, Vandoeuvre les Nancy, France, 7département de Neurochirurgie, Hôpital de la Salpêtrière, Paris, France, 8Département de neurochirurgie, Centre hospitalier universitaire, Nice, France, 9Département de neuropsychologie, Hôpital de la Salpetrière, Paris, France, 10INSERM U678, UPMC, Paris, France, 11Département de neurochirurgie, Reims, France, 12Département de neurochirurgie, Hôpital Gui de Chaulliac, Montpellier, France The advances in the understanding of the natural history of WHO grade II gliomas, and consequently the optimization of their therapeutic management, has allowed an improvement of their prognosis. Therefore, more and more young women harboring a WHO grade II glioma now envision a pregnancy. However, relationships between gliomas and pregnancy are poorly known. We report 8 consecutives cases of pregnancies observed in the supra-tentorial hemispheric WHO grade II glioma database of our French glioma study group (REG/Réseau d'Etude des Gliomes). In these cases, the clinical behavior of the tumor clearly worsened in 6 of the 8 observed pregnancies. The clinical implications will be considered and the mechanisms underlying such interactions will be discussed. In such tumor, a pregnancy may reasonably be envisioned, but the benefit-to-risk ratio should be carefully weighted and argumented: the will to have a child versus the possible risks for the fetus and the mother, which depend on the oncological status. If a pregnancy is decided, we advise to perform a very close neurological follow-up with repeated control MRIs in addition to a rigorous obstetrical monitoring. P020. EBV INFECTION IN A PATIENT WITH A LOW-GRADE OLIGODENDROGLIOMA C. C. Herold-Mende1, B. Lemke1, M. Yousef1, R. Ahmadi1, C. Dictus1, I. Harting2, C. Hartmann3, P. Schnitzler4, A. Unterberg1; 1Department of Neurosurgery, University of Heidelberg, Germany, Heidelberg, Germany, 2Department of Neuroradiology, University of Heidelberg, Germany, Heidelberg, Germany, 3Department of Neuropathology, University of Heidelberg, Germany, Heidelberg, Germany, 4Hygiene Institute, Department of Virology, University of Heidelberg, Heidelberg, Germany Infections with neurotropic viruses such as simian virus 40 (SV40), JC virus (JCV), BK virus (BKV), human papilloma virus (HPV) and members of the herpes virus family including human cytomegalovirus (HCMV), herpes simplex virus (HSV), and Epstein-Barr virus (EBV) have been accused to play a role in growth of primary brain tumors. In immunodeficient patients, EBV-carrying B-lymphocytes seemed to be a possible source, but the possibility of direct infection of brain resident cells has not been ruled out yet. Here, we tested the appearance of neurotropic viruses. In one oligodendroglioma tissue we could verify an EBV infection. We describe results obtained from our study sample, the clinical course of the EBV-positive patient, and our attempt to analyze the real source of EBV-positive cells. DNA of 55 frozen brain tumor samples (gliomas, meningiomas) was isolated and tested by nested PCR analysis for the integration of viral sequences from the above mentioned neurotropic viruses. In one patient with an EBV infection of his low-grade oligodendroglioma sample, DNA derived from the tumor tissue, the corresponding tumor cell culture and the patient's blood were analyzed for an EBV sequence. Immunohistochemical staining was performed using antibodies directed against the EBV-specific protein LMP1. While HSV, HCMV, HPV, BKV, JCV, and SV40 were not detected in any of the tumor samples, we amplified a viral DNA sequence of the EBV-specific protein EBNA-2 in the tumor tissue of a 53-year-old patient suffering from low-grade oligodendroglioma who underwent neurosurgical tumor resection. High IgG titers against EBV were detected in the patient's serum, and the EBNA-2 sequence was amplified from the tumor tissue and blood cells but not from the corresponding cell culture. In line with these results, we did not detect any EBV-specific LMP1 protein expression in the patient's tumor tissue by immunohistochemical staining. Our data suggest that infection of brain tissue by neurotropic viruses is an extremely rare event and does not seem to play a significant role in the growth of primary brain tumors. For the only patient in our study sample with a confirmed EBV infection in his tumor tissue, we were the first to identify blood cells to be the real source of EBV while tumor cells were undoubtedly negative. Therefore, future studies should include an analysis of corresponding blood DNA in order to answer the question whether viral infections are involved in tumorigenesis. P021. PRIMARY LEPTOMENINGEAL ANAPLASTIC OLIGODENDROGLIOMA WITH A 1P36-19Q13 DELETION: REPORT OF A UNIQUE CASE SUCCESSFULLY TREATED WITH TEMOZOLOMIDE A. Michotte1, C. Chaskis2, B. Neyns3, A. Tyberghien4, M. Declerck5, I. Origer6, J. Sadones7, P. In 't Veld7; 1Dept of Pathology Universitair Ziekenhuis Brussel, Brussels, Belgium, 2Dept of Neurosurgery Universitair Ziekenhuis Brussel, Brussels, Belgium, 3Dept of Medical Oncology Universitair Ziekenhuis Brussel, Brussels, Belgium, 4Dept of Neurosurgery Hôpital St Jean Brussels, Brussels, Belgium, 5Dept of Neurology ASZ Aalst, Aalst, Belgium, 6Dept of Pathology Hôpital St Jean Brussels, Brussels, Belgium, 7Dept of Experimental Pathology Universitair Ziekenhuis Brussel, Brussels, Belgium Primary leptomeningeal oligodendroglioma has very rarely been reported. The tumor is thought to be derived from heterotopic nests of neuroglial tissue within the leptomeninges. The disease has always a fatal outcome within a few years even if in some rare cases a partial response has been observed to radiotherapy and chemotherapy. Diagnosis during life may be difficult, and sometimes definite diagnosis is made only at autopsy. In the literature only one case has been reported with a deletion of chromosome 1p. We report a 60-y-old man presenting with seizures. Brain MRI showed a diffuse right parieto-occipital subarachnoidal enhancing lesion without intraparenchymal extension. Pathological examination of the surgical specimen obtained by open biopsy revealed an anaplastic oligodendroglioma (WHO grade 3). Radiotherapy was planned but during the preparatory work-up a marked progression was observed on MRI with diffuse ipsilateral and contralateral subarachnoidal tumoral extension. MRI of the spine revealed multiple enhancing nodular intradural lesions spreading over the entire spinal cord. Because of the diffuse meningeal involvement no radiotherapy was considered. As molecular analysis using the FISH technique showed 1p36 and 19q13 deletions, we decided to treat the patient with temozolomide 150 mg/m2 for 5 days every 4 weeks. We observed a dramatic regression of the lesions on serial MRIs with no residual enhancement left after 6 cycles of chemotherapy. The patient showed a remarkable neurological recovery. To our knowledge this is the first report of a patient with a primary leptomeningeal anaplastic oligodendroglioma with diffuse spinal seeding bearing a 1p36/19q13 deletion. Our patient showed a remarkable and sustained clinical and radiological remission following temozolomide treatment. Our case illustrates that molecular analysis with a search for 1p/19q deletions should be performed in all cases of leptomeningeal gliomas to select those patients who might benefit from temozolomide chemotherapy. P022. THE RESULTS OF TEMOZOLOMIDE BASED MULTIDISCIPLINARY TREATMENT FOR THE PRIMARY MALIGNANT GLIOMAS OF SPINAL CORD: EXPERIENCE OF 6 CASES C. Kim, C. Park, J. Kim, I. Kim, H. Kim; Seoul National University College of Medicine, Seoul, Republic of Korea Purpose: Malignant gliomas of the spinal cord are very rare neoplasms with a dismal prognosis. Although temozolomide (TMZ) is a novel oral alkylating agent with demonstrated efficacy as first-line and second-line therapy for patients with intracranial high-grade astrocytic gliomas including glioblastoma (GBL), there is no evidence or report that it is also effective for primary malignant gliomas of the spinal cord. Authors experienced six cases of primary spinal cord malignant gliomas which have been treated with multidisciplinary treatment using TMZ, and this retrospective study has been performed to determine the efficacy of and to document the role of TMZ in these patients. This may be the first report concerning the results of TMZ with a relatively large number of primary malignant gliomas of the spinal cord. Patients and Methods: Six patients (21–54 years, median 40) were enrolled into this retrospective study from Dec 2003 to Jan 2008. Three patients were anaplastic astrocytoma (AA), 2 were anaplastic ependymoma (EPN), and one was primary spinal cord GBL. TMZ (75 mg/m2/d × 7 d/wk for the period of radiation therapy) was administered orally concomitant with fractionated radiotherapy followed by TMZ monotherapy (150–200 mg/m2/d × 5 days, every 28 days for more than six cycles) in one GBL patient, and TMZ was used as adjuvant therapy (150–200 mg/m2/d × 5 days, every 28 days for more than six cycles) in the other five cases after radiation therapy. Results: One patient with GBL died after concurrent chemoradiotherapy using TMZ and 6 cycles of TMZ chemotherapy at 17 months of diagnosis. In three AA patients, one died after 39 months, one who had recurrent tumor after 12 years after radiation therapy showed partial response state after 6 cycles of TMZ (10 months after recurrence), and one was stable now with ongoing TMZ chemotherapy. In one anaplastic EPN patient 12 cycles of TMZ chemotherapy was done after radiation therapy. The patient showed partial response and was clinically stable 18 months after diagnosis. In the other case it was progressed after radiation therapy followed by 2 cycles of TMZ and although second line chemotherapy was done he was dead 9 months after diagnosis. These results were relatively excellent ones compared with historical data or data on published papers. Non-hematologic toxicities such as fatigue and anorexia were mild in severity. The concomitant treatment phase or adjuvant chemotherapy showed grade 1 neutropenia and thrombocytopenia in 2 patients only. Conclusion: TMZ may be one promising chemotherapeutic agent for primary malignant gliomas of spinal cord even for anaplastic EPN as primary or second line therapy. Concurrent chemoradiotherapy using TMZ may be also positively taken into account for the initial treatment of spinal cord AA or GBL. Further investigation of a larger number of patients and randomized clinical trial are mandatory. P023. ACUTE AND CHRONIC HEMORRHAGE IN SPINAL MYXOPAPILLARY EPENDYMOMA—AN INDICATION FOR RADIOTHERAPY? P. A. Fenton, G. Sharpe; Southampton Oncology Centre, Southampton, United Kingdom Introduction: Myxopapillary ependymoma is a WHO Grade I variant of ependymoma which occurs in the lumbosacral region and is characterized by perivascular cuboidal cells with myxoid degeneration. Acute spinal subarachnoid hemorrhage (SAH) due to myxopapillary ependymoma has been described as a presenting feature. We present cases illustrating acute, recurrent, and chronic hemorrhage due to myxopapillary ependymoma and discuss the implications for management. Case Reports: Case 1: A 32-year-old man presented following thrombolysis for a myocardial infarction with paraparesis due to acute hemorrhage from a lumbosacral myxopapillary ependymoma. Following complete surgical resection he recovered good neurological function. Case 2: A 42-year-old man who had suffered episodes of acute spinal SAH from presumed neurofibromata over 20 years underwent surgery for progressive symptoms and was found to have multiple sites of metastatic myxopapillary ependymoma throughout the spinal canal. He was initially managed with surgery alone but subsequently received radiotherapy to an area of progressive disease with no further subsequent episodes of acute SAH. Case 3: A 36-year-old man underwent surgery and radiotherapy for a lumbosacral myxopapillary ependymoma. Despite no evidence of macroscopic residual disease he subsequently developed deafness, ataxia, and cognitive impairment due to superficial siderosis from chronic SAH. Discussion: Myxopapillary ependymoma is generally regarded as a slow-growing tumor with an excellent prognosis. Treatment is by complete resection—where possible—with adjuvant radiotherapy given to areas of macroscopic residual disease. Hemorrhage is recognized as a presenting feature but is less well known as a cause of chronic morbidity. The cases illustrate the hemorrhagic potential of myxopapillary ependymoma. Chronic subclinical hemorrhage from residual disease can lead to superficial siderosis and permanent neurocognitive impairment with substantial morbidity. Radiotherapy is effective at reducing vascularity and hemorrhage in other clinical contexts and should be considered following incomplete resection to both improve local control and minimize the risk of future hemorrhage. Conclusion: Patients with myxopapillary ependymoma are at risk of hemorrhage and long-term morbidity. Radiotherapy to residual or metastatic disease should be considered to minimize this risk and all patients should be monitored for signs of chronic hemorrhage. P024. INTRAMEDULLARY ASTROCYTOMA AND EPENDYMOMA—SURGICAL RESULTS AND CLINICAL OUTCOME C. A. Eroes, S. Zausinger, E. Uhl, J. Tonn, R. Goldbrunner; Klinikum Grosshadern, Neurosurgical Department, Munich, Germany Introduction: Clinical outcomes of patients with intramedullary tumors seem to depend on histology and extent of surgical resection. The aim of our study was to assess surgical results and the neurological outcome of these patients. Material and Methods: A total of 43 tumor resections was performed in 38 patients (27 ependymoma, 7 astrocytoma WHO °I, 4 astrocytoma WHO °II) between 1/2002 and 5/2006 under intraoperative electrophysiological monitoring, 29 in the ependymoma, and 14 in the astrocytoma group. For ependymomas mean tumor extension was 2.9 levels (range 1–10), and in astrocytomas was 3.7 levels (range 1–9). In case of multilevel approaches, we performed a laminoplasty with refixation of the incised lamina(e). Routine intraoperative ultrasound and postoperative MRT was done to evaluate complete tumor removal. Clinical outcome using the McCormick scale (McC 0, no deficit –5, completely dependent) was assessed before operation, one week and 6 months after surgery. Results: Complete tumor removal was achieved in 22/29 ependymomas and in 6/14 astocytomas, 76% and 43%, respectively. Recurrent tumor growth during follow-up (range 6–40 months) was noted in 2 astrocytoma patients and no ependymoma patients. Ependymoma patients showed an improvement of neurological function during follow-up: Median McC improved from 2 (95%CI: 0.29) to 1 (0.38) after 1 week and 1 (0.40) after 6 months. In astrocytomas, in only 4/14 cases patients (McC 1–2) improved slightly. However, McC scores remained unchanged: 2 (0.36) preoperatively, 2 (0.39), and 2 (0.43) postoperatively. No neurological deterioration was seen in these patients. Conclusion: In contrast to generally high resection rates and encouraging outcomes in ependymomas, favorable neurological outcomes in astrocytomas are achieved only by (1) using cautious intraoperatibe strategies and (2) in patients with good preoperative McC. Therefore, early admission for surgery instead of watchful waiting should be the strategy in these patients. P025. GANGLIOGLIOMA— CLINICAL STUDY ON 13 CASES E. Naydenov1, C. Tzekov1, K. Minkin1, O. Kalev2, D. Toncheva3, N. Mirchev1, V. Bussarsky1; 1Department of Neurosurgery, University Hospital “St. Ivan Rilski”, Sofia, Bulgaria, 2Department of Pathology, Medical University, Sofia, Bulgaria, 3Department of Medical Genetics, Medical University, Sofia, Bulgaria Ganglioglioma is a rare type of central nervous system (CNS) tumors occurring most frequently in children and young adults. In this report we analyze thirteen cases of CNS ganglioglioma treated in our institution during the period 2003–2007. During the last five years, 699 patients having astro- and/or oligodendroglial CNS tumors were operated on in the Department of Neurosurgery at University Hospital “St. Ivan Rilski,” Sofia. Ganglioglioma occurred in 13 (1.86%) of them. The group consisted of 7 (53.8%) male and 6 (46.2%) female patients. The mean age of the patients was 23 years (from 4 to 74 years). The histological grade of gangliogliomas was as follow: grade I in 2 (15.4%) cases, grade II in 8 cases (61.5%), and grade III in 3 cases (23.1%). During the study period, only one patient necessitated second intervention because of tumor recurrence and anaplastic progression—a 36-year-old woman with coexisted Turner syndrome. Despite the fact that most gangliogliomas show benign clinical behavior and long-term survival rate, in some cases anaplastic progression may be seen. Further studies on a larger number of patients are needed to find the appropriate treatment strategies in these cases. P026. PERIPHERAL PRIMITIVE NEUROECTODERMAL TUMORS:A RETROSPECTIVE ANALYSIS OF 40 PATIENTS Y. Xia, Q. Liu, Z. Liu, Z. Chen; Sun Yatsen University Cancer Center, Guangzhou, China Objective: Peripheral primitive neuroectodermal tumor (pPNET) is a kind of highly malignant tumor, and researches on the tumors are rare. This study was to investigate the clinical characteristics, treatment, and prognostic factors of pPNET, and thus to explore the treatment principle and efficacy of the treatment. Methods: Clinical data of 40 pPNET patients, treated in Cancer Center, Sun Yat-Sen University, from 1997 to 2007, were analyzed retrospectively. Cumulative survival rate was analyzed by the Kaplan-Meier method. The log-rank test was applied to compare survival rates. Results: Of 40 patients, 23 received multimodality treatment, 14 received only surgery or chemotherapy, and 3 did not have any anticancer therapy. The median survival time was 23 months. The 1-, 2-, and 5-year overall survival (OS) rates of the 40 patients were 67.7%, 49.9%, 41.6%, respectively. Five-year OS was 57.9% in patients who received multimodality treatment, 13.1% for the rest (P=0.000); 25.1% in those with tumor size ⩾10cm, 48.5% in those with tumor size <10cm (P=0.028); 50.8% in those who received complete resection, 41.7% in those who underwent incomplete resection, 27.5% in those who received no surgery (P=0.048); and 45.9% in those with nonmetastasis, 35.7% in those with metastasis(P=0.424). Conclusion: Based on our experience and a review of the literature, we concluded that multimodality treatment is the main treatment of peripheral primitive neuroectodermal tumors. Tumor size greater than 10 cm, complete resection, and metastasis are prognostic factors for survival. P027. CEREBRAL ASTROBLASTOMA: ANALYSIS OF 6 CASES AND REVIEW OF THE LITERATURE M. Salvati1, C. Brogna1, A. d'Elia1, A. Melone1, J. Lenzi1, A. Frati1, A. Raco1, A. Santoro1, F. Giangaspero1,2, R. Delfini1; 1Neuroscience-Neurosurgery Department, Sapienza University, Rome, Italy, 2Neurosurgery Department, INM Neuromed IRCCS, Pozzilli, Isernia, Italy Background: Astroblastoma is one of the rarest tumors of the CNS whose classification, histogenesis, diagnosis, and therapeutic management are still being debated. The typical histopathological appearance is the perivascular, astroblastic pseudorosette, which is, however, present in other CNS tumors. Although it has intermediate features between astrocytomas and ependymomas, observations of a particular cytogenetic profile and clinical behaviour make it seem more and more likely that astroblastoma is a single entity. To clarify the clinical, radiological, histopathological, prognostic, and therapeutic characteristics, which have been treated only recently and not well established yet, six cases of histologically proven astroblastoma were retrospectively analyzed playing special attention to therapeutic remarks. Materials and Methods: Between 1996 and 2005, six patients with histologically proven cerebral astroblastoma were surgically treated at the Department of Neurosciences-Neurosurgery of Rome Sapienza University. In three cases the lesion was a low-grade astroblastoma, high-grade in the other three. Results: Median age of the six patients was 36 years. The time to diagnosis ranged from one week to 18 months. Surgical removal was total in four cases, subtotal in two. All patients received radiotherapy; two also had chemotherapy with temozolomide (TMZ). The three patients with low-grade astroblastoma are still alive today after a follow-up of 2, 5, and 19 years respectively. Of the three patients with high-grade lesions, one is still alive after a 7-year follow-up, while the other two survived for 17 months (progression time 15 months) and 35 months (progression-reoperation time 23 months) respectively. Conclusions: Radical surgical resection appears to be the treatment of choice for astroblastoma. Radiotherapy may play an adjuvant role in the treatment of high-grade lesions. The role of chemotherapy is very debatable, and we advocate the use of a safe adjuvant chemotherapeutic regimen with TMZ, especially for the high-grade astroblastoma cases. P028. PARAGANGLIOMAS OF THE HEAD AND NECK: A TREATMENT OPTION WITH CYBERKNIFE RADIOSURGERY L. Fariselli1, I. Milanesi1, M. Possanzini2, L. Brait3, L. Bianchi3; 1National Neurological Institute, Milan, Italy, 2Centro diagnostico italiano, Milan, Italy, 3Centro diagnostico italiano, Milan, Italy, Objective: Paragangliomas represent rare tumors of neural crest origin. They are highly vascular neoplasms and in the majority of cases are benign. Traditionally they have been treated by surgery, embolization, and/or external beam radiotherapy. Unfortunately these therapies are charged by the risk of high morbidity and mortality. Stereotactic radiosurgery could play a relevant role as a therapeutic approach: the aim of this study is to evaluate the acute effects and efficacy in term of local control using radiosurgery. Methods: Between August 2004 and December 2007, 9 patients, 8 with jugular glomus paraganglioma and 1 with carotid paraganglioma, have been referred to our Cyberknife center: in four cases patients were undergone to partial excision; no patients have had previous radiation therapy. The most common presenting symptom was conductive hearing loss, pulsatile tinnitus, and dysphagia, except for one patient who presented hypertension crisis. The patient with carotid glomus tumor had postoperative weakness of cranial nerves X, IX. Tumor volume ranged from 1602 mm3 to 12782 mm3 (median 5848 mm3) The delineation of the target was based on the integration of images from TC scan fused with RMN: the planning target volume was defined as the radiographic tumor volume with no margin. The tumor dose was at 11 to 13 Gy (mean 12.5 Gy) in single fraction for 8 patients (reference isodose 72–83%), and one patient received staged radiosurgery (total dose 24 Gy in 3 fractions). Results: The mean follow-up was 20 months. One patient died and thus was lost to follow-up. All patients have showed tumor stabilization. In two patients transient vertigo occurred, and one patient had headache with complete resolution three months after treatment. All patients demonstrated neurological stability. No cranial nerve palsies arose or deteriorated. Conclusion: Stereotactic radiosurgery appears to be both safe and effective in the treatment of glomus tumors. Long-term complications remain to be studied, and despite our preliminary results it is prudent to be cautious about tumor local control. Important prerequisites for good results are CT and MRI image fusions to correctly identify the PTV, and inverse planning to obtain the best conforming dose with minimal treatment delivery errors. P029. CRANIOFACIAL TUMORS: THE OPERATION AND RECONSTRUCTION A. I. V. A. Zaytsev; Hertzen Cancer Research Institute, Moscow, Russian Federation Introduction: The skull base reconstruction is a very important procedure in the cases of radical resection of skull base tumors. Materials and Methods: We presented 72 patients (male 40, female 32), aged 3.5 to 76 years, with skull base tumors extending into the orbits and paranasal sinuses (benign 45, malignant 27). All these lesions were divided into 3 groups. I group: the midline lesions (42 cases) included defects of ethmoid and sphenoid sinuses, frontal sinuses, and medial parts of maxillary sinuses. II group: the lateral lesions involved lateral parts of frontal sinus, upper-lateral parts of maxillary sinus as lateral skull base defects (19 cases). III group: combined skull base defects included both medial and lateral defects with widely opened paranasal sinuses and nasopharynx. (11 cases). Results and Conclusions: It is important to emphasize that the reconstruction with a periosteum flap from the frontoparietal area should be preferred in midline defects, a temporalis muscle flap with adjusted periosteum- in lateral defects. The reconstruction with autograft using microsurgery technique (m. latissimus dorsi flap, m. pectoralis, combined flap using m. pectoralis and m. abdominalis rectus musculocutaneous flap, omentus, m. latissimus dorsi with split-rib grafts) is indicated in case of combined defects. It was observed that two patients had nasal cerebrospinal fluid leak which resolved after continuous lumbar drainage. Preoperative planning of optimal method of closure of skull base defect depends on location and expansion of skull base tumor. P030. SURGICAL TREATMENT OF LACRYMAL GLAND TUMORS C. Tzekov1, E. Naydenov1, S. Cherninkova2, N. Mirchev1, K. Minkin1, Y. Enchev1; 1Department of Neurosurgery, University Hospital St. Ivan Rilski, Sofia, Bulgaria, 2Department of Neurology, University Hospital Alexandrovska, Sofia, Bulgaria The lacrymal gland tumors are relatively rare. Specific neurosurgical approaches are needed in some cases with intracranial expansion. Subjects of the study were patients having different type of lacrymal gland tumors surgically treated in the Department of Neurosurgery at University Hospital St. Ivan Rilski, Sofia during the period 1998–2007. The studied group consisted of 14 patients, 6 (42.9%) males and 8 (57.1%) females. The mean age of the patients was 41 years. The preoperative diagnosis was made using neuroophthalmological evaluation and neuroimaging procedures. All patients were operated on. Total excision of the tumor on the first stage was achieved in 12 (85.7%) cases, subtotal in 2 (14.3%) of them. The histological type of the tumor was as follows—adenoma in 3 (21.4%) cases, tumor mixtus in 4 (28.6%), carcinoma in 7 (50.0%). Five patients were reoperated on. In two of them orbital exenteration was performed. The lacrymal gland tumor treatment is mainly surgical with two main aims—radical excision of the lesion and vision preservation. The prognosis in these cases depends on histological type and tumor expansion at the time of diagnosis. P031. SURGERY OF ORBITAL TUMORS T. N. Eftimov, T. Shamov, A. Petkov; Military Medical Academy, Sofia, Sofia, Bulgaria. Objective: The aim of this study was to determine the surgical frequency of the intraorbital tumors, to analyze the most frequent clinical symptoms, to define the diagnostic role of neuroimaging methods, to specify the optimal neurosurgical treatment, and to analyze the results of operative management and most frequent postoperative complications. Materials and Methods: The study included 38 patients with orbital tumors who were admitted in the period 2000–2007. Thirty-six patients with primary intraorbital tumors were operated on. In 2 patients reoperative interventions were done by reason of residual tumor or tumor recurrence. Different surgical approaches were used according to tumor localization. Results: The extraconal tumors were prevalent. The most frequent clinical symptom was exophthalmia (89%), followed by diplopia (45%), bulb dislocation (26%), and visual disturbances (15%). According to histopathological determination, mucocele was found in 29%, dermoid cysts in 11%, lacrimal gland tumors in 8%, neurinomas in 8%, and lymphomas in 8%, etc. Magnetic resonance imaging has some disadvantages as a diagnostic method. In 43% of operated patients the lateral orbitotomy was done. Transitory postoperative complications were assessed in 25% of patients and in 14% of them the complications were permanent. Conclusions: The choice of surgical approach was defined according to tumor localization, size of the tumor, expected histopathological results, and results of neuro-ophtalmologic investigation. The right surgical approach and precise surgical technique decrease the frequency of postoperative complications. P032*. SUPRATENTORIAL VENTRICULAR TUMORS: A SURGICAL PERSPECTIVE S. I. Florian1, C. I. Abrudan1, A. Oslobanu1, Z. Andrasoni2; 1Neurosurgical Department of the University of Medicine and Pharmacy Iuliu Hatieganu, Neurosurgical Department, Cluj-Napoca County Hospital, Cluj-Napoca, Romania, 2Neurosurgical Department, Cluj-Napoca County Hospital, Cluj-Napoca, Romania Background: Brain tumors located in the ventricles represent 1.4% from all brain tumors. From a surgical point of view, the profound location and the necessity to intersect normal brain tissue with minimal functional alteration, the abundant vascularisation that interferes with normal vasculature, and the large dimensions of tumors, altogether represent problems that must be solved by neurosurgeon. Patients and Methods: We retrospectively present the indications, results, outcomes, and surgical treatment of 39 patients diagnosed with intraventricular supratentorial tumors. Results: Supratentorial intraventricular tumors represent 2.8% of 1,376 intracranial tumors operated on by the author between January 2000 and December 2007. From a surgical perspective, our strategy is a transcortical approach for tumors located in the lateral ventricle, for tumors located in the third ventricle transcallosal, and subfrontal trans-laminaterminalis approaches, if there is an intraventricular extension from a sellar tumor. VP-shunt is reserved only for cases of persistence of symptomatic hydrocephalus after tumor removal, or for cases in which the direct approach was denied or considered deleterious related to neurological status of the patient. Temporary EVD (4 to 5 postoperative days) is frequently used after transcallosal or transcortical approach. By this protocol we obtained a total removal in 84.6% of the cases. Recurrences occurred in 12% of the cases. Pathological examination revealed features such as 23% astrocitomas, 18% malignant gliomas, 12.8% ependimomas and craniopharingyomas, 5% cholloid cysts and neurocytomas, and 2.5% metastases, meningiomas, gangliolglyomas, and pituitary adenomas. Postoperative complications consisted of persistent symptomatic hydrocephalus (5 cases) and intraventricular bleeding and/or edema in four cases. The surgical results were GOS 5 and 4 in 30 cases, 7 cases with GOS 3, and 2 deceased (one case with multiple metastases and one case with pulmonary embolism). Conclusions: Complete neuroimagistic evaluation, a proper surgical approach, progressive debulking of tumor with great attention to preserve normal vasculature, and EVD in order to prevent acute hydrocephalus are the key points for good surgical results. P033. PURE ENDOSCOPIC ENDONASAL RESECTION OF THE SELLA LESIONS D. Netuka, V. Masopust, V. Beneš; Department of Neurosurgery, Prague, Czech Republic Introduction: Endoscopic resection of sella lesions has become more frequently performed in recent years. Our initial experience is evaluated. Methods: Since April 2006 we started to perform endoscopic sella surgery. Till April 2007, altogether 39 patients with either pituitary adenoma or craniopharyngeoma were operated on with this technique. This group consisted of 24 women and 15 men. Three patients had STH hormone hypersecretion and 4 had ACTH hypersecretion. Altogether, 26 patients had bitemporal hemianopsia caused by compression of the chiasm. Headaches lead in six cases to MRI finding of pituitary adenoma which was reaching to chiasm but not yet causing visual field deficit. Results: Pituitary adenoma was resected in 37 cases and in two cases craniopharyngeoma. There was no 30-day morbidity and mortality in this small series. In one case redo surgery was performed due to refractery postoperative CSF leak. In one case, postoperative nasal packing was needed due to nasal bleeding. Normalization of hormone levels was reached in three of four cases of ACTH hypersecretion. In two cases, STH decrease was sufficient but was not in one other; residuum of adenoma was disclosed on postoprative MRI and the patient prefered LGK treatment as the second step procedure. Visual field deficit improved in 19 patients (73%), and remained stable in 7 patients. The mean postoperative in-hospital stay was 4.4 days. All patients found postoperative comfort as very good and suffered minimal pain. Conclusions: Endoscopic resection of sella lesions is a feasible technique with a relative steep learning curve. In-hospital stay was shortened in this group of patients compared to in-hospital stay of patients who formerly underwent sublabial paraseptal resection. The postoperative comfort was enhanced, and all patients tolerated the surgery and postoperative course very well. P034. TRANSORAL AND TRANSSPHENOIDAL APPROACHES FOR REMOVAL OF CRANIOSPINAL TUMORS N. Mirchev, V. Bussarsky, K. Romansky, A. Hadjijanev, M. Marinov, K. Georgiev, Y. Enchev, G. Kunin, C. Tzekov, E. Naidenov; St. Ivan Rilsky Hospital, Sofia, Bulgaria A retrospective analysis of the surgical treatment and results of 20 patients with benign and malignant craniospinal tumors operated on during the period 1992–2007 at the Department of Neurosurgery, Medical University-Sofia, Bulgaria was performed. The aim of the analysis was to assess the factors affecting choice of minimal invasive approach, operative radicality, and outcome. The mean age of the patients was 45.2 years. The male to female ratio was 1:1.5. The most frequent neurological symptoms were intracranial hypertension, qudriparesis, bulbar palsy, alternate syndromes, hydrocephalus, and spinal nerves palsy. Preoperative imaging revealed extradural tumors in 19 cases and intra/extradural tumor in 1 case. In 13 patients the tumor origin was cranial with secondary spreading into the spinal area, and 7 patients had primary spinal tumor localization followed by cranial spreading. In this group of patients we have observed 1 meningioma, 1 myeloma, 5 metastasis, 12 chordoma, and 1 sarcoma. In our group of 20 patients we made 34 operations. We performed 30 cytoreductive operations and because of craniocervical instability, we made occipitospinodesis in 4 cases. We used a transoral approach in 22 cytoreductive operations, and a transsphenoidal, endonasal approach was employed in 8 operations. Complete tumor removal was achieved in 1 case (3.33%), subtotal resection in 15 cases (50%), partial tumor resection in 10 of the cases (33.33%), and biopsy in 2 cases (6.66%). The most common operative complications were: CSF leak in 1 case (3.33%), brainstem edema in 3 cases (10%), and operative mortality in 3.33%. The 5-year follow-up showed good recovery in 42%, moderate disabling in 35%, severe disabling in 13%, vegetative state in 4%, and death of 6%. We conclude that early minimal invasive decompressive surgery facilitates neurological recovery by preserving the existing neurological function. Transoral and endonasal, transsphenoidal approaches are an effective surgical method for direct decompression in patients with irreducible ventral midline extradural compressive tumors of craniospinal area. P035. COMPARISON BETWEEN THE TRANSCRANIAL APPROACH AND THE EXTENDED TRANSSPHENOIDAL APPROACH FOR THE TUBERCULUM SELLAE MENINGIOMAS: INTERHEMISPHERIC APPROACH VS. TRANSSPHENOIDAL-TRANSTUBERCULUM SELLAE APPROACH T. Kato; Hakodate Central Hospital, Hakodate, Japan Objectives: The tuberculum sellae meningiomas are usually removed using various transcranial approaches. The so-called extended transsphenoial approach is a modified transsphenoidal procedure for some lesions around the sella turcica, anteriorly to the tuberculum sellae and the planum sphenoidale, laterally to the cavernous sinus, and posteroinferiorly to the clivus. The author approaches the supradiaphragmatic tumors though the tuberculum sellae, termed “transsphenoidal-transtuberculum sellae approach,” even for some tuberculum sellae meningiomas. This paper describes some characteristics and indications between the transsphenoidal-transtuberculum sellae approach and the interhemispheric approach for the tuberculum sellae meningiomas. Materials and Methods: The operative approach was selected by three indexes: (1) development of the sphenoid sinus, (2) anterior and lateral extension of the tumor, (3) tumor extension into the optic canal. Utilizing the transsphenoidal-transtuberculum sellae approach since 1994, 25 supradiaphragmatic tumors including 3 tuberculum sellae meningiomas have been removed, and two tuberculum sellae meningiomas were resected by the interhemispheric approach because of the broad base and the intraoptic canalicular extension of the tumor. Results: Utilizing the transsphenoidal-transtuberculum sellae approach, total resections were performed for two meningiomas and subtotal resection was achieved in one case. The other two meningiomas were totally removed using the interhemispheric approach. In the transsphenoidal-transtuberculum sellae approach, the operative complications were the injury of the anterior cerebral artery during resection of the tumor, which was wrapped for hemostasis using fibrin sealant, and the postoperative pneumocephalus. Whereas in the interhemispheric approach, unilateral olfactory nerve injury and asymptomatic unilateral frontal contusion occurred in both cases. The mean operative time was 5h 52m in the transsphenoidal-transtuberculum sellae approach and 8h 38m in the the interhemispheric approach, and the mean hospitalization was 32.7 days in the former and 20 days in the latter. Conclusions: The transsphenoidal-transtuberculum sellae approach for accessing small tuberculum sellae meningiomas is a useful procedure as a less invasive technique with short operative time compared with the interhemispheric approach, although it requires care during incision between the tumor and the surrounding structures. P036. THE SUPRAORBITAL MININVASIVE APPROACH FOR THE REMOVAL OF ANTERIOR CRANIAL FOSSA MENINGIOMAS A. Pompili1, M. Giovannetti2, S. Telera1, A. Vidiri3, E. Occhipinti1; 1Neurosurgery, Regina Elena National Cancer Institute, Roma, Italy, 2Anesthesiology. Regina Elena National Cancer Institute, Roma, Italy, 3Radiology and Diagnostic Imaging, Regina Elena National Cancer Institute, Roma, Italy Introduction: Traditionally, the tumors of the anterior cranial fossa and/or sellar area, except pituitary adenomas, are approached through a subfrontal or transylvian approach. The latter is the most popular for the sellar area, after the technique described by Yasargil in the '70s. Materials and Methods: We used the transylvian approach routinely over the years. In selected cases, since 4 years, we used the supraorbital mininvasive approach according to Perneczky. We operated on 18 patients with meningioma: 13 of the tuberculum sellae, 5 of the etmoidal planum. There were 3 males and 15 females. Age ranged from 39–81, average 57. In 4/5 of the patients with planum ethmoidalis tumor the diagnosis was done at MRI or CT made for other reasons; the same happened only in one of those with tuberculum sellae meningioma. 12/13 of these had severe preoperative visual impairment. Results: The anatomical operative view was excellent. We had some difficulties using large instruments. However, it was rather easy to become accustomed to work through a limited bone flap. Head position, CSF peroperative spinal drain, and excellent anesthesia are essential for the approach. The frontal lobe should not be retracted but gently reclined. One patient with tuberculum sellae meningioma died due to the sequelae of an internal carotid artery intraoperative lesion. Another had transient right hemiparesis. 4 had postoperative anosmia on the side of the approach. Out of the 12 patients with visual deficit, 11 were evaluated (1 died): 9 improved, 2 worsened: one had subclinoidal implant of the tumor, another was a recurrent case where adhesions between optic nerve and tumor were tenacious. All the patients with planum tumors did well. The only symptomatic one had her ataxia and confusional syndrome improved. Postoperative MRI, done at 3–6 months postoperatively, did not show any sign of brain contusion. None of our patients had seizures and at present needs any anticonvulsivant medication. Cosmetic results were excellent, therefore, there is no postoperative retraction of the temporal muscle. Conclusions: In our minds, these are the major advantages of the technique. The major clinical disadvantage may be a postoperative olfactive disturbance, because in some cases it has been impossible for us to spare the olfactory tract of the side of the approach. This is an elegant and effective alternative to the subfrontal and pterional ones. Its limits may be the dimensions of the tumor if combined with fibrous or hard consistency. P037. MINI-INVASIVE UNILATERAL APPROACH FOR THE REMOVAL OF INTRADURAL EXTRAMEDULLARY TUMORS A. Pompili1, F. Caroli2, F. Cattani3, M. Giovannetti4, L. Raus5, S. Telera6, A. Vidiri7, E. Occhipinti5; 1Neurosurgery, Regina Elena National Cancer Institute, Roma, Italy, 2Neurosurgery, Regina Elena National Cancer Institute, Roma, Italy, 3Neurosurgery, Regina Elena National Cancer Institute, Roma, Italy., Roma, Italy, 4Anesthesiology, Regina Elena National Cancer Institute, Roma, Italy, Roma, Italy, 5Neurosurgery, Regina Elena» National Cancer Institute, Roma, Italy, Roma, Italy, 6Neurosurgery, Regina Elena National Cancer Institute, Roma, Italy, 7Radiology and Diagnostic Imaging, Regina Elena National Cancer Institute, Roma, Italy, Roma, Italy Introduction: Spinal intradural tumors are generally removed by uni- or multilevel laminectomy with midline dural incision. Delayed post-operative kyphosis and spinal instability, which occurs in 6% of the patients, may be reduced by a more conservative unilateral microsurgery, sparing bilateral damage. Methods: 49 patients, 34 with neurinoma, 8 meningioma, 3 caudal ependymoma, 2 conus medullaris dermoid tumor, and 1 each dorsal intramedullary melanoma and cervical intramedullary metastasis were operated on between June 2000 and June 2007. One had 3 lumbar tumors and required two operations because of MRI misinterpretation, one had 2 dorsal meningiomas removed during the same operation, and 2 patients had dumbbell neurinoma. 1 neurinoma and 2 meningiomas were located at the C1–C2 level. Surgery was performed in the prone position with a unilateral approach. The extension of the laminectomy was kept generally to one level, having care to remove all the ligamentum flavum. When necessary, it was extended cranio-caudally for 1.5–2 cm. The dura was opened paramedially and the tumor dissected and removed either “en bloc,” when smaller than 2 cm, or piecemeal. In one patient, it was deemed necessary to enlarge the exposure to a traditional approach because of concomitant severe stenosis and huge tumor. Dural closure is done with 5–0 or 6–0 stitches. Tumor dimensions ranged from 1.2 to 2.8 cm in maximum diameter. The patient that required the extension of the approach had a multilobulated neurofibroma of 6 cm. Results: All the patients were mobilized on day 2–3 and discharged on day 4–5. No important complications due to the technique were observed; post-operative pain was minimal. One patient had a pseudomeningocele under the muscular plane, that did not require reoperation. Plain X-ray films showed that none of them had kyphosis and/or instability 3 months post-op. Overall neurological results were good. Conclusions: Hospital stay may be reduced and stability preserved with an appropriate microsurgical mini-invasive technique. In selected patients it can be used also for small intramedullary lesions, although in our cases it was done because of preoperative misdiagnosis. In case of operative difficulty it can be converted rapidly into a traditional approach: only one case in the present series. P038. SURGICAL TREATMENT OF DRUG-RESISTANT TEMPORAL LOBE EPILEPSY CAUSED BY INTRACEREBRAL TUMORS B. Y. Bondar, V. Chernenkov, I. Serbinenko, M. Posokhov, A. Pykhtin, A. Chernenkov, O. Gorbunov, V. Makarov, A. Mihaylov; Institute of Neurology, Psychiatry and Narcology AMS of Ukraine, Kharkov, Ukraine Background: Brain tumors can be a reason of medically intractable temporal lobe epilepsy (TLE). Intralobar localization of new growth influences epileptogenesis, features of diagnostics, and surgical treatment. Methods: During 2004–2007, 7 adult patients were operated concerning intracerebral brain tumors, combining with pharmacoresisting TLE. In all cases TLE was the main or unique clinical display of disease on an extent from 6 months to 18 years. Used: EEG, MRI, ECoG, and EsCoG. In 5 supervisions gliomas were small, localized directly in temporomedial departments, and coincided with the hearth of epileptic activity. Operative intervention was limited to the resection of new growth and perifocal area within the limits of the temporomedial structures. In one supervision, large (5 × 6 cm) astrocytoma II was localized in the overhead and middle departments of the right temporal lobe and spread on the insula but had secondary influence on temporomedial structures with formation in hippocampus, the limited focus of destruction. All of the pathologically changed area of the temporal lobe was totally removed. 2 patients with TLE had large astrocytomas, without a germination in a temporal lobe. In these cases low-grade tumors were removed totally without surgical manipulations on temporal structures. Histological results: astrocytoma 4 cases, ganglioma/gangliocytoma 1, and oligodendroglioma 2. Finding: Surgical mortality was zero. The attacks of epilepsy in all cases were stopped. Two patients undergoing surgical resection in insula may have transient postoperative motor and speech deficits, which recover during few weeks or months. Conclusion: Intracerebral low-grade tumors of temporal localization can be a principal cause of pharmacoresistant focal temporal epilepsy. The mechanisms involving epileptogenesis temporal mesenchymal structures are different. In these cases radical open surgical interventions are highly effective ways of treating TLE. P039. COMPLICATIONS OF GLIOMA SURGERY AND ITS INFLUENCE ON PATIENT PROGNOSIS D. Netuka, F. Kramar, M. Mohapl; Department of Neurosurgery, Prague, Czech Republic Introduction: The morbidity/mortality of glioma surgery varies between 5–30% according to different studies. Tumor localization, type of tumor, and performance status are the major factors influencing risk of glioma surgrey. Material: Restrospective analysis of all patients who underwent glioma surgery in year 2006. Short-term postoperative complications, 30-days morbidity/mortality, and relation between postoperative morbidity and patients' outcome were studied. Results: Altogether 100 surgeries in 98 patients with glioma tumor were performed. Brain glioma was treated in 97 cases, spinal cord glioma in 3 cases. Histological findings were as follows: pilocytic astrocytoma 2, ganglioglioma 4, plexus papilloma 1, fibrillary astrocytoma 11, anaplastic astrocytoma 4, glioblastoma multiforme 51, gliosarcoma 2, medulloblastoma 2, oligodendroglioma 5, anaplastic oligodendroglioma 10, anaplastic oligoastrocytoma 2, ependymoma 2, and anaplastic ependymoma 1. Spinal cord tumors: fibrillary astrocytoma in cervical level 5–7, ependymoma in thoracic level 8–10, and myxopapillary ependymoma in lumabosacral level. Average preoperative Karnofsky score (KS) was 89, postoperative 87. Complications were observed in 17 cases (epidural hematoma 2, repeated epileptic seizures 2, bleeding into resection cavity 3, postoperative edema causing deterioration of neurological picture 3, peroperative air embolization 1, postoperative fever accompanied by confusion 1, and worsening of neurological picture 5). Preopertive KS in group of patients with complications was 85, postoperative 60. 30-day mortality in group of patients without complications was 0%, in complications group was 35%. By the end of 2007, 4 patients from complication group were alive (mortality 76.4%, postoperative median survival 4.5 months) and 42 patients from noncomplication group were alive (mortality 49.3%, postoperative median survival 9.4 months). Conclusion: Postoperative survival in group patients with any postoperative complication was significantly shorter than in noncomplication group. Risk of surgery even in modern neurosurgical era is still significant (17%). P040. SURGICAL TREATMENT OF INSULAR GLIOMAS M. Oikawa1, T. Ito1, K. Sato1, T. Maruyama2, Y. Muragaki2, H. Iseki2, T. Hori2, H. Nakamura1; 1Nakamura Memorial Hospital, Sapporo, Japan, 2Tokyo Women's Medical University, Tokyo, Japan Surgical resection of tumors located in the insular region is challenging for neurosurgeons. There are four reasons. The first reason is a tumor resection between middle cerebral artery. The second reason is the opercular part is a barrier for resction of tumor. The third reason is the pyramidal tract and the arcuate fasciculus exist around the tumor. The fourth reason is the important small artery (lenticulostriate artery and long insular artery) exists in surroundings of the tumor. Coexisting illness of the insular glioma removal is generated by short odds. We report our experience with 40 intrinsic tumors of the insular between April 2000 and October 2006. The open MRI and navigation were used for checking the residual tumor. Neurological monitoring (SEP, MEP) was used for checking existence of nerve fiber. Awake surgery and cortical mapping were used for checking verbal function. If a correct removal method is used, even if gliomas are located in the insular region, it is possible to remove all safely. P041. PRELIMINARY ANALYSIS FROM AN OBSERVATIONAL STUDY COMBINING MAXIMAL RESECTION AND CONCOMITANT RADIOCHEMOTHERAPY USING TEMOZOLOMIDE IN GLIOBLASTOMA MULTIFORME W. Stummer1, T. Meinel2, M. Sabel1, G. Schackert3; 1Department of Neurosurgery, Düsseldorf, Germany, 2Clinstud GmbH, Hamburg, Germany, 3Department of Neurosurgery, Dresden, Germany Objective: Recently, glioblastoma therapy was advanced by the approval of ALA for enhancing resections and approval of temozolomide for adjuvant radiochemotherapy. It is unknown whether maximal resections combined with concomitant therapy are additive in their effects on outcome. To determine whether additive effects are present, a large observational study was conducted for which preliminary results are available. Methods: Data of 102 of 169 glioblastoma patients recruited into an observational study by the ALA glioma study group were available for this analysis. All patients had early postoperative MRI within 72 hours after surgery and MRIs in 3-monthly intervals. Concomitant therapy was performed according to the EORTC 26981 protocol (75 mg/m2 oral/day during radiotherapy followed by adjuvant temozolomide 5 of 28 days at 150–200 mg/m2). Progression-free survival (PFS) was determined based on contrast-enhancement on gadolinium-enhanced t1 weighted MR images. Patients were directly compared to patients from the phase III ALA study. Results: Patients from the observational study where comparable to patients from the ALA study regarding median age (60.7 vs. 60 years), median KPS (90 vs. 90) and frequency of complete resections (66 vs. 65%). PFS was 8.6 (95% CI: 7.1–10.7) months compared to 5.1 (3.4–6.0) months in the ALA study. Within the observational study, PFS for patients with complete resections was 13.0 (9.9–16.2) compared to 5.1 (3.9–6.3) months for patients with incomplete resections (p=0.000). In the ALA study PFS for complete vs. incomplete resections was 5.9 (3.4–6.8) vs. 3.5 (3.2–5.3) (p=0.0014). Conclusions: These preliminary results indicate that the efficacy of concomitant therapy is enhanced by optimal resections. P042*. CEREBRAL PLASTICITY: NEW ACQUISITIONS GAINED FROM FUNCTIONAL MAPPING OF LESIONS IN ELOQUENT AREAS AND THEIR PROGNOSTIC AND THERAPEUTIC IMPLICATIONS F. Signorelli1, L. De Geronimo2, J. Guyotat3; 1Cattedra ed U.O. Neurochirurgia Università degli Studi di Catanzaro Magna Græcia, Germaneto, Italy, 2Cattedra ed U.O. Neurochirurgia, Universià degli Studi di Catania, Catania, Italy, 3Hôpital Neurologique et Neurochirurgical P. Wertheimer, Lyon, France Background: Tumors infiltrating highly functional structures like sensorimotor and language cortical areas and subcortical pathways cause a reorganization of cortico-subcortical functional maps. Mechanisms of cerebral plasticity take place as a result of surgical removal of lesions and determine a remodeling of neuronal circuitry, which correlates to clinical evolution. Privileged tools for studying mechanisms of cerebral plasticity are functional MRI (fMRI) and cerebral electrical stimulation mapping (ESM). Materials and Methods: We retrospectively analyzed clinical data of 20 patients operated on with the aid of ESM. The preoperative clinical-radiological evaluation included determination of hemispheric dominance for speech function, neuropsychological assessment using Boston Diagnostic Aphasia Evaluation, and fMRI. Patients harboring lesions in or near language areas underwent awake craniotomy for language mapping, while the others displaying lesions involving motor areas were operated on in general anesthesia with the aid of ESM for locating motor pathways. Results: Eight patients harbored a mass lesion in or near language areas and twelve patients had a tumor involving sensorimotor pathways according to clinical presentation and radiological findings. All patients had immediate post-operative deficits. Recovery occurred within 3 months in all of them. Twelve lesions were either totally or subtotally resected on post-operative MRI. Discussion: There are mechanisms of cerebral plasticity taking place before treatment of the lesion and both in an acute stage and at distance from surgical intervention. Even if cortico-subcortical rearrangement of functional circuits seems to be more efficient in case of slow growing lesions, a brain plasticity potential is present also in case of malignant tumors, which may be vulnerable to tumor resection as well as to complementary chemo- and radiotherapy. Understanding how peri-tumoral tissue takes over the lost function and resists to further damage due to tumor relapse and complementary treatments and integrating this knowledge into a wider view of the modifications of cerebral connections in case of brain tumors may guide treatment of cerebral tumors in eloquent areas and define prognosis and rehabilitation programs. P043. USEFULNESS OF LOW-FIELD INTRAOPERATIVE MAGNETIC RESONANCE IMAGING IN BRAIN TUMOR SURGERY J. Chang, D. Kim, S. Kim, K. Lee; Severance Hospital, Seoul, Republic of Korea Objective: Neuronavigation has become a standard technique procedure during brain surgery. However, the imaging used in conventional neuronavigation is acquired preoperatively and thus, cannot project the dynamic changes during surgery and result in significant brain shift and decreased accuracy. Intracranial navigation by using intraoperative magnetic resonance imaging (iMRI) allows the surgeon to reassess anatomical relationships in near-real time during brain tumor surgery. We report our experience with a neuronavigation system coupled to a low-field iMRI system. Materials and Methods: Between September 2005 and August 2007, 148 neurosurgical procedures were performed using the mobile 0.15-tesla PoleStar N-20 iMRI system. The cases included 40 craniotomies and 107 transsphenoidal approaches for 22 gliomas, 105 pituitary adenomas, 5 metastatic tumors, and 15 other tumors. Results: Tumor resection was controlled with the use of image guidance until the final intraoperative images demonstrated that there was no residual tumor or that no critical brain tissue was at risk of compromise. Additional lesion, not otherwise apparent, could be removed and other unnecessary dissection was avoided when the new image confirmed that the surgical goals had been achieved. Additional time incurred with use of the iMRI diminished with increasing experience. There were no iMRI-related complications during surgery. Conclusion: Even though low-field iMRI has certain limitations such as low resolution image or complicated procedures, it has definite advantage rather than conventional surgical technique. iMRI-based neuronavigation offers near-real time brain images and is very helpful, especially in the cases of localization of critical structures in considerable brain shifting situation. Moreover, this system is feasible for tumor resections that require multiple other surgical adjuncts including cortical mapping, monitoring of somatosensory evoked potentials, motor evoked potentials or electrocorticography. Standard neurosurgical drills, microscopes, and other equipment can be used safely in conjunction with this iMRI system. P044*. PLEOMORPHIC XANTHOASTROCYTOMA—LONG-TERM RESULTS OF SURGICAL TREATMENT OF 34 CASES P. Gallo1, P. C. Cecchi2, C. Ghimenton3, N. Schiavo3, G. Pinna4, C. Mazza1, M. Gerosa1, S. Turazzi1; 1Department of Neurosurgery, University Hospital, Verona, Italy, 2Operative Unit of Neurosurgery, Regional General Hospital, Bolzano, Italy, 3Service of Pathology, University Hospital, Verona, Italy, 4Operative Unit of Neurosurgery, Hospital of Baggiovara, Modena, Italy Pleomorphic xanthoastocytoma (PXA) is a rare glial neoplasm involving mainly the supratentorial compartment of children and young adults. Despite many reports, there is little knowledge about long-term results of the treatment of this tumor. Between 1990 and 2006, 34 patients with diagnosis of PXA were operated on at the Department of Neurosurgery of Verona. The mean age at diagnosis was 34 year old (range 12–65). 18 patients were females and 16 males. Symptoms at presentation were seizures (25/34), headache (3/34), and neurological deficits (6/34). Locations of the tumor were: temporal (16/34), frontal (6/34), parietal (6/34), occipital (1/34), paratrigonal region (1/34), hypothalamus (1/34), quadrigeminal plate (2/34), and cerebellum (1/34). Neuroradiological appearance was of solid-cystic lesion in 23 cases, solid lesion in 8 cases, and purely cystic in 3 cases. All patients were treated surgically: in 27 cases the resection was radical, in 6 cases subtotal, and only in 1 case a simple biopsy was performed. In 28 patients diagnosis of grade II PXA was done, and in the remaining six anaplastic features were described. In those latter cases, or when the excision was incomplete, radiation therapy and/or chemotherapy was also accomplished. At a median follow-up of 67.5 months (range 6–216 months) the overall survival was 76%. Complete surgical resection is the treatment of choice for PXA. In cases of an incomplete excision, or for those cases defined as “with anaplastic features”, radiotherapy and/or chemotherapy should be administered. Nevertheless, also for grade II tumors we recommend a very long-term follow-up (>10 years) because the biological behaviour of PXA is relatively unpredictable. P045*. RADIOLOGICAL SURVEILLANCE FOLLOWING SURGERY FOR SUPRATENTORIAL MENINGIOMA: HOW OFTEN AND FOR HOW LONG? A. Hassani, D. Scoones, N. Bradey, P. J. Kane; James Cook University Hospital, Middlesbrough, United Kingdom Background: In the United Kingdom, the National Institute for Clinical Excellence (NICE) has published extensive guidelines for the management of patients with brain tumors. They acknowledge the need for follow up imaging after surgical resection of supratentorial meningiomas but do not advise on imaging protocols. The frequency and duration of post operative imaging could be limited to the time period within which tumor recurrence is likely to occur. Previous studies have concluded that the likelihood of recurrence varies with the histological grade and the extent of resection of the tumor. Design: Retrospective audit of records of all patients that commenced routine follow up imaging after undergoing surgical resection of supratentorial meningiomas between January 1997 and December 2007. Outcome Measures: To assess tumor recurrence and time to recurrence in relation to histological grade (WHO grade 1 or 2) and extent of resection (complete or subtotal). Results: Records of 143 patients (99 females, 44 males) were reviewed. Age range was 20–85 years. 19 tumor recurrences were identified. Recurrence was significantly more likely in patients with WHO grade 2 tumors (p<0.001) and in patients with subtotal resection (p=0.032). Median time to recurrence was 28 months. 17 cases of recurrence occurred within 5 years of surgery. The remaining 2 cases were detected at 62 months and 99 months after surgery. The time to recurrence was significantly shorter with WHO grade 2 meningiomas (p<0.001) and with subtotal resection of the tumor (p=0.003). Conclusion: Almost all cases of recurrence in this cohort were detected on imaging within 5 years of surgery. It therefore seems reasonable to discontinue routine imaging after this time period. The timing of the recurrences in our study would suggest that imaging at 1, 2, 3, and 5 years post-surgery would be adequate. Patients with WHO grade 2 meningiomas or with subtotal resection have an increased risk of recurrence and consequently may require more prolonged imaging follow up at their supervising clinician's discretion. However, as the time to recurrence in these patients is likely to be shorter, there is no reason to suggest that they would benefit from a longer duration of imaging follow up than other patients. P046*. LONG TERM GROWTH PATTERN OF MENINGIOMAS S. Nakasu1, Y. Nakasu2, T. Fukami1, J. Jito1; 1Shiga Unversity of Medical Science, Ohtsu, Japan, 2Shizuoka Cancer Center, Mishima, Japan Introduction: Meningiomas sometimes do not increase their volume further after attaining a significant size. This growth pattern does not correspond to constant linear or exponential growth. We attempted to simulate growth patterns of meningiomas with various growth models. Method: Forty-four patients with meningioma were followed up for 3.1 to 21.7 years (median: 6.8 years) with four or more CT or MR imaging studies. Twenty-five patients including 2 neurofibromatosis cases had 36 asymptomatic tumors. The remaining 19 patients were followed up after surgery with a residual or recurrent tumor. Tumor volume was plotted against time, and relative changes were analyzed with non-linear regression analyses using the Gompertz, logistic, power and exponential curves. Results: Seven asymptomatic tumors showed no growth. In other 48 tumors, non-linear regression analysis revealed that the time-volume curve corresponded to power growth (R2=0.934), exponential growth (R2=0.925), logistic growth (R2=0.964), and Gomperztian growth (R2=0.965). The coefficients of determination (R2) were higher in logistic and Gompertz curves than those of power or exponential growth (P<0.0003). Twenty-eight of 36 asymptomatic tumors had passed the inflection point before or during follow-up and showed deceleration or arrest of growth. Also, 8 of 13 symptomatic grade-1 tumors went over the inflection point post-surgically, while most of them initially showed quasiexponential growth. On the contrary, all 6 atypical meningiomas continued to grow exponentially. Conclusion: The growth of meningiomas correlated highly with the sigmoid curve like Gompertzian or logistic growth. Although benign meningiomas might eventually decelerate their growth, atypical meningiomas were unlikely to pass the inflection point. P047. SURVIVAL AND RECURRENCE OF INTRACRANIAL MENINGIOMAS AFTER SURGICAL TREATMENT H. M. Zimman; Hospital Clinico San Carlos, Madrid, Spain Background: It is well known that intracranial meningiomas can recur in spite of their benign nature and seemingly complete removal. Survival and recurrence is also difficult to assess due to the long period of follow-up that is required. Aim and Methods: To determine the prognostic factors for survival and recurrence after surgical treatment through an ambispective study and identify patients at higher risk of recurrence and death. A total of 208 patients with a mean age of 56.6 years old, and a female to male ratio 3:1 were operated with a minimum follow-up of 60 months. A database was created using patients clinical records with data that included among others: age, gender, location, Karnofsky status, and type of resection. Data was analyzed using a SPSS/PC v.12 (SPSS Inc, Chicago,Ill). Results: The overall survival rate was 90.4% with an estimated survival at 5 and 10 years of 96.1% and 95.6% respectively. Global recurrence was 29.8%. For recurrence, the free recurrence period was 68.3 months. Conclusions: Univariate prognostic factors for increased survival include gender (p=0.03) and complete surgical resection (p<0.001). Univariate prognostic factors for recurrence include gender (p=0.03), grade of resection (p<0.001) and intratumoral hipodensity in imaging (p= 0.002). A multivariate analysis found that resection according to Simpson grades (HR=4.5; CI 95% 2.1–9.5) and intratumoral hipodensity in imaging(HR=2.9; CI 95% 1.3–6.5) are independent factors that correlate to a higher risk of recurrence. P048. DIAGNOSIS AND TREATMENT OF INVASIVE SKULL BASE MENINGIOMAS A. Bekyashev, V. Cherekaev, A. Korshunov, I. Pronin, A. Golanov; Burdenko Neurosurgical Institute, Moscow, Russian Federation Introduction: Invasive skull base meningiomas are challenging from the surgical point of view. Although benign, meningiomas of the skull base are locally invasive and have a high recurrence rate. Materials and Methods: A total of 136 patients (82 females and 54 males) with intra- and extracranial meningiomas aged 11–72 years (median age = 49 years) were operated on by different variants of bifrontal and orbito-zygomatic approaches between 1998 and 2005. Tumor locations include anterior cranial fossa with or without extension to cribriform plate, ethmoid sinus, sphenoid sinus, orbit, subtemporal fossa, and nasal cavity. Most patients had benign meningiomas. Skull base reconstruction was usually performed with a pericranial flap, and/or abdominal fat. A temporal muscle flap was also used in some patients. The clinical outcomes were graded as follows: good (complete recovery), moderate (improvement), and poor (unchanged or severely disabled). Results: Total tumor resections were achieved in 67 cases, subtotal or large resections in 56 cases, and partial resection in 13 cases. Of 136 treated patients, good and moderate outcomes were observed in 81 and 44 patients, respectively, while 11 patients had poor outcome and 2 patients died postoperatively from pulmonary embolism within 10–15 days after surgery. Postoperative complications included CSF leakage (8 cases), infection (4 cases), transient impaired vision (9 cases), oculomotor deficit (18 cases), anosmia (12 cases). Conclusions: Total tumor removal at an early stage is the recommended therapy for the most patients but is not always feasible because of vital structures involvement at the skull base. Extensive tumor resections with intraoperative damage of cranial nerves lead to significant neurology deficiency, thus the optimal treatment of invasive skull base meningiomas is subtotal resection with subsequent radiotherapy. P049*. PARASAGITTAL LOCATION AS A BAD PROGNOSTIC FACTOR IN TERMS OF RECURRENCE AND TUMORAL CONTROL FOR MENINGIOMAS J. Villard, A. Pica, J. Bloch; Centre hospitalier universitaire vaudois, Lausanne, Switzerland Purpose: Meningiomas are the second most common primary tumors of the brain after gliomas. Many therapies are currently used ranging from surgery to radiotherapy including stereotactic radiosurgery and stereotactic fractionated radiotherapy. The goal of the present study was to analyze our series of patients with meningiomas of any location except skull base, treated by either single or combined therapies and see whether implantation was a prognostic factor for tumoral control. Patients and Methods: Retrospective observational study in a single center. Between January 1983 and December 2007, a total of 161 meningiomas were treated at our center. All consecutive patients with a meningioma, excluding skull base meningiomas, were enrolled in this study. 42 women and 34 men were treated and median age at diagnosis was 61.48 years. Of the 76 meningiomas treated, 55 underwent single treatment and 21 combined treatments. Tumor volumes ranged from 0.2 to 113.1 cm3 (median 13.2). We compared the group of parasagittal meningiomas (28/76) to the other non skull base meningiomas. Results: Median follow-up was 30 months (range 9.4 to 288.6) including surgical records, MRI imaging, discharge letters, and histological records. Parasagittal meningiomas had a median volume of 13.4 cm3. 53.57% had only surgery and 46.43% had combined treatments. Their grade was WHO grade 1 in 69.23%, grade 2 in 26.92%, and grade 3 in 3.85%. When surgical resection was performed 47.62% were Simpson 1, 28.81% Simpson 2, and 28.57% Simpson 4. There was no significant difference in sex, age, size, grade, type of treatment, and Simpson between parasagittal and other locations. Nevertheless tumoral control was lower for parasagittal meningiomas (62.96%) and time to recurrence was significantly lower as well: 61.9 months vs. 159.8 months (p = 0.022). Discussion and Conclusion: Our data have shown that although parasagittal meningiomas have the same epidemiologic, morphologic, histologic distribution, and treatment modality than meningiomas with other locations, their behavior is different. Parasagittal location was identified as a statistically significant prognosis factor for higher recurrence rate and lower tumoral control. P050. PREOPERATIVE ANALYSIS OF THE RADIOLOGICAL FACTORS ASSOCIATED WITH TUMOR-BRAIN ADHESION IN INTRACRANIAL MENINGIOMA W. Joo, Y. Hong; Catholic University of Korea, Seoul, Republic of Korea Background: The purpose of this study is to evaluate the preoperative radiologic factors associated with tumor-brain adhesion in intracranial meningioma. In particular, we focused on usefulness of MRI and DSA in predicting tumor-brain adhesion during surgery. Methods: The subjects were 79 patients with intracranial meningioma who underwent tumor excision at which time neurosurgeons examined the tumor-brain adhesion. The authors evaluated age, sex, the preoperative MRI finding including tumor volume, peritumoral rim, shape of tumor, signal intensity of tumor obtained T2WI, presence of peritumoral edema, and presence of pial blood supply in DSA. Results: Of the various factors, male sex (p=0.012), the presence of peritumoral edema (p=0.001), shape of tumor (p<0.001), tumor volume (p=0.000), and pial blood supply (p=0.000) were significantly correlated with tumor-brain adhesion. Age (p=0.153), the signal intensity of tumor parenchyma in T2WI (p=0.161), and peritumoral rim (p=0.170) were not statistically significant with the tumor-brain adhesion. Conclusion: We retrospectively examined the findings of MRI and DSA performed before meningioma removal and clarified the relationship between the findings and tumor-adhesion. Male, larger tumor, irregular margin, peritumoral edema, and pial blood supply should be considered high-risk group of meningioma removal, especially in eloquent area. P051. MENINGIOMA SURGERY IN THE ELDERLY. THE INFLUENCE OF CONCOMITANT DISEASES AND POST-OPERATIVE COMPLICATIONS ON THE OUTCOME OF PATIENTS M. Caroli1, A. Cardia2, C. Menghetti1, S. Borsa1, A. De Santis2, M. Fornari2, S. Gaini1; 1Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Fondazione IRCCS, Milano, Italy, 2Istituto Ortopedico Galeazzi IRCCS, Milano, Italy In a previous report we developed a grading system called Clinical-Radiological Grading System (CRGS), in order to standardize surgical indications in elderly patients (older than 70) affected by intracranial meningiomas. On the basis of the results we have demonstrated that patients with a score lower than 10 had a bad prognosis regardless of surgical treatment, those with a score between 10 and 12 had a prognosis positively influenced by surgery, and those with a score higher than 12 had a good prognosis regardless of surgical treatment. In the present study we analyzed, during 6 years (2000–2006), a series of 108 surgical patients older than 70 affected by intracranial meningioma in which the selection for surgery was made by the means of the CRGS as a predictor of outcome. The series is composed of 58 women and 50 men ranging from 70 to 86 (mean age 75). The lesion location was the following: convexity (20), falx (13), parasagittal (48), olfactory groove (3), presellar region (1), tuberculum sellae (1), sphenoid ridge (2), middle fossa (3), tentorial edge (6), cerebellar (3), ponto-cerebellar corner (6), and intraventricular (2). In three cases multiple meningiomas were demonstrated. Hystological examination revealed atypic meningioma in 15 cases. Neurological symptoms were the following: seizures (13), motor disturbances (19), cognitive and language problems (18), gait and balance disturbances (17), cranial nerves deficits (6), and visual impairment (6). Two patients were asymptomatic and the diagnosis was made by the presence of cranial hyperostosis. The associated diseases were the following: arterial hypertension (16), cardiac diseases (13), lung diseases (2), diabetes (5), thrombocytopenia (2), hypothiroidism (2), glaucoma (2), vascular diseases (3), and kidney disease (1). The mortality rate within 3 months after surgery was 7% and the 1-year mortality ratio was 15%. Post-operative complications and the presence of the above mentioned concomitant diseases influenced the duration of the hospitalization: the median length was 19.5 days (range from 5 to 41 days). Post-operative complications occurred in 19 cases: broncopneumonia (2), pulmonary embolism (5), worsening of neurological deficit (7), status epilepticus (2), partial seizures (2), diabetes decompensation (1), chronic subdural hematoma after 1 month (1), and acute subdural hematoma requiring evacuation (1). Eighteen patients were transferred in a rehabilitation unit. The presence of post-operative complications and the length of post-operative rehabilitation influenced the quality of life of the patients in term of self sufficiency (Karnofsky performance status) and cognitive status (Mini Mental State Examination) at follow-up examination. P052. MRI AND DSA PARAMETERS AS PREDICTIVE FACTORS OF POSTOPERATIVE NEUROLOGICAL DEFICIT IN POTENTIALLY RADICALLY RESECTABLE MENINGIOMAS P. Kozler1, V. Benes1, D. Netuka1, F. Kramar1, F. Charvat2; 1Department of Neurosurgery, Prague, Czech Republic, 2Department of Radiology, Prague, Czech Republic Background: The present study is aimed at finding radiological parameters that can provide indirect information on invasive growth of meningioma relevant enough to predict the likely risk of postoperative neurological deficit development. Materials and Methods: The cohort is made up of 40 consecutive adult patients (from January 2004 till May 2005) of comparable general condition parameters (age 18–75 years, KRS 70–100, ASA 1–2) with meningiomas solely attacking brain tissue with the whole of their volume. The Pearson chi-square test was used for statistical evaluation. Results: Radical resection of the meningioma was attained in 33 (82.5%) patients, subtotal resection in seven (17.5%). Ten (25%) patients at 7 days after the operation had their neurological findings worse than before. Seven were found to have a new neurological deficit and there were three cases of progression of the existing neurological symptoms. Three patients (7.5%) were worse off neurologically than before the operation as long as 3 months after surgery while seven had their neurological condition restored ad integrum. All of the ten patients with postoperatively worsened neurological findings had their meningiomas localized in the eloquent area. A correlation was found between the eloquent area and neurological deficit, and also between the presence of peritumoral edema (small, medium, large) and neurological deficit. Interdependence was detected between a discernible tumor-brain interface and absence of edema, between a discernible tumor-brain interface and dural type of vascular supply, and between the dural type of vascularization and absence of edema. Conclusions: As follows from the outcome, meningioma growth in the eloquent area and the presence of peritumoral edema are the two adverse parameters predicting the development of postoperative neurological deficits. In contrast, dural types of vascularization, visible tumor-brain interface, meningioma growing in a non-eloquent area, and the absence of peritumoral edema are favorable predictive parameters. To go by the results, in the presence of the last two parameters the patient need not be exposed to the risks of invasive selective angiography. P053. 11C METHIONINE PET IN TARGET VOLUME DEFINITION OF STEREOTACTIC RADIOTHERAPY AND RADIOSURGERY OF INTRACRANIAL MENINGIOMA M. A. A. M. Heesters1, J. Pruim2, G. Wester1, H. P. Bijl1, R. A. Bolt1, J. M. C. van Dijk3, J. J. Mooij3, J. A. Langendijk1; 1Dept Radioth University Medical Center, Groningen, Netherlands, 2Dept Nuclear Medicine University Medical Center, Groningen, Netherlands, 3Dept Neurosurgery University Medical Center, Groningen, Netherlands Objective: In meningioma WHO grade I, long term tumor control with minimal side effects is achievable with stereotactic radiotherapy (SRT) and radiosurgery (SRS). However, precise target volume (GTV) definition is critical due to the possible infiltration into venous sinus, bone, and along cranial nerves or vessels and dura. Meningiomas show a high 11C methionine uptake and can be visualized by PET (MET-PET). In this study we tested the hypothesis that the addition of MET-PET would result in a smaller GTV and to a radiotherapy dose reduction on critical brain structures. Materials and Methods: 20 patients were studied with pre SRT/SRS CT, GAD enhanced T1 3D MRI and MET-PET (ECAT HR+). GTV was defined by MR/CT only, MET-PET only, and by the combination (final GTV). MET-PET GTV was defined based on the window at the tumor to brain interface. GTV calculated from CT/MR only, MET-PET only and final GTV were compared using paired samples statistics. Discrepancies in GTV areas were analyzed. In 5 patients with skull base meningioma, SIMRT or SRS was performed using MR/CT GTV and final GTV. Mean dose reduction on hippocampus, chiasm, and brain stem was calculated. Patients were treated with NOVALIS and BRAIN LAB Iplan/Brainscan. Results: Meningiomas were visualized in 18 patients, in 2 patients MET-PET was negative possibly due to small tumor volume. MET-PET defined GTV were significantly smaller compared to CT/MR based GTV, mean 8.7 cm3 (range 0.83–27.9) and 15.9 cm3 (range 2.5–61.6) (p=0.02). The addition of MET-PET did not led us to significantly reduce the final GTV compared to CT/MR (mean 12.1 cm3 range (1.75–36.2) (p=0.06). MET-PET adequately identified the main tumor mass but not CT/MR suspected small extensions at the tumor margin below the PET camera resolution (5–6 mm) (along dural tails (89% of cases), blood vessels (11%), and cranial nerves (39%). In several cases larger extensions with diameter > 5 mm suspected on MR/CT were negative on MET-PET. Here MET-PET showed no infiltration of cavernous sinus (35% of cases), sagittal sinus (22%), and skull base (17%). In 5 patients with absent cavernous sinus infiltration on MET-PET the final GTV was reduced compared to the MR/CT GTV and a radiotherapy dose reduction on hippocampus (mean dose 31% (MR/CT plan) vs. 23% (MR/CT/PET plan), brain stem (24% vs. 18%), and chiasm (82% vs. 72%) was demonstrated. Conclusions: MET-PET GTV are smaller compared to MR/CT GTV although we did not significantly reduce final GTV. In patients with suspected cavernous sinus infiltration on MR/CT the addition of MET-PET reduced final GTV with a dose reduction on critical brain structures. P054. ASSESSMENT OF MENINGIOMA INVASIVENESS USING AN IN VITRO ASSAY J. F. Megyesi, E. Dyer, W. McDonald, D. Macdonald, R. Hammond, P. Costello; University of Western Ontario, London, ON, Canada Background: Brain tumor progression is partly dependent on the cells' ability to invade and grow into surrounding brain. Development of an assay to assess both tumor invasion as a measure of aggressive behavior and the inhibition of that invasion through application of chemotherapeutics could provide clinically valuable data regarding an individual patient's response to treatment. Methods: Using an established ex vivo invasion assay, tissue samples from 14 surgical patients radiographically diagnosed with meningioma were assessed. The actual invasion distance (μm) of tumor cells were monitored using video-microscopy over 5 days and WHO grades pathologically confirmed. Results: Video-microscopic surveillance revealed that 13/14 samples demonstrated no cellular invasion. Neuropathological diagnosis revealed eleven WHO grade 1 meningiomas (benign), one WHO grade 2 meningioma, and one hemangiopericytoma. The single WHO grade 3 meningioma demonstrated significant tumor invasion and inhibition by cisplatin. Conclusions: These laboratory observations suggest a correlation between the histopathology (WHO grade) of a meningioma and its invasiveness (a characteristic of malignant behavior). This invasion assay may be used to assess tumor invasion and possibly response to chemotherapeutics to help individualize adjuvant treatment regimens. P055. NIMUSTINE (ACNU) PLUS TENIPOSIDE (VM26) IN RECURRENT GLIOBLASTOMA M. Glas1, T. Hundsberger2, M. Stuplich1, D. Wiewrodt3, D. Kurzwelly1, B. Nguyen-Huu4, K. Rasch1, U. Herrlinger1; 1Clinical Neurooncology Unit, University of Bonn, Bonn, Germany, 2Dept. of Neurology, Kantonspital St. Gallen, St. Gallen, Switzerland, 3Dept. of Neurosurgery, University of Mainz, Mainz, Germany, 4Dept. of Neurology, University of Mainz, Mainz, Germany Background: There is no established standard chemotherapy for recurrent glioblastoma (GBM). In a previous trial (NOA-01), the combination of nimustine and teniposide showed efficacy in previously untreated GBM. After temozolomide has been established as the standard for primary therapy of GBM, nimustin (ACNU) and teniposide (VM-26) are now in use as salvage chemotherapy for recurrent GBM. However, there are no data on toxicity and efficacy of this regimen in recurrent GBM Patients and Methods: In two neurooncological centers, all patients with recurrent glioblastoma who had received nimustine (90 mg/m2, day 1/42) and tenoposide (45–60 mg/m2, days 1–3/42) chemotherapy were analyzed retrospectively for progression-free survival, overall survival, and toxicity. Results: Thirty-five patients (median age 51 years, range 25–71 years), most of them pretreated with temozolomide were identified. The rate of progression-free patients at 6 months after initiation of therapy was 29%. The median overall survival after initiation of nimustine/teniposide was 6 months and 23% of patients survived 1 year or longer after initiation of nimustine/teniposide. Grade 4 hematotoxicity was observed in 12 of 35 patients (34%) and in 14 of 83 evaluable chemotherapy courses (17%). No high-grade non-hematological toxicity was observed. Conclusions: These data support the efficacy of nimustine and teniposide combination chemotherapy in recurrent GBM. Nimustine and teniposide combination therapy is associated with a comparably high rate of high-grade hematotoxicity. P056*. COMBINATION OF BEVACIZUMAB AND IRINOTECAN FOR RECURRENT MALIGNANT GLIOMAS: A RETROSPECTIVE STUDY OF EFFICACY AND SAFETY M. Martinez Garcia1, G. Reynes2, C. Balaña3, C. Fernandez Chacon4, M. Benavides5, P. Perez Segura6, A. Herrero7, A. Garcia Velasco8, X. Perez Martin1, M. Gil Gil1; 1Instituto Catalan de Oncologia (H. Duran y Reynals), L'Hospitalet, Spain, 2H. La Fe, Valencia, Spain, 3Instituto Catalan de Oncologia (H. German Trias i Pujol), Badalona, Spain, 4M D M Anderson, Madrid, Spain, 5H. Carlos Haya, Malaga, Spain, 6H. Clinico San Carlos, Madrid, Spain, 7H. Miguel Servet, Zaragoza, Spain, 8Instituto Catalan de Oncologia (H. Trueta), Girona, Spain Background: Despite new strategies the prognosis of recurrent malignant gliomas (MG) is dismal. MG are characterized by vascular proliferation, with overexpression of proangiogenic factors and receptors such as VEGF-A and VRGFR-2. Some prior studies have explored the potential role of combined treatment with irinotecan and bevacizumab. The aim of this study is to confirm efficacy and safety of this combination in non-selected consecutive patients (pts). Methods: Data from 7 Spanish centers were collected retrospectively. All pts were >18 years, had to sign an informed consent and to present: histological documented MG; progression after radiation and temozolomide; measurable disease on MRI; have received at least 3 infusions of treatment schedule (irinotecan 125 mg/m2 and bevacizumab 10 mg/kg every 2 weeks) for a maximum of a year. Response rate (RR) was determined by MRI (performed every 6 infusions) using MacDonald criteria. Kaplan-Meier and multivariate analysis (MA) (Cox model) were performed to determine progression free survival (survival until progression or death) (PFS) and overall survival (OS). Results: From July 2006 to December 2007, 54 pts (35 glioblastoma, 15 anaplastic astrocitoma, 4 anaplastic oligoastrocitoma, and 1 anaplastic oligodendroglioma) were treated with this schedule. Median age: 52.3 years (25–74). Median number of prior chemotherapy: 2 (1–4). Six cases had received irinotecan previously. 33 pts (62%) with KPS⩾80% and 33 pts (63%) had neurological symptoms. 33 pts received dexamethasone with median dosage: 34 mg (1–18). 22 were taking a non enzyme-inducing antiepileptic drug. The median cycles of the schedule: 9 (4–23). Toxicity grade 3–4: Asthenia in 6 pts; thrombocytopenia 1; neutropenia 1; mucositis 2; thomboembolic complications (TEC) 3; skin 1; hemorrhage out of CNS 2; and severe cognitive impairment 4. Efficacy: 31 pts had response (4 complete response); 12 pts stable disease ⩾3 months and 9 progression as best response. RR was 59.6% (95% CI [45.1–73]). Mean follow-up: 5.8 months (1.9–17.9). Mean PFS was 7.4 months (6–8.6). OS was 16.17 months (8.3–24). In the univariate analysis for response no statistical difference was seen for gender, KPS, age, and dexamethasone. KPS <80% (HR 6.1 [1.3–28.2]) was significant for OS, but there was no signification for dexamethasone (HR 2.96 [0.8–10.7]). KPS<80% (HR 4.4 [1.4–13.4]) was significant for PFS, but not dexamethasone (HR 2.2 [0.9–5.3]). In the MA, only KPS was significant for OS and for PFS. Conclusion: Combination of bevacizumab and irinotecan in recurrent MG improves RR, EFS, and OS when compared with previously reported data. However, this regimen is not free of severe toxicity (TEC and severe cognitive impairment) and requires a careful selection of patients. P057. PROSPECTIVE EVALUATION OF IRINOTECAN AND BEVACIZUMAB IN RECURRENT MALIGNANT GLIOMA: NOTICEABLE RESULTS OF RESPONSE IN A POOR PROGNOSTIC GROUP J. Pichler1, J. Buchroithner2, S. Nöbauer3, G. Wurm2, W. Wies2, S. Wimmer4, J. Trenkler4, J. Fischer2; 1Landesnervenklinik, Department of Internal Medicine and Neurooncology, Linz, Austria, 2Division of Neurosurgery, Linz, Austria, 3Department of Internal Medicine and Neurooncology, Linz, Austria, 4Department of Neuroradiology, Linz, Austria Purpose: After first published data on this treatment regimen, we conducted a prospective evaluation of this kind of chemotherapy in relapsed glioma patients. No validated standard treatment is available to substantially improve outcome. Patients and Methods: 14 adult patients with recurrent glioma were included. 12 GBM, 1 gliomatosis cerebri, and 1 brain stem glioma. 10/14 had 2 or more relapses. Mean age at first diagnosis was 43 years (range 18–72). 13 patients underwent surgery (4 total, 6 subtotal, 3 biopsies). The patients with gliomatosis and brainstem glioma had no radiation therapy. All others were treated with standard radiotherapy (60 Gy) and concomitant temozolomide, followed by various cycles of adjuvant temozolomide until 6 cycles or less, if relapse occurred. After progression second line chemotherapy contained other chemotherapy regimen. Treatment with irinotecan 125 mg/m2 and Avastin 10 mg/kg were administered every two weeks. Dose reduction was necessary in 5 patients due to toxicity; only non–enzyme inducing antiepileptic drugs were allowed; oral anticoagulants were prohibited. Response evaluation by MRI using MacDonald's criteria and rCBV measure was performed. Results: Radiographic responses were noted at first evaluation after 6 weeks in 12 of the 14 patients (86%); 1 patient with gliomatosis remains stable, and 1 GBM patient progressed. At this time 3 patients progressed after 3 months; all others did not reach PFS yet. Toxicity was mild with no grade 4 hematoxicity, moderate, and rare gastrointestinal symptoms. Conclusions: This combination chemotherapy has exciting response rates with acceptable toxicity. We can confirm earlier studies on this treatment. PFS rate at 6 months and TTP will be presented at the meeting. P058. EPITHELIAL GROWTH FACTOR RECEPTOR INHIBITORS FOR TREATMENT OF RECURRENT OR PROGRESSIVE HIGH-GRADE GLIOMA M. Preusser1, E. Gelpi2, A. Rottenfusser3, K. Dieckmann3, G. Widhalm4, W. Dietrich4, A. Bertalanffy4, D. Prayer5, J. Hainfellner2, C. Marosi1; 1Department of Internal Medicine 1, Vienna, Austria, 2Institute of Neurology, Vienna, Austria, 3Department of Radiotherapy and Radiobiology, Vienna, Austria, 4Department of Neurosurgery, Vienna, Austria, 5Department of Neuroradiology, Vienna, Austria Introduction: Erlotinib and Gefitinib (EGFRinhib) are tyrosine kinase inhibitors specifically targeting epidermal growth factor receptor (EGFR). We present data of an exploratory study analyzing EGFRinhib monotherapy in patients with recurrent/progressive malignant glioma. Patients: 21 patients with recurrent/progressive malignant glioma were included in our study. EGFRinhib administration was started at a median of 1.8 years (range 0.54 to 10.95) after primary surgery. 20/21 patients had undergone radiotherapy and all patients had received at least one (range 1 to 5, median 2) line of previous systemic anti-neoplastic therapy. Patients orally received a daily dose of 100 mg or 150 mg Erlotinib or 250 mg Gefitinib. Results: Median age at initial diagnosis was 47.9 years (range 31.9 to 76 years). 18 patients received a total of 92.8 months (median 3.03) of Erlotinib treatment and 3 patients received a total of 16.1 months (median 6.06) of Gefitinib treatment. The best responses were partial remission in one patient under Erlotinib treatment and in two patients under Gefitinib treatment, respectively. Median time to progression was 3.05 months. Six months after start of EGFRinhib treatment, 4/21 (19%) patients had not experienced tumor progression and 6/21 (29%) patients were alive. Expression of EGFRwt, EGFRvIII, PTEN, or EGFRvIII/PTEN co-expression in tumor cells did not significantly correlate with time to tumor progression or survival time. EGFRinhib administration had to be discontinued due to toxicity (grade 3 rash) in only one patient. Conclusion: EGFRinhib monotherapy is associated with therapeutic efficacy in only a small percentage of malignant glioma patients. Reliable biomarkers predicting tumor response to EGFRi need to be identified. J Neurooncol. 2008. P059. NIMOTUZUMAB WITH CHEMOTHERAPY IN RECURRENT MALIGNANT GLIOMA: ANALYSIS OF A CASE SERIES A. D. Muggeri, B. D. Diez; Institute of Neurological Research Dr Raul Carrea (FLENI), Buenos Aires, Argentina Recurrent malignant glioma has a dismal prognosis and therapeutic options are scarce. Nimotuzumab (N) is a humanized mAb against the EGFR extracellular ligand binding domain with high affinity and specificity. After previous potentially encouraging reports on N in this setting, N with chemotherapy was applied to patients with recurrent malignant glioma in an institutional series. In a retrospective analysis, 10 patients with recurrent high-grade glioma and measurable disease (WHO III, n = 4; WHO IV, n = 6) all with EGFR amplification were treated with N (200 mg weekly × 6 as induction and twice a month for 6 months afterward) in combination with temozolomide in 3 patients (2 patients 200 mg/m2/day for 5 each 28 days and one 75 mg/m2 for 15 days out of 30) or lomustine (110 mg/m2 doses each 40 days) in 7 patients. The MacDonald criteria were employed for response assessment. The response was documented by MRI in week 8 and assessed afterward every 12 weeks. All the toxic events were seen with the combination of lomustine + N. One episode of grade 2 diarrhea and one event of seizure at the moment of the infusion were seen. Grade 3 hematological toxicity was observed in 4 of 7 and grade 2 in 1 of 7. One patient was hospitalized for febrile neutropenia. Three of 10 patients progressed at 4, 8, and 10 weeks; 2 had some evidence of improvement in neuroimaging but less than the 25% limit to assess them as partial responders (one progressed at week 19, and the other are still in response at week +10), and 5 had stable disease (2 progressed at week 12 and 30 and 3 continued in stable disease for +10, +10, and +23 weeks). Six of 7 patients who received the combination with lomustine had moderate to severe hematological toxicity. The potential of this approach should be further refined and explored. P060. IMATINIB PLUS HYDROXYUREA IN PRETREATED NON-PROGRESSIVE GLIOBLASTOMA (GBM)—A SINGLE CENTER PHASE II STUDY G. Dresemann1, C. Hosius2, Z. Nikolova3, E. Schleyer4; 1CTC-Standort Franz-Hospital, Dülmen, Germany, 2Novartis Pharma Oncology, Nürnberg, Germany, 3Novartis Pharma Oncology, Basel, Switzerland, 4Klinikum Merseburg, Merseburg, Germany Background: GBM is a highly malignant tumor with a median survival of less than 15 months. Dysregulated signaling of platelet derived growth factor receptors (PDGF-Rs) is implicated in pathogenesis. Imatinib (I) plus Hydroxyurea (HU) is effective in patients (pts) with recurrent progressing GBM. In a pilot group of 30 pts with recurrent GBM the progression free survival at 6 and 24 months was 32% and 16% respectively. 37% of pts achieved disease stabilisation (SD). Despite the aggressive course of GBM, short periods of SD after primary treatment or effective treatment of relapse is common. The current Phase II study was designed to analyze the efficacy of I plus HU treatment in GBM pts with SD as sequential maintenance treatment. Methods: From Dec. 2003 up to June 2005 30 pts were included. No enzyme-inducing anticonvulsive drugs were allowed. I at the dose of 600 mg and 1000 mg of HU were given as a continuous daily treatment, follow up included blood cell count weekly and magnetic resonance imaging (MRI) every 6 weeks. The primary endpoint is 12 months progression free survival (PFS). Results: All pts are eligible for safety, for 6, 12, 24, and 36 months PFS and 6, 12, 24, and 36 months overall survival (OS); 25 pts were male, 5 pts female, and the median age was 44 years (32 to 71). 6 pts had primary GBM 24 pts scondary GBM following lower grade malignancy. All 30 pts had prior irradiation, 21 pts had temozolomid containing, and 9 pts nontemozolomid containing regimens. 8 pts were free from relapse, 17 pts after first, and 5 pts after second relapse. 25 pts had measurable disease in MRI scan, and 5 pts had no evidence of disease. The median follow up was 40 months. The best response was partial remission in 4 pts. SD for more than 3 months in 20 pts. 6, 12, 24, and 36 month PFS was 60% (18/30), 40% (12/30), 17% (5/30), and 17% (5/30). 6, 12, 24, and 36 month OS was 90% (27/30), 67% (20/30), 37% (11/30), and 17% (5/30). 3 of 5 pts with PFS of more than 3 years had secondary GBM (3/6). Hematotoxicity grade 2 and 3 occurred in 11 out of 30 pts (anemia grade 3: 2 pts; anemia grade 2: 4 pts; leukopenia grade 3: 2 pts; grade 2: 7 pts; thrombopenia grade 2: 4 pts) and required dose reduction of HU in 8 pts, dose reduction of I in 1 patient and G-CSF subcutaneously in 8 pts. Conclusions: I (600 mg/d) and HU (1,000 mg/d) showed efficacy as maintenance treatment in pts with GBM in stage of SD with low toxicity profile. Data suggest that efficacy might be higher in pts with secondary GBM. Confirmation is necessary. P061*. RECHALLENGE WITH TEMOZOLOMIDE IN RECURRENT GLIOMAS A. Wick1, C. Pascher2, W. Wick1, M. Weller3, U. Bogdahn2, P. Hau2; 1Neurooncology, University of Heidelberg, Heidelberg, Germany, 2Neurology, University of Regensburg, Regensburg, Germany, 3Neurology, Universitätsspital Zürich, Zürich, Switzerland Objectives: Temozolomide (TMZ) is the standard of care for patients with newly diagnosed glioblastoma (GBM) as well as recurrent anaplastic glioma (AG) and GBM. Recent data suggest enhanced efficacy of alternative schedules of TMZ at recurrence. Few data have been published on the efficacy of TMZ after the failure of TMZ using conventional dosing regimens. Methods: A retrospective review of patients with recurrent glioma rechallenged with TMZ was conducted. Results: A total of 90 rechallenges were identified in 81 patients, 14 with low-grade glioma (LGG), 22 with AG, and 45 with GBM. Median age was 46 years with median Karnofsky Performance Score of 90 at rechallenge. Partial (PR) or complete responses (CR) to TMZ were observed in 32.0% of AG and 11.1% of GBM. Six-month progression-free survival (PFS) was 41.2% in LGG, 48% in AG, and 31.9% in GBM. Relevant toxicity (NCI-CTC grade 3 to 5) was observed in 32 of 90 rechallenges. Discontinuation of rechallenge TMZ was due to toxicity in 6 patients and due to progressive disease (PD) in 60 patients. Conclusions: TMZ was well tolerated and generated a high response rate in patients who had previously failed TMZ. These data suggest that rechallenge with TMZ in patients who previously demonstrated disease stabilization with TMZ treatment and also patients who progressed on TMZ should be further investigated in a randomized study. P062. SAFETY AND EFFICACY OF CHEMOTHERAPY WITH BCNU IN THE TREATMENT OF RECURRENT GLIOMA C. Dictus1, D. Chatziaslanidou1, N. Becker2, P. Lichter2, C. Herold-Mende1, C. R. Wirtz1, A. Unterberg1, R. Ahmadi1; 1Department of Neurosurgery, University Hospital, Heidelberg, Germany, 2Department of Molecular Genetics, German Cancer Research Center, Heidelberg, Germany Introduction: Despite advances in different therapy modalities, the treatment of recurrent glioma remains challenging. Chemotherapy is a therapeutic option and BCNU (carmustine) is one of the drugs used in this context. However, its preference to other nitrosoureas remains controversial due to a possible development of pulmonary fibrosis. Besides, little is known about its effectiveness in case of recurrence. Therefore we sought to determine safety and efficacy of BCNU treatment in recurrent glioma. Material and Methods: From 1995 until 2005, data of patients with recurrent glioma were retrospectively evaluated in view of possible side effects of BCNU treatment that were classified according to the NCI Common Toxicity Criteria (CTC) version 2.0. For outcome analysis, data of patients with recurrent GBM receiving either BCNU or no adjuvant therapy (control) were analyzed for known prognostic factors, overall survival (OS), and survival from relapse (SV). Univariate analysis was done by Kaplan-Meier estimates and multivariate analysis by a modified Cox regression model. Results: 163 patients with recurrent glioma received a median total dose of 1662 mg BCNU during a median number of 5 cycles. Indications for BCNU treatment were mainly recurrent glioblastoma WHO IV (n=84) and anaplastic glioma WHO III (n=57). Few patients received BCNU for recurrent low-grade glioma WHO II (n=22). 88 patients (54%) experienced drug-related side effects which were usually of mild nature (CTC I/II; 45% of all patients). Severe side effects CTC III/IV were rarely observed (9% of all patients). Only one patient (0.6%) experienced a clinically relevant pulmonary fibrosis CTC IV requiring mechanical ventilation. Outcome analysis of 134 patients with recurrent GBM revealed beneficial effects of adjuvant BCNU therapy. Both OS (17 vs. 12 months) and SV (10 vs. 4.5 months) were significantly prolonged compared to controls. In a multivariate analysis, BCNU treatment was shown to be an independent prognostic factor for prolonged survival. Conclusion: In our patient sample, BCNU turned out to be a well tolerated cytostatic substance with mostly mild side effects. Contrary to the literature, the most dreaded side effect, a clinically relevant pulmonary fibrosis, was detected in one out of 163 patients only. In case of recurrent GBM, BCNU treatment proved to be an independent prognostic factor for prolonged survival. Therefore, in recurrent glioma the use of BCNU might be preferred over more aggressive chemotherapy regimens in terms of safety and patient outcome. P063. PHASE II STUDY OF IFOSFAMIDE, CARBOPLATIN, AND ETOPOSIDE IN RECURRENT GLIOBLASTOMA T. Aoki1, K. Nojima1, T. Mizutani1, A. Takasu2; 1Kitano Hospital, Brain tumor Center, Department of Neurosurgery, Osaka, Japan, 2Kitano Hospital, Brain Tumor Center, Department of Pathology, Osaka, Japan Purpose: To evaluate the efficacy and tolerability of ifosfamide, carboplatin, and etoposide (ICE) in patients with recurrent glioblastoma. Patients and Methods: This was an open-label, single-center phase II trial. Forty-two patients with progressive glioblastoma after surgery, standard radiotherapy, and a first-line temozolomide-based or ACNU-based chemotherapy, were enrolled. The primary endpoint was progression-free survival at 6 months (PFS-6), and secondary endpoints were response rate, toxicity, and survival. Chemotherapy consisted of Ifosfamide (700 mg/m2 on days 1, 2, and 3), carbopaltin (100 mg/m2 on day 1), etoposide (70 mg/m2 on days 1, 2, and 3), every 6 weeks. PFS-6 was 37%. The median PFS was 17 weeks. Response rate was 27%. Adverse events were generally mild (grade 1 or 2) and consisted mainly of alopecia. Conclusion: This regimen is well tolerated and has activity in patients with progressive glioblastoma. P064. CYBER KNIFE RETREATMENT IN PATIENTS WITH HIGH-GRADE GLIOMA I. Milanesi1, M. De Santis1, A. Bergantin2, M. Fumagalli1, L. Bianchi2, A. Silvani1, L. Fariselli1; 1Isituto Neurologico C. Besta, Milan, Italy, 2Centro Diagnostico Italiano, Milan, Italy Purpose: We evaluated retrospectively the efficacy and toxicity of sterotactic radiotherapy or radiosurgery retreatment in recurrent gliomas. Materials and Methods: Between April 2005 and September 2007, 57 patients (58 lesions) with high-grade glioma, 26 (45%) WHO grade III (AA) and 32 (55%) grade IV (GBM), were treated with stereotactic radiotherapy. Minimum follow-up was 6 months. Forty patients underwent chemotherapy with temozolomide (75–150 mg/m2) or with cisplatin (100 mg/m2) and carmustine (100 mg/m2) for 5 cycles. Conformal radiotherapy after surgery or biopsy was made in all patients with a median dose of 60 Gy (2 Gy/fract). Median time between conventional and stereotactic radiotherapy was 10 months. Thirty-one lesions were treated with single fraction, while 27 with hypofractinated schedule. Median treated volume was 5.3 cc (range 0.6–33.9). Median dose was 14 Gy in radiosurgery and 20 Gy in 3 fraction in streotactic treatment; median isodose was 78%. Results: Median survival time after stereotactic retreatment was 16.95 months (CI 95%: 11.1–22.8 months). Twenty-one lesions have a progression disease (63.6%). Median time to progression was 10.25 months (CI 95%: 5.6–14.9 months). Toxicity: We observed 2 acute toxicities, consistent in vasogenic edema 2 months after the treatment, controlled by high doses of steroids. Late toxicity affected 2 patients: In the first case after 15 months of follow up an MRI image consistent in pseudotumoral radionecrosis was observed and subsequently confirmed by spectroscopy, PET, and Histology. A second case of a radionecrosis MRI image 11 months after SRS was evaluated as a recurrent tumor in PET imaging. Conclusion: Stereotactic radiotherapy with Cyber Knife could be a therapeutic option in recurrent and multifocal high-grade gliomas.The non-invasive fixation of the skull used in Cyber Knife System allows the choose of fractionated schedules. P065. CAN BORON NEUTRON CAPTURE THERAPY PROLONG THE SURVIVAL OF RECURRENT MALIGNANT GLIOMA PATIENTS? S. Miyatake1, S. Kawabata1, N. Nonoguchi1, K. Iida1, S. Miyata1, K. Yokoyama1, T. Kuroiwa1, H. Michiue2, M. Kirihata3, K. Ono4; 1Osaka Medical College, Takatuski, Japan, 2Okayama University, Okayama, Japan, 3Osaka Prefectural University, Sakai, Japan, 4Kyoto University Research Reactor Institute, Kumatori, Japan Objective: We have applied a form of tumor selective particle radiation known as boron neutron capture therapy (BNCT) to malignant brain tumors. We report the survival benefit of BNCT for newly diagnosed glioblastoma patients with special reference to the results of RTOG recursive partitioning analysis (RPA) classes (submitted for publication). As there has been no standard treatment for recurrent gliomas so far, it has been difficult to evaluate the survival benefit of BNCT for recurrent malignant gliomas. Here we introduce the survival benefit of BNCT for recurrent malignant glioma patients, with special reference to new RPA classification based on phase 1 and 2 trials planned for recurrent malignant gliomas advocated by New Approaches to Brain Tumor Therapy CNS Consortium (NABTT) in J Clinical Oncology (25:2601–2606, 2007). Methods: Since 2002, we have treated 22 cases of recurrent malignant gliomas with BNCT. All cases had been treated by standard treatment including radiotherapy and chemotherapy mainly by X-ray treatments and temozolomide or nimustin prior to BNCT. After BNCT, radiographical improvement and aggravation were followed by MRI and biological activity was followed by 18F-boronophenylalanine (BPA)-PET. Cause of death was estimated by these modalities. Also, overall survival was evaluated with special reference to RPA advocated by NABTT as above. Results: All cases showed radiographical improvement at once. The median survival time (MST) of BNCT-treated recurrent gliomas was 11 months, while that of total NABTT cases (N=333) was 7 months, where 2 studies have the similar distribution of the patients as to RPA. MST of NABTT RPA classes were 25.7, 17.2, 3.8, 10.4, 5.6, 6.4, and 4.9 months for class 1 to 7, respectively. The MST of BNCT-treated cases were 43, 22, 11, 8, 7, 22, and 11, for class 1 to 7, respectively. In each RPA class, BNCT showed good survival benefit for recurrent gliomas patients, although case numbers were limited. Especially BNCT could prolong the poorest RPA class from 4.9 months (NABTT) to 11 months as MST. Three cases were lost due to uncontrollable radiation necrosis, 10 were lost due to CSF dissemination, 5 were lost by local recurrence, and 2 were lost by other cause of death. Two patients are still alive at the time of analysis. Conclusions: BNCT could prolong the survival of patients with recurrent gliomas not only for the good prognosis group but also for the poor prognosis group. The major cause of death was CSF dissemination after BNCT. P066. MR DIFFUSION-WEIGHTED IMAGING IN THE DELINEATION OF TREATMENT VOLUME OF HIGH-GRADE GLIOMA: PRELIMINARY RESULTS OF A PROSPECTIVE TRIAL D. Beldì1, L. Masini1, G. Loi2, A. Stecco3, A. Littera3, A. Carriero3, M. Krengli1; 1Radiotherapy, University of Piemonte Orientale, NOVARA, Italy, 2Medical Physics, Hospital Maggiore della Carità, NOVARA, Italy, 3Radiology, University of Piemonte Orientale, NOVARA, Italy Purpose: The present study analyzed the role of MR diffusion-weighted (DW) imaging in the detection of treatment volumes for radiotherapy. Literature data show that MR DW images may be able to detect tumor infiltration into peritumoral edema and into normal-appearing white matter (WM) allowing a better delineation of clinical target volume (CTV). Materials and Methods: Twelve patients affected by high-grade gliomas (WHO III-IV) operated and candidate to adiuvant chemo-radiotherapy have been enrolled thus far. Prior to radiotherapy, they underwent MRI study by MR DW imaging. The apparent diffusion coefficient (ADC) and the fractional anisotropy (FA) were analyzed. ADCs and FA were measured on volumes of interest generated from isotropic DW images represented by the enhancing tumor, hyperintense regions adjacent to enhancing tumor, and the normal-appearing WM adjacent to hyperintense regions. The same measurements were performed on symmetric locations in the contralateral hemisphere. Results: Mean ADCs values in enhancing tumor and in peritumoral hyperintense regions were increased compared with contralateral normal WM (828.16 mm2/sec vs. 588.33 mm2/sec, and 984.3 vs. 545.5 mm2/sec). No difference was seen in mean ADCs between peritumoral normal-appearing WM and the corrisponding contralateral normal-appearing WM (547.5 vs. 575.5 mm2/sec). No difference was appreciable in mean FA values between glioma regions and normal tissues. Mean FA values in peritumoral hyperintense regions were slightly decreased compared to contralateral WM (0.267 vs. 0.395). Conclusions: Our data confirm the possible role of ADC in the detection of tumor infiltration in perilesional edema to be included in the CTV. ADC values do not give information on tumor infiltration into normal-appearing white matter (WM), but the limited number of observations does not allow to draw definitive conclusions. The role of FA value deserves further investigation. P067. THE PROGNOSTIC VALUE OF RADIOLOGICAL BIO-MARKERS FOR DETECTION OF CEREBRAL GLIOMA GRADES AND EARLY EVALUATION OF TUMOR RESPONSE TO RADIATION THERAPY USING MRI PERFUSION AND SPECTROSCOPY M. M. Abdel Wahab, K. M. Maher, M. A. Osman; Faculty of Medicine, Ain Shams Univ, Heliopolis Cairo, Egypt Background and Purpose: The early and accurate prediction of treatment response in brain gliomas after radiation therapy using MRI perfusion and spectroscopy may provide an opportunity to switch to more beneficial to nonresponders instead of the limited delayed structural data obtained via the use of conventional MRI. Our aim was to analyze these recent modalities to evaluate the combined application on the treatment plan. Methods: Forty-six patients with brain astrocytomas were recruited in this study, they were examined prospectively before and after radiation therapy at regular intervals over a period of two years, using conventional MRI, MRI perfusion, and spectroscopy. The findings correlated the histopathological grade of the tumor and different tumor response to treatment for each individual patient. For those patients with early poor response or resistant to radiation, chemotherapy was added in the form of temozolamide 175 mg/m2 for 5 days every consecutive 28 days; meanwhile for patients with good response, no further treatment was added with regular follow-up. Results: Initial base line radiological studies before radiotherapy were correlated with the histopathological grade. Both MRI spectroscopy and biomarkers choline/creatinine, choline/NAA were statistically significant (0.001, 0.004) respectively to differentiate between high grade (III, IV) and low grade (II), as well as MRI perfusion (P= 0.042); meanwhile, conventional MRI data were not statistically significant except for necrosis and edema (P=0.002). For the assessment of the early response after 4 weeks of completion of radiotherapy, conventional MRI was only significant for the enhancement (P=0.0001) Biomarkers of spectroscopy were highly significant for choline/creatinine, NAA/creatinine and choline/NAA, with P values 0.005, 0.025, 0.01, respectively. MRI perfusion was also statistically significant with P value 0.004. Conclusion: Both MRI perfusion and spectroscopy are important and promising new modalities for diagnosis and early therapeutic evaluation of brain tumor response after radiation therapy for proper selection of patients in need of further chemotherapeutic treatment. P068. MRI AND FET-PET DEMONSTRATE EARLY RESPONSE TO BEVACIZUMAB AND IRINOTECAN THERAPY IN RECURRENT MALIGNANT GLIOMA J. Schroeteler1, M. Rapp1, A. Ringelstein2, G. Stoffels3, K. Langen3, W. Stummer1, H. Steiger1, C. Ewelt1, M. Sabel1; 1Department of Neurosurgery, Duesseldorf, Germany, 2Department of Radiology, Duesseldorf, Germany, 3Department of Neuroscience, Jülich, Germany Purpose: Due to the primary treatment of patients with glioblastoma multiforme (GBM) with alkylating drugs (AD) the role of a rechallenge with AD upon recurrence is subject to discussion. A new treatment option with bevacizumab, an antibody against VEGF, and irinotecan, a topoisomerase I inhibitor is currently under investigation. In contrast to an excellent radiographic response rate of 63% in the treatment of recurrent GBM as demonstrated by MRI, clinical progression and survival parameter did not match the radiological response. Since VEGF has been implicated in alteration of the blood-brain barrier (BBB) the radiological response might merely be due to this effect on BBB. We therefore evaluated the response of the regiment on recurrent GBM by early MRI and metabolic investigation by Fluroethyltyrosin (FET)-PET. Patients and Methods: At present, 9 patients with recurrent GBM after treatment with radiotherapy and concomitant plus adjuvant temozolomide (TMZ, median 7 cycles) were included in our observation study (median observation time as yet 10 weeks) and treated with 125 mg/m2 irinotecan and 10 mg/kg bevacizumab in a six week cycle. MRI and FET-PET studies were performed prior to initiation, 3 weeks after the first and one month after the third therapy. 2 patients had FET-PET scans 3 days after the first therapy. Results: All 9 patients showed a decreased contrast agent enhancement on MRI scan after the first 2 therapies. 7 patients showed a homogeneous reduction of contrast enhancement (CE) by a median of 52%. 2 patients demonstrated a heterogeneous reduction of CE. Accordingly, FET-PET scans demonstrated a reduction of metabolic activity in all patients, with a focal high activity in those 2 patients with heterogeneous reduction of CE. FET-PET scans performed as early as 3 days after the first therapy demonstrated in both cases a homogenous and nearly complete reduction of FET activity. Both patients with heterogeneous reduction of CE and with a focal high activity of FET demonstrated multifocal recurrence 1 month after therapy. Conclusion: The combination of bevacizumab and irinotecan seems to induce an impressive alteration of the CE and metabolic activity of recurrent GBM. Though a final conclusion can not be drawn as yet due to the short observation time, a heterogeneous reduction of CE and metabolic activity might be correlated with early progression. The observation that the reduction of FET activity was observed as early as 3 days after initial treatment indicates a direct effect of this treatment on the BBB. Further observation of the clinical outcome will further illuminate the effectiveness of this therapeutic approach. P069*. RELATIVE VALUE OF MAGNETIC RESONANCE SPECTROSCOPY, MAGNETIC RESONANCE PERFUSION, AND 2-(18F)FLUORO-2-DEOXY-D-GLUCOSE POSITRON EMISSION TOMOGRAPHY FOR DETECTION OF RECURRENCE OR GRADE INCREASE IN GLIOMAS I. Galeano1, R. Prat1, A. Lucas2, J. Martínez2, M. Martín3, R. Conde1, R. Amador4, L. Bataller5, G. Reynes3; 1Hospital Universitario La Fe. Dept. of Neurosurgery, Valencia, Spain, 2Hospital Universitario La Fe. Dept. of Radiology, Valencia, Spain, 3Hospital Universitario La Fe. Dept. of Medical Oncology, Valencia, Spain, 4Hospital Universitario La Fe. Dept. of Radiation Oncology, Valencia, Spain, 5Hospital Universitario La Fe. Dept. of Neurology, Valencia, Spain Introduction and Objectives: In high-grade gliomas, assessment of response by MRI is often difficult because of the frequent persistence of residual, enhanced lesions. Other tools are needed to distinguish viable tumor from radionecrosis, and to identify new high-grade glioma (HGG) foci in a previously diagnosed low-grade glioma. Materials and Methods: In a consecutive series of patients (pts) with glioma, different techniques, including MR spectroscopy (MRS), 2-(18F) fluoro-2-deoxy-D-glucose positron emission tomography (GPET), and dynamic contrast enhanced perfusion MRI (MRP), were performed to assess the presence of viable HGG inside uncertain T1 enhanced lesions. Results: 24 pts were included (14 men, 10 women). In 2 pts, 2 suspected recurrences were assessed, resulting in 26 episodes. Tumor location was lobar in 18 pts, deep in 5 pts, multicentric in 1 pt. Initial surgery was only biopsy in 4 cases and resection in 22 cases, with remaining tumor in 21. Histologic diagnosis were obtained in 13 pts: glioblastoma (5), anaplastic astrocytoma (3), anaplastic oligodendroglioma (2), anaplastic ependimoma (2) grade II oligodendroglioma (1). After surgery, 23 pts were given radiotherapy and 19 pts received chemotherapy. Findings in previous MRI were new enhanced lesions in 8 cases and increased enhancement of previous lesions in 18 cases. The reason for carrying out new assessment techniques were to differentiate between radionecrosis and recurrence/remaining tumor in 21 cases, and to confirm a suspected grade increase in 5 cases. MRS was performed in 24 cases, showing a pattern of HGG in 12, radionecrosis in 11, and low-grade glioma in 1 case. GPET showed a hypermetabolic lesion in 8 cases and hypometabolic areas 18 cases. MRP demonstrated increased perfusion in 8 cases and no increase in 10 cases. Discrepancy among different techniques was observed in 8 cases. The positive predictive value (PPV) and the negative predictive value of every technique were as follows. MRI: PPV=58.3%. MRS: PPV=92.3%, NPV=90%. GPET: PPV=75%, NPV=50%. PRM: PPV=100%. NPV=100%. To differentiate viable tumor from radionecrosis, RMS and PMR reached a PPV and a NPV of 100%, whereas for GPET, PPV and NPV were 66.6% and 60%, respectively. Conclusions: To distinguish between viable HGG and radionecrosis, gadolinium-enhanced MRI gives a high false-positive rate, while MRS and PMR are superior to GPET to discriminate among tumor recurrence, grade increase, and radionecrosis. P070. 18F-FET PET IN EARLY DETECTION OF RELAPSE/PROGRESSION IN HIGH-GRADE GLIOMAS F. Bertolini1, B. Bagni2, A. Valentini3, R. Depenni1, M. Cobelli4, A. Casolo2, A. Fontana1, A. Falasca3, P. Giacobazzi5, G. Pinna3; 1Medical Oncology, University Hospital, University of Modena and Reggio Emilia, Modena, Italy, 2Nuclear Medicine, University Hospital, University of Modena and Reggio Emilia, Modena, Italy, 3Neurosurgery, Nuovo Ospedale Civile S. Agostino-Estense, Modena, Italy, 4Neuroradiology, University Hospital, University of Modena and Reggio Emilia, Modena, Italy, 5Radiotherapy, University Hospital, University of Modena and Reggio Emilia, Modena, Italy Background: The purpose of this report was to investigate the potential role of positrone emission tomography using 18F-fluoroetyltyrosine (FET-PET) in early detection of disease relapse or progression in high-grade gliomas. Methods: FET-PET (Advance, General Electric Medical System, Milwaukee, WI) was performed in 7 patients (pts) with high-grade gliomas after a neuroradiological suspicious of relapse/progression. Ninety minutes after the intravenous injection of approximately 185 MBq of FET, late images of the brain were obtained. FET uptake in the lesion was semiquantitatively evaluated by measuring the maximal standardized uptake value (SUVmax) and compared with the results of MRI/spectroscopy or histological specimen after surgery. Results: In the last year (November 2006–2007) 7 pts (6 men and 1 woman; median age, 47; range: 21–69) followed at our institution underwent FET-PET after the evidence of lesion enhancement on MRI. Three had a diagnosis of glioblastoma multiforme (all radically operated) and four anaplastic astrocytoma/oligoastrocytoma (2 partial and 2 complete exeresis). Four pts received radiotherapy (60 Gy in 30 fractions) and concomitant temozolomide (75 mg/msq/daily) and three only radiotherapy. Median time from the end of post-surgical therapy and neuroradiological doubt of relapse/progression was 6.3 months. In 5 pts FET-PET demonstrated an increase of FET uptake (median SUVmax values=2.9; range: 1.7–3.4) in enhancing lesions on MRI. One patient presented a doubtful uptake in the site of the lesion, while another one presented a “circle pattern” uptake in the site of surgery. Spectroscopy was performed in 5 of 7 pts: in 4 cases it was suggestive of relapse/progression and in 1 case of radionecrosis. One patient underwent surgery for relapse: the histological sample demonstrated an active glioblastoma (KI67=15%). After a median follow-up of 26.1 months, 5 patients died for disease progression and 2 patients are still alive with no clear evidence of disease relapse/progression. Concordance between FET-PET and MRI/spectroscopy or histological specimen was showed in 6 of 7 patients (85%). Conclusions: FET-PET can be useful in the management of high-grade gliomas to detect relapse or tumor progression early after post-surgical treatment (chemo and/or radiotherapy). A longer follow-up and more cases are necessary to confirm this observation. P071. IMAGE-BASED RADIATION THERAPY PLANNING FOR BRAIN TUMORS WITH F-18-FLUOROETHYLTYROSINE (FET) PET AND MRI: POTENTIAL IMPACT ON TARGET VOLUME DELINEATION A. Pica1, J. O. Prior2, P. Maeder3, M. Paschoud4, R. Stupp5, R. Mirimanoff1, A. Bischof Delaloye2, G. Allenbach2; 1Radiation Oncology, Lausanne, Switzerland, 2Nuclear Medicine, Lausanne, Switzerland, 3Radiology, Lausanne, Switzerland, 4Radiophysics, Lausanne, Switzerland, 5Oncology, Lausanne, Switzerland Aim: PET imaging with amino acids has the potential to image glioma invasion better than MRI, which commonly may show nonspecific T2-signal extension beyond the borders of T1-signal enhancement. Our aim is to define the potential impact of FET PET on target volume delineation as compared to MRI. Materials and Methods: We retrospectively evaluated 10 patients affected by high-grade gliomas. They underwent both MRI and FET PET as part of their intial work up. An experienced radiation oncologist delineated T1 and T2 signal target volumes based on MRI images. FET PET target volume was defined using a SUV threshold = 1.6, contralateral SUV averaged over a 1 cm diameter region. Fusion of PET and T1/T2 signal MRI images was performed using the PMOD software and the common volume between PET and T1, between PET and T2 (intersection volumes) were computed. Results: Mean tumor volumes on T1-/T2-signal MRI and PET were 34±31, 21±25 and 128±84 mL, respectively. In one patient, a 1.4 threshold had to be used because of low tumor uptake. There was no significant difference in volumes derived from PET or T1-signal MRI (p=0.14). PET volumes were were significantly smaller (p=0.001) than when derived from the T2-signal MRI and represented only 13% of the T2-signal volumes. Conclusions: Our analysis suggests that FET PET would have an impact on delineating radiation therapy target volumes in most patients and may help in radiation therapy planning. Outcome studies are needed to determine the effect of such PET image-based radiation therapy planning on progression-free and overall survival. P072. THE ROLE OF 99MTC-TETROFOSMIN SPECT IN THE ASSESMENT OF BRAIN TUMORS G. A. Alexiou, S. Tsiouris, A. Goussia, A. P. Kyritsis, K. S. Polyzoidis, S. Voulgaris, A. D. Fotopoulos; University Hospital of Ioannina, Ioannina, Greece Purpose: The noninvasive functional characterization of an intracranial lesion represents a major goal, substantially enhancing the neuromorphological information obtained by conventional radiology. We set out to evaluate the contribution of technetium-99m Tetrofosmin (99mTc-TF) SPECT in the evaluation of brain tumors. Material and Methods: Eighty patients (37 male, 43 female, mean age 57.8 years) were prospectively enrolled in the study. The diagnosis was meningioma (27), glioblastoma (18), anaplastic astrocytoma (4), anaplastic oligodendroglioma (3), low grade astrocytoma (4), low grade oligondroglioma (1), radiation necrosis (4), intracerebral hematoma (10), hemangioblastoma (1), colloid cyst (1), swannoma (1), pituitary adenoma (1), and metastasis (5). All patients underwent SPECT imaging and within a week surgical excision was performed. From the surgical excision specimens Ki-67 antigen was assessed with the MIB-1 immunostaining method. Results: The tumor tracer uptake intensity on visual qualitative image assessment ranged from profound to very faint (in a low-grade fibrillary astrocytoma). 99mTc-TF brain SPECT managed to differentiate tumor recurrence from radiation necrosis and neoplastic from non-neoplastic intra cerebral hemorrhage. Furthermore, there a was a linear clear positive correlation between the 99mTc-TF uptake and Ki-67 antigen in gliomas and in meningiomas. Conclusion: Imaging by 99mTc-Tetrofosmin provides useful information on the lesion's functional nature and could be implemented in the diagnostic workup. P073*. THALLIUM SPECT IMAGING OF SUPRATENTORIAL PRIMARY BRAIN TUMORS: HOW USEFUL IS IT IN ROUTINE CLINICAL PRACTICE? A. D. Kane, N. Brady, M. Richardson, D. Scoones, I. R. Chambers, P. J. Kane; James Cook University Hospital, Middlesbrough, United Kingdom Background: 201Tl-SPECT imaging is used in the assessment of supratentorial primary brain tumors (SPBT): increased uptake of isotope reflects malignant change. Commonly scans are reported using a qualitative inspection technique and described as “no increased uptake” or “increased uptake” indicating low grade and high grade tumor respectively. Previous studies have attempted to relate 201Tl uptake in SPBT to histological grade using quantitative examination of images. Aims: Audit the use of 201Tl-SPECT in the management of SPBT and assess the benefit of routine quantitative analysis. Methods: 201SPECT scanning was performed routinely in patients with CT/MR proven SPBT. Scans were performed on a dual-headed gamma camera (Siemens E-Cam) using low energy collimation. Tomographic axial slices, oriented to brain anatomy, were analyzed. Qualitative analysis was performed by an experienced neuroradiologist and a report of “no increased uptake” or “increased uptake” relative to the rest of the cerebral cortex was reported for the tumor site. For quantitative analysis a region of interest (ROI) was drawn on the axial section at the tumor site for scintillation counting. An equivalent “mirror” ROI was also defined in the contralateral hemisphere in the same section and the skull vault. The ratio of scintillation counts in the tumor site to those of the contralateral hemisphere was calculated (T/C) and also tumor to contralateral skull ratio (T/S). Sensitivity, specificity, positive, and negative predictive values were calculated using histology. ROC analysis was performed using histology and T/C and T/S as separate test variables. Results: Data from 76 patients were audited. With qualitative examination of the 201Tl SPECT scan the test values for scans reported as “increased uptake” being high grade and “no increased uptake” being low grade tumors was: sensitivity 80.0%, specificity 85.4%, positive predictive value 82.4%, and negative predictive value 83.3%. ROC curve analysis of quantitative studies did not indicate significant improvement in predictive yield (area under the curve for T/C and T/S ratio versus histological grade were 0.881 and 0.917 respectively). Conclusion: 201Tl-SPECT imaging has high sensitivity and specificity in the diagnosis of high grade SPBT. In clinical practice quantitative analysis does not confer any benefit over qualitative analysis provided by an experienced neuroradiologist. P074. EVALUATION OF MULTIPLE TUMOR PARAMETERS TO IMPROVE THE NON-INVASIVE CLASSIFICATION OF PRIMARY BRAIN TUMORS WITH 11C-METHIONINE PET D. J. Coope1,2, C. Eggers3, S. Vollmar3, W. Heiss3, K. Herholz1; 1The University of Manchester Wolfson Molecular Imaging Centre, Manchester, United Kingdom, 2Department of Neurosurgery, Salford Royal NHS Foundation Trust, Salford, United Kingdom, 3Max-Planck-Institute for Neurological Research, Cologne, Germany Background: Gliomas demonstrate significant heterogeneity both in terms of outcome and imaging characteristics within histological grades and particularly between histopathological and genetic sub-types. Methionine uptake as measured with positron emission tomography (PET) has been shown to correlate with histological grade, but interpretation of the results is difficult unless the histological sub-type is known. We hypothesized that imaging biomarkers of other features known to reflect malignancy including tumor volume, shape, and heterogeneity could be measured from methionine PET data to support this interpretation. Method: Methionine PET scans performed in 39 individuals from 2003–4 were identified from the database at the Max-Planck-Institute for Neurological Research in Cologne. Scans were analyzed using the ratio to a normal uptake map as previously described. A software application was developed in R to enable standardized, highly reproducible image analysis. Tumor “masks” were defined using a 3D region-growing technique constrained by voxel connectivity. Several statistical measures were recorded for this tumor mask including the volume, characteristics of the border, and variability of the methionine uptake including texture measures. Receiver operating characteristic (ROC) analysis was performed for each of these parameters to evaluate accuracy in the discrimination of (1) grade II vs. III/IV and (2) grade III vs. IV tumors. Results: Ten factors were selected including peak methionine uptake, the volume of the tumor mask, measures relating to irregularity of the tumor border/shape, heterogeneity within the tumor volume, and the distribution of uptake values within adjacent brain. Each of these features produced significant results on ROC analysis (p=0.000 to 0.010) with the volume of the region of increased methionine uptake being most effective in separating low and high-grade gliomas. Threshold values were defined from the ROC curves to identify results with high specificity for low-grade tumors. 10 of the 13 (77%) grade II tumors analyzed exhibited 3 or more of these characteristics as compared to 2 of the 26 (8%) grade III/IV tumors. A score derived from these features demonstrated a greater area under the ROC curve (AUC=0.88) than any of the individual measures in isolation. Conclusion: PET with amino-acid tracers enables multiple tumor measures to be derived from a single diagnostic investigation. Combined evaluation of multiple parameters in an individual tumor may be used to improve accuracy in the non-invasive characterisation of primary brain tumors. P075*. USEFULNESS OF F-DOPA PET IN THE DIFFERENTIATION OF RECURRENT GLIOMA FROM RADIATION NECROSIS F. Payer1, W. Wurm2, S. Weiss3, B. Zechner2, F. Fazekas2; 1Neurooncology, Neuroradiology, Graz, Austria, 2Neurology, Graz, Austria, 3Neurooncology, Graz, Austria Objectives: Differentiation of tumor recurrence/progression from necrosis after radiation and chemotherapy remains a challenging problem. Conventional imaging by MRI is not always reliable, because it can not always differentiate tumor progression from necrosis. The aim of the study was to evaluate the potential of F-DOPA PET in this setting. Methods: Twenty-five patients with recurrent brain gliomas or radio-/chemonecrosis, suspected on the basis of MRI, were studied with F-DOPA PET. For semi-quantitative analysis the portion of the tumor with the highest F-DOPA accumulation was selected and tumor to contralateral normal cortex ratios (T/N) were determined by region-of-interest analysis. Results were correlated with histopathological findings or, in cases without surgery or biopsy, with subsequent clinical course and MRI findings. Results: Histological examinations showed viable tumor in 11 and necrosis in 4 cases. Seven other cases were considered to have tumor and 3 to have necrosis based on neurological symptoms and findings on follow-up MRI. Using the mean T/N a statistical significant difference (p=0.004) was found between recurrence of high-grade glioma (n=17; mean 2.4, 95% CI 2.0–2.8) and necrosis (n=7; mean 1.5, 95% CI 1.2–1.8). There was no significant difference between high-grade glioma and low-grade glioma (n=3; mean 1.9, 95% CI 1.4–2.3) or between low-grade glioma and necrosis. Conclusion: F-DOPA PET demonstrated excellent visualization of high-grade and low-grade glioma. Our preliminary data suggest that F-DOPA PET seems to be a complementary imaging tool in differentiating tumor recurrence/progression from necrosis in contrast enhancing lesions on MRI in patients with high-grade glioma. P076. 2-18F-FLUOROMETHYL-L-PHENYLALANINE PET IN THE ASSESSMENT OF GLIOMA PROGRESSION: PRELIMINARY RESULTS C. Chaskis, H. Everaert, T. Stadnik, M. Dujardin, B. Neyns; UZ Brussel, Brussels, Belgium Gadolinium-enhanced MR imaging (Gd-MRI), together with the evaluation of the neurological condition of the patient, makes part of the clinical assessment in glioma. Interpretation of contrast-enhancement remains however challenging. In case of clinical worsening without corroborating changes on Gd-MRI, functional imaging could play a role in the assessment of progression. Several amino acids accumulate intensively in malignant cells, as a result of an overexpression of L-type amino acid transport system. The low uptake of these compounds in normal brain makes them valid alternatives for FDG in brain gliomas. We evaluated 2-18F-Fluoromethyl-L-Phenylalanine (FMP), a radio-labeled amino acid, for positron emission tomography (PET) imaging in a prospective series of 23 treated glioma patients (13 males and 10 females, average age 48.6 y [range 25–77]); WHO differentiation grade was I in 1 patient, grade II in 7 patients, grade III in 5 patients, and grade IV in 10 patients. Clinical worsening was observed in 20 patients, consisting on new focal signs, cognitive deterioration and/or increased seizures. Stable clinical condition was noted in 3 patients. Gd-MRI was evaluated as disease-free in 2 patients, progression-free in 8, and progressive disease in 15, respectively. Dynamic PET studies were acquired after injection of 156 ± 57 MBq FMP. Both dynamic and summed data were reconstructed using iterative algorithms, and corrections for attenuation and scatters were applied. Volumes of interest over the tumor and normal brain tissue were manually placed. Accumulation of FMP in non-affected brain tissue was low, rendering high target-to-background ratios. Intense FMP accumulation at the tumor site was observed in 20 patients, limited focal uptake in 1 patient, and absence of tracer accumulation in 2 patients. Patients with clinical worsening showed intense FMP uptake, except one who presented also disease-free MRI. Second line therapy was considered, except in this latter case, consisting on radiotherapy or chemotherapy in 6 patients and study treatment in 12; 1 patient refused treatment. During a 4 months follow-up period, rapid tumor progression was observed in 10 of them; 4 patients improved and 4 remained stable. In patients without clinical deterioration, intense FMP uptake was noted in 1 case, and slight focal or no uptake in 2 cases. These 3 patients, together with the patient mentioned above, were followed up conservatively, neither showing further clinical worsening nor MRI progression. FMP-PET offered useful information in the assessment of recurrent glioma, significantly correlating with the evolution of the patients (Pearson chi-square 0.011). We therefore believe that FMP-PET could be used in patients showing clinical progression but non-corroborating MRI findings. A further evaluation in a large series is planned. P077. SIMULTANEOUS INTEGRATED BOOST TECHNIQUE BY HELICAL TOMOTHERAPY FOR THE TREATMENT OF GLIOBLASTOMA MULTIFORME WITH 11C-METHIONINE PET K. Miwa1, S. Takenaka1, J. Shinoda1, M. Matsuo2, T. Ueda3, K. Yokoyama3, J. Yamada3, H. Yano4, T. Iwama4; 1Chubu Medical Center for Prolonged Traumatic Brain Dysfunction, Minokamo, Gifu, Japan, 2Department of Radio-oncology, Kizawa Memorial Hospital, Minokamo, Gifu, Japan, 3Department of Neurosurgery, Kizawa Memorial Hospital, Minokamo, Gifu, Japan, 4Department of Neurosurgery, Gifu University School of Medicine, Gifu, Japan Objective: Helical tomotherapy system (HT), a new intensity-modulation method, combines an intensity-modulated fan beam with the helical motion of the gantry relative to the patient. The higher specificity and sensitivity of 11C-methionine positron emission tomography (MET-PET) in brain tumors has been demonstrated in previous studies and may be useful for delineation of tumor volume. We developed a technique that incorporates routine integration of MET-PET in hypo-fractionated high-dose irradiation using simultaneous integrated boost technique (SIB) by HT. In the cases described below, we examined the combined use of MET-PET and MRI to quantify the effect of MET-PET in defining tumor volume and in monitoring the tumor's response to radiation for SIB by HT. Methods: We performed SIB by HT to 15 patients of GBM with gross total or subtotal resection. The gross tumor volume (GTV)-1 was defined as the area of intensive MET uptake, including the surgical resection surface. GTV-2 was defined as the area of moderate MET uptake around the resection cavity. The planning target volume (PTV)-1 encompassed GTV-1 plus a 5 mm margin, and PTV-2 encompassed GTV-2 plus a 2 mm margin. SIB by HT was performed in 8 fractions, planning the dose for GTV-1 at 68 Gy (biologically effective dose: BED = 126 Gy), PTV-1 at 56 Gy (BED = 95 Gy), and PTV-2 at 40 Gy (BED = 60 Gy). Concomitant chemotherapy consisting of temozolomide was given to all patients. For the follow-up study, MET-PET was carried out 3 months following SIB in 10 of 15 patients. Results: Our target planning demonstrated that the conformity index was 95% and the homogeneity index was 107%. No severe acute toxicity was observed in all patients. All patients were able to complete their treatment. In acute phase, radiation necrosis didn't develop in the area of PTVs. In 9 of 10 patients, the uptake value on MET-PET was considerably decreased or unchanged 3 months following SIB. In just one patient, the uptake value on MET-PET was increased 3 months following SIB. In this patient, local tumor recurrence within 6 months had been demonstrated after all. In our series, actuarial local tumor control rates at 6 months and 1 year were 88% and 67%, respectively. Actuarial overall survival rate at 1 year was 77%. Conclusions: Our series demonstrate that SIB with HT planning using MET-PET offers excellent target coverage and uniformity, and that MET-PET has great efficacy for monitoring treatment response after SIB. Our regimen of SIB contributed to the control the regional tumors, resulting in better survival of patients. P078. 2-18F-FLUORO-L-TYROSINE PET/CT IMAGING BEFORE AND AFTER RADIOTHERAPY OF MENINGIOMAS I. M. Rutten1, B. G. Baumert2, N. Withofs1, R. Hustinx1; 1C.H.U de Liège, Liège, Belgium, 2University Hospital Maastricht, Maastricht, The Netherlands Purpose: We have previously shown that 18F-TYR PET imaging accurately delineates irradiated skull base meningiomas with tumor-to-cortex activity ratios ∼2.5. The aim of the present study was to evaluate whether 18F-TYR PET may be a good indicator of the response of meningiomas to radiotherapy (RT), which is difficult to evaluate using only MRI. Patients and Methods: We here report preliminary results on 4 patients who underwent one PET/CT before RT and another one on the mean 16 months (range 14–23 months) after RT. F-TYR PET/CT studies were acquired 15 minutes after IV injection of 300 MBq F-TYR, using a Gemini Dual system. The metabolic activity was assessed by calculating the tumor to cortex activity ratios. Results: In 3 patients, the uptake ratio decreased by 25 to 45%. In 1 patient, this parameter slightly increased. The volumes of high uptake remained stable. The patient whose ratio increased received the lowest dose (50 Gy versus 54, 58 and 60 Gy for the others). MRI images showed stable volumes for the three first patients and a reduction for the last one. Conclusion: Although preliminary, these results suggest that 18F-TYR PET may give indications about post-RT evolution of meningiomas. A longer follow-up and a larger population of treated patients are needed to fully assess the predictive value of this technique. Its ability to be an early predictor of the response to treatment is an intriguing possibility. P079. RADIOSURGERY PLANNING OF INTRACRANIAL PARASAGITTAL MENINGIOMA USING 3D-VOLUME MRI, MR VENOGRAPHY, DTI AND 11C-METHIONINE PET M. A. A. M. Heesters1, J. M. C. van Dijk2, J. Pruim3, H. P. Bijl1, R. A. Bolt1, R. J. M. Groen2, J. A. Langendijk1, J. J. A. Mooij2; 1Dept Radioth University Medical Center, Groningen, Netherlands, 2Dept Neurosurgery University Medical Center, Groningen, Netherlands, 3Dept Nuclear Medicin University Medical Center, Groningen, Netherlands Objective: Complications due to radiosurgery (SRS) of intracranial meningiomas are reported in particular for parasagittal locations. Postradiosurgery peritumorous edema can give rise to increased intracranial pressure, seizures, or neurological deficits. Edema formation may be due to vasoactive factors secreted by the tumor and/or reactions related to vascular anatomy like disturbance of circulation. The latter may be caused by occlusion of superior sagittal sinus and bridging veins. Using multimodality imaging registered in BRAIN LAB Iplan/Brainscan complications of radiosurgery vascular occlusion may be anticipated. Material and Methods: A 26 year old female patient was considered for radiosurgery. She had a history of three Simpson 3 resections for a parasagittal meningioma (WHO grade I) within a time frame of 3 years. Two years after the last operation with excision of the tumor and the obliterated central part of superior sagittal sinus an asymptomatic small recurrence was suspected on MRI at the caudal part of sagittal sinus. Clinically the patient suffered from a persistent grade 3 paresis of the extensors of the right lower limb after the second craniotomy due to a venous infarction of left parietal cortex after tumor resection. Multimodality imaging was performed using contrast enhanced CT, GAD enhanced T1 3D MRI, DTI, MR venography, and 11C methionine PET (ECAT HR+). Studies were registered using IPLAN Image. Results: With 11C methionine PET meningioma was visualized and discriminated from the patent superior sagittal sinus identified by MR venography and 3D MRI. Using DTI with fiber tracking the corticospinal tract with the left motor strip was identified. With 3D MRI and MR venography draining veins from the left motor cortex were identified. SRS treatment planning showed high dose coverage of the entrance region of the cortical draining veins into the patent part of the superior sagittal sinus. We considered this an unacceptable risk factor for venous occlusion and additonal cerebral infarction and consequently an increase of paresis. Consequently the patient was not further evaluated for SRS, and she was offered fractionated stereotactic radiotherapy. Conclusions: We demonstrated that multimodality imaging registered in SRS planning could predict worsening of clinical symptoms due to anticipated SRS induced venous occlusion of draining veins into superior sagittal sinus. Multimodality imaging in stereotactic planning can provide important additional information, ultimately leading to alteration of treatment strategy. P080. BENIGN AND ATYPICAL MENINGIOMA METABOLIC DIFFERENCES BY HRMAS MOLECULAR PROFILING D. Monleon1, J. Morales2, J. Gonzalez-Darder3, F. Talamantes3, C. López-Ginés2, B. Celda2, M. Cerda-Nicolas3,2; 1Fundacion Investigacion Hospital Clinico Universitario Valencia, Valencia, Spain, 2University of Valencia, Valencia, Spain, 3Hospital Clinico Universitario Valencia, Valencia, Spain Purpose: Meningiomas add up to 30% of CNS tumors. Atypical meningiomas show a high index of recurrence 5 years after complete resection. Sometimes, meningiomas with histological diagnosis of benign meningioma show clinical characteristics of atypical meningioma. Additional criteria for better classification of meningiomas will improve clinical decisions like resection extension, additional radiotherapy needs, treatment selection, and patient follow up strategy after surgery. In this communication, we show differences in molecular profiles based on High Resolution Magic Angle Spectroscopy (HRMAS) spectra of 30 meningioma biopsies for the distinction between benign and atypical meningiomas. Samples and Methods: HRMAS spectra and consequent biochemical profile determination were obtained for 30 samples of human meningioma tissue (20–40 mg), of which 23 were benign and 7 were atypical. The whole HRMAS study was performed at 4°C. All samples were analyzed by post-HRMAS histopathology to assess the tissue integrity and double validate histological diagnosis. Statistical analysis was performed using in-house MATLAB scripts and the LIBRA statistical multivariate analysis library. One orthogonal component removal was calculated in ramdonly chosen 50% of cases and then applied to the remaining 50%. Principal component analysis (PCA) was applied to the set of spectral vectors. Principal components chosen explained at least 90% of the variance. Results: NMR spectra showed narrow line widths and adequate signal-to-noise ratios with well resolved spin-spin multiplicities. The comparison among spectra shows clear differences between benign and atypical meningiomas. The phospholipid pattern and other well known signals like alanine and lactate seem to have some correlation with the meningioma grade. Additionally, some signals belonging to unsaturated fatty acids seem to also discriminate the two groups of tumors. PCA analysis show major difference between benign and atypical meningioma for PC1 which major contributions are lactate, glutamate, unsaturated fatty acids, and the peaks in the choline region. Discussion/Conclusion: HRMAS allows discriminating between molecular profiles of benign and atypical meningiomas. The use of orthogonal signal correction allows to remove spectral component which variations are orthogonal to the diagnosis variable (sample degradation, sample contamination, etc). Metabolic discrimination between benign and atypical meningioma include the levels of phospholipids, glutamate, and fatty acids, which have been associated in previous studies to proliferation, recurrence, and partial necrosis, respectively. These metabolites may be the basis for a non-invasive classification of benign and atypical meningioma. Addition of new cases would probably improve the outcome of the classification method. P081. METABOLIC PROFILING OF PEDIATRIC BRAIN TUMORS BY HRMAS S. Cuellar1, J. Morales2, J. Calvar3, H. Martinetto3, B. Celda2,4, M. Cerda-Nicolas5, D. Monleon6; 1Institute of Physics Gleb Wataghin, State University of Campinas, Brazil, Campinas, Brazil, 2University of Valencia, Valencia, Spain, 3Fundacion Lucha Enfermedades Neurologicas de la Infancia, Buenos Aires, Argentina, 4CIBER of Bioenginery, Biomaterials and Nanomedicine, Zaragoza, Spain, 5Servicio Anatomia Patologica. Hospital Clinico Universitario Valencia, Valencia, Spain, 6Fundacion Investigacion Hospital Clinico Universitario Valencia, Valencia, Spain Introduction: The study of pediatric brain tumor metabolic profiles may help in the understanding of the disease. Valuable information about the metabolites enrolled in the disease can enhance our knowledge in this respect. High-resolution magic angle spectroscopy (HRMAS) is nowadays being broadly applied in metabolomics of intact tissues and cells, and has been successfully applied to the classification of different types of cancers. Subtle biochemical changes can be detected in intact tissues by HRMAS revealing the status of tumor microheterogeneity, unveiling tumor metabolic alterations before they are morphologically detectable. Those changes can also be correlated to histopathological features and diagnosis. In this work, we present metabolic profiles of pediatric brain tumors by HRMAS and possible correlations with the different tumor types and grades. Methods: HRMAS spectra were measured at 4°C on 22 samples of tumor tissue (17–33 mg) from pediatric patients (1–15 years old). The study included 8 medulloblastomas, 6 pilocytic astrocytomas, 3 low-grade astrocytomas, and 5 ependymomas. Diagnosis was confirmed histopathologically in all samples using standard protocols. Besides the comparisons between tumor groups, correlation with tumor grade was explored. Results: HRMAS spectra showed increased resolution and SNR compared to in-vivo MR spectroscopy (MRS). Choline compounds, which are highly overlapped in in-vivo spectra, were resolved by ex-vivo HRMAS. All aminoacids were identified, including relevant glutamine and glutamate. Good agreement between metabolites detected ex-vivo and in-vivo was observed. Some metabolite resonances showed significant differences between tumor groups. Conclusions: Agreement between in-vivo and ex-vivo MRS suggests that HRMAS can improve resolution and provide a link between in-vivo spectroscopy and neuropathologycal analysis. Particular attention should be placed in Choline compounds, Glutamate, Glutamine and GABA which are often unresolved in common clinical scanners. Some metabolites not previously detected by `in vivo' spectroscopy showed also some potential as biomarkers of tumor type and grade but their metabolic role in the disease is not well understood yet. Overall, we achieved metabolic discrimination between pediatric tumors according to the PCA. Our work suggests that HRMAS spectroscopy is a helpful technique to find metabolic patterns in pediatric brain tumors, to discriminate among tumor groups, and to correlate them with pathological pathways. The potential of the method as support to the histopathological analysis is also suggested. P082. VALUE OF DIFFUSION-WEIGHTED MR-IMAGING FOR DIFFERENTIATION OF INTRACEREBRAL ABSCESSES S. W. Brehmer, Ö. Krischek, M. Skalej, R. Firsching; Medizinische Fakultät, Magdeburg, Germany Objective: Brain abscesses are rare and often unrecognized. Gold standard in diagnosis is MR-imaging but the differentiation between gliomas and cerebral metastasis of other tumors is still a not well solved problem. Diffusion-weighted imaging in combination with the determination of apparent diffusion coefficient seems to be a useful help. We subsequently present our experiences with this type of imaging. Patients and Methods: We examined a group of 83 patients with 7 brain abscesses, 33 gliomas, and 43 intracerebral metastases. Results: In the abscess group was one false-positive and one false-negative result. In the other groups all results were right positive. One patient with a cavernoma showed a false-positive result with a hyperintensity on DWI and a reduced apparent diffusion coefficient. The false-negative result was seen in a patient with a frontal sinus fracture and a posttraumatic cerebritis. Conclusion: Diffusion weighted MR-imaging has a great value for the identification of brain abscesses. Problematic is the registration of small, fast regressive lesions and early states of cerebritis. P083. RECURRENT GLIOBLASTOMA OR RADIO NECROSIS? DIAGNOSTIC PITFALLS, DEMONSTRATED BY A CASE REPORT H. P. Bienfait1, W. A. van den Brink2; 1Gelre Hospitals, Apeldoorn, The Netherlands, 2Isala Klinieken, Zwolle, The Netherlands A 60 year old patient was diagnosed and treated for glioblastoma multiforme in 2005. In August 2005 the only presenting symptoms were migraine like visual complaints. In September 2005 occipital debulking was performed and followed by radiotherapy combined with chemotherapy and chemotherapy with temozolamide according to the Stupp protocol. She remained stable until May 2007. Control MRI of the brain showed a contrast enhancing lesion at the site of the previous tumor. At first there were no physical complaints, but because of progressive hemianopsia and partial visual seizures, treatment with temozolamide was started based on the diagnosis “recurrent Malignant Glioblastoma.” After the first course of temozolomide, chemotherapy was discontinued due to side effects and based on second thoughts about the correct diagnosis. A differential diagnosis of radionecrosis, mimicking the recurrence of tumor, was considered. All clinical symptoms and the findings on MRI also could be attributed to a diagnosis of radionecrosis. It left us with a clinical dilemma, since recurrent glioblastoma warrants a totally different aproach regarding therapy, opposed to radionecrosis. Several ancillary investgations were made: MR spectroscopy, PET scanning, and expert opininion (based on symptoms and MRI findings) suggested a diagnosis of radionecrosis. Based on these findings a wait and see policy was initiated, with frequent control MRI's. At the end of 2007 the size of the enhancing lesion had grown, and the patient was increasingly steroid dependent. Then a descision was made to perform another debulking operation with two objectives: To decompress and to obtain PA material. Craniotomy followed in February 2008, resulting in clinical improvement in providing the PA diagnosis of recurrent glioblastoma. In summary this case demonstrates the difficulties in distinguishing radionecrosis from the recurrence of glioblastoma multiforme. MR spectroscopy and PET scanning were not helpful, maybe even harmful in making the correct diagnosis. The patient will resume chemotherapy after recovering from her operation and steroid myopathy. The role of MR spectroscopy and PET scanning for distinguishing recurrent gliobastoma from radionecrosis will be discussed. P084. THE ROLE OF ADVANCED MRI TECHIQUES IN ASSESSING LOW-GRADE GLIOMAS: PRELIMINARY RESULTS A. Erbetta, M. E. Eoli, F. Ghielmetti, M. Grisoli, M. Farinotti, C. Falcone, B. Pollo, G. Broggi, F. Di Meco, A. Boiardi, G. Finocchiaro, S. Guzzetti, G. Filippini, M. Bruzzone; C. Besta, Milan, Italy Purpose: Prospective radiological grading of primary gliomas has inherent limitations but can provide relevant informations for the clinical management of the patients. Sensitivity of conventional MRI in defining the grade of gliomas ranges from 55.1 to 83% (Bulakbasi N. 2004, Zonari P. 2007, Law M 2003). To assess the accuracy of perfusion (PWI), diffusion (DWI), and proton-spectroscopy, we collected all patients with MRI suggesting glioma in absence of necrosis, relevant edema, and enhancing volume < 30% total tumor volume, from December 2006 to December 2007. Methods: Soon before surgery, 39 patients (11 m,. 5 f,. age: 26–77) were investigated by 1.5 T MRI with a protocol including DWI, PWI, and proton spectroscopy. ROI analyses were performed on ADC and rCBV maps on the different T2 imaging portions of the tumor and on the contralateral normal region. After surgery histopathological analysis confirmed the diagnosis of low-grade glioma in 26 patients (4 fibrillary astrocytoma, 5 oligodendroglioma, 15 oligoastrocytomas, 1 pilocytic astrocytoma, 1 ganglioglioma). Other patients had a grade III (7 anaplastic oligoastrocytomas, 3 anaplastic astrocytomas) and grade IV (3 pts.) gliomas. Results: Correct identification of tumor grade was performed in 80% (31/39) on the basis of preoperative conventional MRI. Association of advanced MRI techniques allowed to increase this fraction to 87% of the cases (34/39). Fibrillary astrocytomas have high ADC value (1.3–1.5) and low rCBV values (0.4–1.1). Oligoastrocytomas grade II had ADC values ranging between 1.8–3 and rCBV values ranging between 0.3–1.4 with respect to contralateral normal values. Cho/Cr ratio was < 1 in all low-grade tumors except for oligodendroglioma. Oligodendroglioma is characterized by high value of rCBV (0.9–3.7, mean 1.9) and high Cho/Cr ratio. GBM had high rCBV (0.8–1.6, mean 1.5) and ADC (0.5–1.6, mean 1.3) These preliminary results confirm the diagnostic role of advanced MRI in association with standard imaging. The limitation is differentiation between grade II and III tumors. Threshold values and ROI positioning into the lesion and in peritumoral tissue is of critical relevance. P085. FLOW CYTOMETRY STUDY OF THE DNA PLOIDY AND S-PHASE IN BRAIN TUMORS G. A. Alexiou, G. Vartholomatos, A. P. Kyritsis, K. S. Polyzoidis, S. Voulgaris; University Hospital of Ioannina, Ioannina, Greece Objective: The objective of this study was to investigate flow-cytometric DNA values of intracranial tumors, and to establish DNA analysis as a potential prognostic parameter. Material and Methods: We prospectively evaluated twenty-one patients (9 males, 12 females, mean age 60.4 years) with brain tumors. All patients had been operated on. The diagnosis was glioblastoma multiforme (7), anaplastic astrocytoma (1), typical meningioma (8), anaplastic meningioma (2), metastasis (2), and hemangioblastoma (1). Flow cytometry analysis was performed in the fresh tumor tissue specimens. The presence of DNA ploidy and the percentage of cells in G0/G1, S, and G2/M phases of the cell cycle were measured for each patient. Results: DNA distribution profiles in the tumors revealed 8 cases of diploidy and 13 cases of aneuploidy. Malignant tumors had a higher incidence of aneuploidy and higher S phase. Specially for meningiomas there was a positive correlation between meningioma's malignancy and level of aneuploidy (r=0.854, p<0.001). Conclusion: DNA ploidy and S phase as determined by flow cytometry are useful indicators of different biological behaviors in brain tumors. P086. VASCULAR ENDOTHELIAL GROWTH FACTOR AND ITS RECEPTOR VEGFR-1 IN GLIOBLASTOMA: TISSUE LEVELS AND THEIR RELATIONSHIP WITH SURVIVAL G. Reynes1, A. Parada2, V. Martínez-Sales2, V. Vila2, M. Martín1, E. Reganon2, I. Galeano3, R. Prat3, M. Peris3, E. Cárdenas3; 1Hospital Universitario La Fe, Dept. of Medical Oncology, Valencia, Spain, 2Hospital Universitario La Fe, Research Center, Valencia, Spain, 3Hospital Universitario La Fe, Dept. of Neurosurgery, Valencia, Spain Introduction and Objectives: In glioblastoma patients, tumor progression is related to angiogenesis, which is mediated in part by the vascular endothelial growth factor (VEGF-A) and its receptor VEGFR-1. In this study, VEGF-A and VEGFR-1 tumor levels, and their relationship with survival are analyzed. Materials and Methods: Levels of VEGF-A and VEGFR-1 were quantified in tumor tissue extracts of 25 glioblastoma patients. Quantification was performed using ELISA techniques (Human VEGF, Biosource and Quantikine Human sVEGFR1, R&D Systems). Survival data were analyzed using the Kaplan-Meier method. Patients were classified in two groups: Group A (survival <4 months), and Group B (survival ⩾4 months). The quartile 75 of survival was taken as a reference. Results: Median survival time was 7.83 months (CI 95%, 2.81–12.86). Patients who died from non-tumor-related causes were excluded from the analysis. In Group A (n=6), a positive trend to higher levels of VEGFR-1 was found, compared with Group B (n=13). (76.7±90.6 vs. 28.4±14.0 pg/mg protein; p=0.07). With regard to VEGF-A levels, no differences between Group A and Group B were observed (3.9 ±3.1 vs. 5.4±6.9 ng/mg protein). Conclusion: In glioblastoma patients, increased tissular levels of VEGFR-1 could be associated with reduced survival. Therefore, a greater number of cases should be studied in order to confirm these results. Supported in part by a Grant SEOM 2004. P087. INFLAMMATORY AND ANGIOGENIC MARKERS IN PATIENTS WITH GLIOBLASTOMA G. Reynes, A. Parada, V. Martínez-Sales, V. Vila, M. Martín, E. Reganon; Hospital Universitario La Fe, Valencia, Spain Introduction and Objectives: Some inflammatory markers, such as interleukin-6 (IL-6), are important mediators of tumor growth. Glioblastomas are tumors with significant vascular proliferation, inflammation, and necrosis; therefore these mechanisms must play a crucial role in the development of the disease. This study assesses pre-surgery circulating levels of inflammatory and angiogenic markers in glioblastoma patients. Material and Methods: The study included 25 patients with histologic diagnosis of glioblastoma. A group of 40 healthy volunteers with a similar distribution of age and sex was assessed as a control group. Samples of peripheral blood were collected from patients within one week before surgery. As inflammation markers, circulating levels of IL-6 (ELISA), tumor necrosis factor alpha (TNFα)(ELISA), fibrinogen (Fg) (turbidity assay), sialic acid (SA) (colorimetric enzymatic method) and C-reactive protein (CRP) (immunological agglutination technique) were quantified. As angiogenesis markers, serum levels of vascular endothelial growth factor (VEGF), and thrombospondin-1 (TSP-1) were determined by ELISA. Results are expressed as mean ±SD. Significance of the differences between means was evaluated using the Student's t-test for independent data. Results: We found a statistically significant increase in levels of all inflammatory markers in glioblastoma patients as compared with healthy controls (Fg: 333±178 vs. 238±44 mg/dl, p<0.001; SA: 77±25 vs. 53±9 mg/dl, p<0.0001; CRP: 16.6 ±27.8 vs. 1.6±1.7 mg/l, p<0.001; IL-6: 4.4±9.9 vs. 1.0±0.9 pg/ml, p<0.05). Levels of VEGF were significantly increased (VEGF: 226±218 vs. 146±101 pg/ml, p<0.05). However, TSP-1 levels in glioblastoma patients were not different with respect to the control group. The Pearson test was used for correlation analysis between inflammatory and angiogenic markers. A significant correlation between VEGF and Fg (R=0.65, p<0.01), and between VEGF and SA (R=0.51, p<0.05) was observed. Conclusion: Glioblastoma patients present significantly elevated levels of circulating inflammatory and proangiogenic markers. Supported in part by a Grant SEOM 2004. P088. THE SIGNIFICANT RELATIONSHIP BETWEEN MIB-1 LABELING INDEX AND S1P1 EXPRESSION CORRELATES WITH SURVIVAL IN GLIOBLASTOMA M. Nakada, Y. Yoshida, T. Harada, D. Kita, Y. Hayashi, N. Uchiyama, Y. Hayashi, J. Hamada; Kanazawa University, Kanazawa, Japan Objectives. Astrocytomas represent the most frequent primary tumors of the central nervous system. There are many reports on the clinical use of MIB-1 labeling index (LI) which linked to proliferative activity in astrocytomas, and its significance varies from one study to another. There are no molecules known which are directly linked to the MIB-1 LI in astrocytomas. The aim of this study was to evaluate the clinical value of MIB-1 LI in our human astrocytic tumor cases of different histopathological grades (WHO) and explore the molecules that could influence the MIB-1 LI. Materials and Methods. An immunohistochemical study of the MIB-1 proteins using the avidin-biotin-peroxidase method was performed and MIB-1 LI was determined in 70 astrocytomas (18 grade II, 10 grade III, and 42 grade IV). Clinical variables considered included gender, age, extent of surgical resection, tumor location and survival. In the same cases, EGFR, EGFRvIII, PTEN, PDGFR, and S1P1 (Sphingosine-1-phosphate 1 receptor) were detected and quantified by QRT-PCR, Western blotting, and immunohistochemistry. Results. Our data showed increasing values of MIB-1 LI with increasing grade of malignancy in astrocytomas (2.2% grade II, 5.4% grade III, and 26.7% grade IV). Kaplan-Meier survival curves for 40 patients with glioblastoma showed that high MIB-1 LI correlates with short survival (p<0.005). On the other hand, univariate analysis did not show any correlation between survival and gender, extension of surgical resection, tumor location, or patient's age at surgery. Among molecules tested, only low expression levels of S1P1 were significantly correlated with high MIB-1 LI in glioblastomas (p<0.05). Conclusions. This study establishes MIB-1 LI as an important predictor for the grade of astrocytic tumors and prognostic factor in human glioblastomas. S1P1 may play an important role in proliferative activity in glioblastomas. P090. CLINICOPATHOLOGICAL EVALUATION OF YKL-40 EXPRESSION IN GLIOMAS B. Pollo, E. Maderna, P. Gaviani, A. Salmaggi; Istituto Neurologico, Milano, Italy YKL-40 is a glycoprotein belonging to the chitinase family secreted by chondrocytes, synovial cells, neutrophils, and osteosarcoma cell lines. YKL-40 acts as growth factors for vascular endothelial cells and fibroblasts, and as adhesion and migration factor for vascular smooth muscle and endothelial cells. It also promotes degradation of ECM and angiogenesis and has a potential role in matrix remodeling like other molecules such as MMPs, laminin, collagen, and plasminogen. The function of YKL-40 protein in human glioma biology is unknown. It seems to be involved in tumor invasion and angiogenesis; it is expressed in infiltrating macrophages and in proliferating endothelial cells, and its expression shows correlation with survival time in patients with advanced cancer. Recent studies identified different expression of YKL-40 in the cytoplasm of tumor cells, blood vessels, extracellular matrix, and in reactive astrocytes in high-grade gliomas, whereas it was absent in low-grade gliomas and normal brain. On the hypothesis that this molecule is involved in the biology of a subset of glioblastoma and is a predictive marker of aggressive behavior, we performed an immunohistochemical and Western blot investigation on the expression and role of YKL-40 in 70 patients with glioma, to evaluate relationship with clinical outcome (time to tumor progression [TTP] and overall survival). The patients were 50 glioblastomas, 5 oligoastrocytomas, 5 anaplastic oligoastrocytomas, 3 astrocytomas, 3 anaplastic astrocytomas, 2 oligodendrogliomas, and 2 anaplastic oligodendrogliomas. We also investigated the co-expression of YKL-40 with EGFR, PTEN, p53, and gene metylation status of MGMT. Our results showed variable immunoreactivity for YKL-40 in glioblastoma tumor cells, and all low-grade gliomas were negatives. In some cases, positivity in proliferating endothelial cells and in reactive astrocytes was also detected. Co-expression with EGFR was observed in 25% and with MGMT in about 50% of glioblastoma. Western blot analysis was performed in the aim to evaluate the specifity of YKL-40 in 15 patients; YKL-40 showed a clear band at 40 kD with variable intensity. Clinical data now available for glioblastoma patients, suggest a correlation of YKL-40 expression with shorter time to tumor progression (median TTP 5.2 months), while tissues weakly positive or negative showed a longer median TTP (8.2 months). These findings suggest that YKL-40 is associated with higher grade astrocytic tumors and to shorter time to tumor progression in glioblastomas. P091. INVOLVEMENT OF WHITE MATTER VS. GREY MATTER IS PREDICTIVE OF PROGNOSIS AND CHEMOSENSITIVITY IN GLIOMATOSIS CEREBRI G. Kaloshi1, N. Martin-Duverneil2, R. Guillevin2, F. Laigle-Donadey2, Y. Marie2, S. Taillibert2, K. Mokhtari2, K. Hoang-Xuan2, J. Delattre2, M. Sanson2; 1UHC Mother Theresa, Tirane, Albania, 2GH Pitié-Salpêtrière, Paris, France In gliomatosis cerebri (GC), defined as a diffuse neoplastic glial cell infiltration of the brain, up-front chemotherapy is often proposed as an alternative to the radiotherapy. GC invades in various proportion both white matter (WM) and grey matter (GM), as reflected by the GM/WM ratio. The GM/WM ratio was estimated in 70 patients with GC (42 men and 28 women; median age 47 years) treated with up-front chemotherapy (13 PCV, 57 temozolomide). Median GM/WM was 30%. Compared to group B (33 patients with GM/WM>30%), the 37 patients from group A (defined as GM/WM⩽30%) had better performance status (p=0.04), higher response rate to chemotherapy (27/37 vs. only 9/33; p=0.0005), longer progression free survival (19.4 vs. 11.7 months, p=0.02), and longer overall survival (56.1 vs. 26.4 months; p=0.003). There was no significant correlation with histological subtype (oligodendroglial vs. astrocytic or mixed GC), grading, tumor localization, or laterality. The deletion of chromosomes 1p and 19q tended to be more frequent in group A (8/17 [47%] vs. 1/9 [11%] in group B [p=0.07]). These data suggest that GM/WM ratio is a prognostic and predictive marker in GC. P092. MNS16A MINISATELLITE GENOTYPES IN RELATION TO RISK OF GLIOMA AND MENINGIOMA AND TO GLIOBLASTOMA OUTCOME U. Andersson1, P. Osterman2, S. Sjöström1, C. Johansen3, R. Henriksson1, T. Brännström2, H. Broholm4, H. Collatz Christensen3, A. Ahlbom5, A. Auvinen6,7, M. Feychting5, S. Lönn8, A. Kiuru7, A. Swerdlow9, M. Schoemaker9, G. Roos2, B. Malmer1; 1Dept of Radiation Sciences, Oncology, Umea University, Umea, Sweden, 2Dept of Medical Biosciences, Pathology, Umea University, Umea, Sweden, 3Institute of Cancer Epidemiology, Danish Cancer Society, Copenhagen, Denmark, 4Dept of Pathology, The Centre of Diagnostic Investigations, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark, 5Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden, 6Dept of Epidemiology, Tampere School of Public Health, University of Tampere, Tampere, Finland, 7Dept of Research and Environmental Surveillance, STUK-Radiation and Nuclear Safety Authority, Helsinki, Finland, 8Dept of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm, Sweden, 9Section of Epidemiology, Institute of Cancer Research, Sutton, Surrey, United Kingdom The human telomerase reverse transcriptase (hTERT) gene is upregulated in a majority of malignant tumors. A variable tandem repeat, MNS16A, has been reported to be of functional significance for hTERT expression. Published data on the clinical relevance of MNS16A variants in brain tumors have been contradictory. The present population based study in Nordic countries and the UK evaluated brain tumor risk and survival in relation to MNS16A minisatellite variants in 648 glioma, 473 meningioma, and 1,359 age, sex, and geographically matched controls. By PCR based genotyping all study subjects with fragments of 240 or 271 bp were judged as having short (S) alleles and subjects with 299 or 331 bp fragments as having long (L) alleles. Risk of glioma or meningioma was estimated with logistic regression adjusting for age, sex, and country. Overall survival was analyzed using Kaplan-Meier estimates and equality of survival distributions using the log-rank test, and by Cox proportional hazard ratios. The MNS16A genotype was not associated with increased risk of occurrence of glioma or meningioma. For glioblastoma (GBM), overall survival differed significantly with MNS16A genotype, with median survivals of 15.3, 11.0, and 10.7 months for the LL, LS, and SS genotypes, respectively. The hazard ratio for death having the SS or LS genotype compared with the LL genotype was significantly increased, 2.05 95% CI (1.35–3.12). In contrast to a previous publication showing better survival for the MNS16A SS genotype, our data indicated a better outcome for the LL genotype. Collected data from our and previous studies indicate that the MNS16A genotype results are contradictory and that the genotype is likely to be of minor relevance for glioblastoma risk and outcome. P093. P53 AND CHEMOSENSITIVITY IN ASTROCYTIC GLIOMAS M. Blough, M. Westgate, D. Beauchamp, G. Cairncross; University of Calgary, Calgary, AB, Canada Over 2,000 Canadians are diagnosed yearly with glial neoplasms; treatment for many such tumors involves surgical resection then chemotherapy and radiotherapy. Recently, Hegi et al. demonstrated that patients with gliomas unable to repair lesions induced by the DNA alkylating agent temozolomide (TMZ), have a more favorable prognosis than those that maintain alkyl-repair capacity. Repair capacity was gauged by promoter methylation of the gene encoding MGMT, an alkyl-DNA repair protein: gene silencing by promoter methylation increases TMZ cytotoxicity. As such, expression of MGMT is a useful predictor of patient response to TMZ. However, not all responders in the Hegi study had methlyated tumors, so other markers of benefit from TMZ may exist. In the mouse, absence of the tumor suppressor p53 increases the sensitivity of astrocytes to DNA alklyating agents. Because altered p53 function is also common in human gliomas, we reasoned that p53 might be involved in determining glioma chemotherapeutic response: p53 regulates apoptosis and cell cycle arrest, so may affect sensitivity to DNA damage. We examined the effects of altering expression of p53 on cellular response to treatment with TMZ. RNAi for p53, Pifithrin, a p53 inhibitor, and the p53-targeting viral protein E6 were used to inhibit p53 function in glioma cell lines. Following exposure to TMZ cell viability was monitored and in all cases demonstrated that absence of p53 enhances the cytotoxic effects of TMZ. Based on this data, we predict that p53 expression status may be an independent predictor of response of glial cells to treatment with TMZ and, in addition to MGMT methylation status, might be a marker of benefit from TMZ therapy. P094. EXPRESSION OF INTEGRIN ALPHA V BETA 3 IN PATIENTS WITH HIGH AND LOW-GRADE GLIOMAS IS NOT RESTRICTED TO TUMOR ANGIOGENESIS O. Schnell1, B. Krebs2, A. Beer3, A. Romagna1, E. Wagner1, H. A. Kretzschmar2, J. Tonn1, R. H. Goldbrunner1; 1Dept. of Neurosurgery, Munich, Germany, 2Center for Neuropathology and Prion Research, LMU München, Munich, Germany, 3Dept. of Nuclear Medicine, Klinikum rechts der Isar, Technische Universität München, Munich, Germany Objective: The integrin alpha v beta 3 (αvβ3) has been appointed a key player in the angiogenesis of malignant gliomas. However, there is still a controversy about the expression and distribution of αvβ3 integrin due to malignancy. The aim of our study was to assess the extent and pattern of αvβ3 integrin expression within primary glioblastomas and low-grade gliomas. Methods: Immunohistochemical stainings from tumor samples (GBM: n=12; LGG: n=4) for detection of αvβ3 integrin (clone LM609) were performed simultaneously and automatically to reach a maximum of accuracy. Staining was quantified by a special imaging software, which was calibrated for this purpose to xenotransplanted human melanoma cells (M21) expressing αvβ3. Within a selected area, it measured (1) the mean intensity of the desired immunohistochemical staining and (2) the immunohistochemically positive fraction at a desired immunohistochemical staining intensity. To further analyze the distribution of the integrin subunits αv and β3, Western blot analysis from corresponding histological sections (GBM: n=20; LGG: n=5) was performed. The microvascular distribution to αvβ3 expression in these tumors was determined by co-staining with endothelial cell specific markers (CD31). Results: The expression of αvβ3 was found to be significantly higher in glioblastomas than in low-grade gliomas, whereby focal strong reactivity was restricted to glioblastomas only. Different glioblastomas show a very heterogeneous expression of αvβ3 integrin which ranges from slightly to very strong integrin expression similar to high expressing non-CNS tumors. Subsequent analysis revealed that not only endothelial cells contribute to the overall amount of αvβ3 integrin in the tumors. In malignant gliomas, more than three quarters of the overall integrin expression (about 85 %) derived from glial tumor cells. Moreover, Western blot analysis demonstrated a significant difference in the expression of the β3-integrin subunit between glioblastomas and low-grade gliomas. Conclusion: The presented data lead to new insights in the pattern of αvβ3 integrin in gliomas. Since antiangiogenic therapy with integrin αvβ3-antagonists has reached clinical trials for patients with malignant gliomas minute detection and quantification of αvβ3 integrin expression could be a prerequisite for selection of patients suitable for this kind of additional therapy. P096. EXPRESSION OF OCCLUDIN IN BRAIN TUMORS IS CORRELATED TO THE PERITUMORAL EDEMA AND SURVIVAL C. Kim, J. Cheong, K. Bak, J. Kim, S. Oh; College of Medicine, Guri Gyeonggi-Do, Republic of Korea A serious outcome of the patients with brain tumors is developed by peritumoral brain edema (PTBE). The development of PTBE is influenced by many factors including tight junction proteins, such as occludin. We studied the correlation with PTBE volume and survival time relevant to occludin expression in various pathology of brain tumors. Fresh-frozen specimens from sixty patients with brain tumor were obtained during surgery and confirmed pathologically. Occludin expression was investigated by Western blot analysis. PTBE volume was measured by using preoperative magnetic resonance image (MRI) and survival time in each patient was also estimated retrospectively. Occludin was detected in 41 (68.3%) brain tumors and the other 19 (31.7%) was not. Although it was revealed the lowest expression in high-grade gliomas, its expression was variable according to pathology of brain tumors (p > 0.05). The difference of PTBE volume between occludin-positive and negative brain tumors was significant (p = 0.002). The mean survival time was prolonged in occludin-positive tumors comparable to negative one (p = 0.001). This study suggests that occludin expression is well relevant to the PTBE development in brain tumors and may affect the prognosis for survival of patients. P097. MARKERS OF RECURRENCE IN MENINGIOMAS IDENTIFIED BY GENE EXPRESSION PROFILING E. Pérez-Magán1, C. Fiaño2, T. Ribalta3, J. García4, A. García-Claver1, Y. Campos-Martín1, Y. Ruano1, J. Hernández-Moneo1, M. Mollejo1, B. Meléndez1; 1Hospital Virgen de la Salud, Toledo, Spain, 2Complejo Hospitalario Xeral-Cíes, Vigo, Spain, 3Hospital Clinic, Barcelona, Spain, 4MD Anderson Internacional, Madrid, Spain Meningiomas account for about 24–30% of primary intracranial tumors. Most of these tumors are benign (WHO grades I and II) and can be cured by surgical resection. Recurrence, however, represent the major factor influencing patient's outcome and occur between 10% and 25% of the cases undergoing complete resection of the tumor. The molecular mechanisms associated with recurrence are still unclear. In order to identify predictive candidate target genes and/or molecular markers of recurrence we performed gene expression profiles in recurrent and primary tumors. A total of 45 patient samples were analyzed by using oligonucleotide microarrays, including 4 samples of nonneoplastic postmortem meninges, 17 WHO grade I, 17 WHO grade II, and 7 recurrent (WHO grades I and II) tumors. Expression profiles of primary tumors was compared to that of recurrences. Statistical analyses were performed by using GEPAS (CIPF, Valencia, Spain) and GSEA (Broad Institute, Cambridge, Massachusetts). Using a discriminant approach analysis we identified genes with differential expression between recurrent and primary tumors (FDR<0.15). These genes were related to the WNT, MAPK, TGF-β signaling pathways, regulation of actin cytoskeleton, and focal adhesion. Our results revealed candidate markers associated with recurrence that were tested in tissue arrays. Additional studies of these genes are guaranteed to provide useful diagnostic and prognostic markers. P098. SERUM FERRITIN—A GLIAL TUMOR MARKER H. Jaksch1, N. Bresgen1, S. M. Golaszewski2,3, W. Kleindienst2, P. Strasser2, K. Bordihn4, R. Al-Schameri4, S. Spiegl-Kreinecker5, B. Richling4, G. Ladurner2; 1University of Salzburg, Department of Cell Biology, Salzburg, Austria, 2Department of Neurology, Paracelsus Medical University, Salzburg, Austria, 3fMRI Lab, Department of Psychiatry, Medical University, Innsbruck, Austria, 4Department of Neurosurgery, Paracelsus Medical University, Salzburg, Austria, 5Department of Neurosurgery, Wagner Jauregg Clinic, Linz, Austria Several clinical reports have described a correlation among different kinds of cancer and increased serum levels of ferritin which is supposed to represent a non-specific tumor marker. With respect to brain tumors, this also holds true for neuroblastomas, whereas detailed information regarding the release of ferritin from glial tumors is still missing and the role of ferritin in brain tumor development is still poorly defined. Besides its main function as a cellular iron storage protein, certain secreted ferritin isoforms—i.e., heavy(H)-chain rich acidic isoferritins—have been described which reveal immunosuppressive properties and are able to stimulate apoptosis. Notably, the generation of reactive oxygen species appears of high relevance for ferritin mediated apoptosis which also involves the upregulation of p53 and stimulation of the Fas (CD95) pathway. Here we show that culture supernatants (CM) collected from certain cell lines derived from human glial tumors as well as rat glioma C6-CM are able to stimulate apoptosis. Since this effect is strongly inhibited by neutralizing antibodies raised against the ferritin H-chain, this effect is supposed to be mediated by H-chain rich isoferritins released from the cells into the culture medium. Intriguingly, not all examined tumor cell line culture supernatants as well as those obtained from primary, non-transformed mouse astrocytes show an apoptosis inducing potential. Notably, addition of the anti H-chain antibody to these CM uncovered a proliferation stimulating activity which has to be characterized in detail. P099. INTEGRIN LINKED KINASE (ILK) IS A PROGNOSTIC FACTOR IN HUMAN GLIOMAS IMPLICATED IN TUMOR RESISTANCE TO THERAPY L. Bello1, C. Verpelli2, V. Lucini3, G. Bertani4, C. Sala5; 1Neurosurgery, University of MIlano, ELAT, Milano, Italy, 2Neurosurgery, University of Milano, ELAT, Milano, Italy, 3Pharmacology, University of Milano, Milano, Italy, 4Neurosurgery, Univeristy of Milano, ELAT, Milano, Italy, 5Pharmacology, University of Milano, ELAT, Milano, Italy Objective: To detect molecular determinants associated with the development of glioma resistance to anti-angiogenesis and its therapeutic and clinical significance. Angiogenesis inhibitors inhibit the growth of experimental malignant gliomas in vivo and induce dynamic changes in tumor vasculature. Vascular regression is followed by vascular normalization afterwhich the tumor vasculature starts to actively grow. Methods: Proteomics, immunofluorescence. Results: By proteomics, we initially investigated the pattern of protein expression associated with the administration of one inhibitor, PF-4/DLR, that acts simultaneously on angiogenesis and invasion. The phase of normalization was associated with the increased expression of integrin linked kinase (ILK) and of its respective downstream molecules, expression of which was instead reduced during the phase of vascular regression. ILK expression was associated with an increased expression of molecules mediating signal transmission from integrin and growth factor receptors and implicated in cell growth/survival, cell cycle progression, tumor invasion, and angiogenesis. These data suggested ILK as one of the proteins associated with the development of resistance to anti-angiogenesis. We then silenced the activity of ILK to enhance the response of the tumor vasculature to anti-angiogenesis. By the use of siRNA, we started the silencing at the beginning of the phase of vessel normalization to prolong the period of normalization. PF-4/DLR was administered in combination with ILK siRNA, resulting in a significant increase in the duration of the phase of vessel normalization, and in a longer glioma growth control. This was associated with a decrease expression and activation of the downstream molecules associated with ILK activity. Finally, to determine the clinical relevance of these findings, we investigated the expression of ILK in samples of human gliomas of different histological grade and subtypes, from primary tumors or after treatment with chemo or radiotherapy. ILK expression correlated with tumor grade and subtypes. Its expression was higher in recurrent than in primary tumors, and particularly in those which were resistant to radio or chemotherapy. In high-grade gliomas, ILK expression correlated with time to recurrence. Conclusion: ILK is a prognostic factor implicated in glioma resistance to therapy. P100. SPHINGOSINE-1-PHOSPHATE1 RECEPTOR CORRELATES WITH SURVIVAL OF PATIENTS WITH GLIOBLASTOMA: ROLES OF SPHINGOSINE-1-PHOSPHATE1 RECEPTOR IN GROWTH OF GLIOBLASTOMA CELL LINES Y. Yoshida1, M. Nakada1, T. Harada1, N. Sugimoto2, Y. Hayashi1, D. Kita1, N. Uchiyama1, Y. Hayashi1, J. Hamada1; 1Department of Neurosurgery, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan, 2Department of Molecular Vascular Physiology, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan Sphingosine-1-phosphate (S1P) is a bioactive lipid that signals through a family of five G protein-coupled receptors, termed S1P1-5, and regulates cellular proliferation, migration, survival, and angiogenesis. We investigated the expression and the role of S1P receptors in human astrocytomas. Astrocytomas of various histologic grades expressed four types of S1P receptors, S1P1, S1P2, S1P3, and S1P5 by quantitative RT-PCR analysis. Expression of S1P1 receptor was significantly lower in glioblastomas than those in normal brains and low-grade astrocytomas. Immunoblot using specific antibody against S1P1 receptor showed that normal brain, low-grade astrocytomas and anaplastic astrocytomas expressed more S1P1 receptor protein than glioblastomas. Immunohistochemistry showed that S1P1 receptor was immunolocalized predominantly to the majority of astrocytes in the normal brain, but no staining was observed in neoplastic astrocytes in glioblastoma specimens. Patients with glioblastomas whose tumors showed high levels of S1P1 receptor expression had 76% survival rate at 1 year, whereas those with low levels of S1P1 had 37% survival rate at 1 year. Furthermore, we examined the mechanism of S1P1 receptor pertaining to glioma cell proliferation and migration by manipulating S1P1 gene in glioma cell lines. Forced expression of S1P1 receptor in low expressor cell lines (U87, U251) resulted in decreased cell growth concomitant with the activation of S1P1 receptor. Cells transfected with small interfering RNA of S1P1 receptor in high expressor cell lines (T98G, G112) promoted cell proliferation. In the migration assays, no significant change was observed by either overexpressing or knocking down S1P1 receptor in glioma cell lines. This is the first demonstration that S1P1 receptor signaling negatively controls cell proliferation in glioblastomas. Dysregulation of S1P1 receptor expression or function may underlie glioma proliferation but not migration. P101*. N29 AND N32 RAT GLIOMA MODELS EXHIBIT CANCER STEM CELL PROPERTIES S. Gunnarsson1,2, D. Bexell1,2, E. Visse1, L. G. Salford1, P. Siesjö1, J. Bengzon1,2, A. Darabi1; 1The Rausing Laboratory, Neurosurgery, Lund, Sweden, 2Lund Strategic Research Center for Stem Cell Biology and Cell Therapy, Lund, Sweden Cancer stem cells (CSCs) are defined as a subpopulation of cells within a tumor that give rise and maintain the entire tumor. CSCs have been discovered in leukaemia, breast, colon, and prostate cancer and recently also in various brain tumors including glioblastoma multiforme (GBM). GBM, the most common and most aggressive primary brain tumor in adults, is a highly anaplastic tumor composed of more or less poorly differentiated cells with extremely variable histological appearances. We investigated cancer stem cell properties in two established rat glioma models, N29 and N32, induced by transplacental ethyl-nitroso-urea injection. This mode of tumor induction has previously been proposed to mimic the development of human glioblastomas from subventricular zone stem or progenitor cells. Both N29 and N32 cells readily form free-floating spheres with self-renewing capacity when cultured in specialized stem cell medium. N29 and N32 express the putative cancer stem cell marker CD133 and the stem/progenitor markers musashi and nestin in vitro concomitantly with the expression of the neural lineage markers glial fibrillary acidic protein, doublecortin, ßIII-tubulin, and CNPase. When subjected to differentiating conditions, neither N29 nor N32 changed their phenotype. Importantly, both models show a very high clonogenicity in vitro and a robust tumorigenicity in vivo. Unsorted single N29 and N32 tumor cells formed clones with a very high frequency in vitro, and intracerebral inoculation of as few as 10 N29 and N32 tumor cells, respectively, gave rise to a tumor. This study shows that both N29 and N32 glioma cells display properties of CSCs. In contrast to other reports of cancer stem cell-like cells in similar experimental gliomas, we demonstrate that sphere formation does not necessarily alter the CSC features of the tumor models. We use these two tumor models to develop and improve immunotherapy of glioblastoma in ongoing clinical trials. Thus, we conclude that our experimental therapies are directed against CSC-containing brain tumors which have a close resemblance to glioblastoma. P102*. RISK POTENTIAL OF AUTOLOGOUS MESENCHYMAL STEM CELL TRANSPLANTATION IN GLIOBLASTOMA PATIENTS C. Schichor, E. Soballa, J. Tonn, R. H. Goldbrunner; Dept. Neurosurgery, Munich, Germany Objective: Adult human mesenchymal stem cells have been successfully used in animal experiments as a source for cell based strategies. Their differentiation potential, their expandability as well as their selective recruitment by malignant glioma cells makes them ideal candidates for cell-based treatment strategies. Aim of our study was to evaluate whether in vitro expansion of stem cells or interaction of stem cells with malignant cells bears an immanent risk of tumor formation. Methods: Adult human mesenchymal stem cells (hMSCs) were obtained from bone marrow donations of healthy volunteers. Cells have been characterized by FACS analysis and differentiation assays. Kept in standard culture conditions, cell morphology, proliferation rates, and potential anchorage independent growth was analyzed. Cells were implanted into immune-deficient rats subcutaneously as well as intraveneously. Expression level of telomerase as an indicator for immortalization was detected using RT-PCR. Results: Isolated cells from healthy donors were characterized as mesenchymal stem cells by typical marker expression in FACS analysis and by differentiation into bone or fat producing lineages. In vitro, an initial low proliferation rate was followed by a replicative phase of senescence with no detectable proliferation. Cells of samples, which overcame the state of senescence, showed a marked increase in proliferation rate, a changed morphology and anchorage independent growth potential as an indicator for an acquired malignant potential. In animal experiments, these transformed cells showed local tumor formation. RT-PCR showed signs of hTERT-overexpression in malignant transformed cells. Conclusion: Stem cell isolation from glioma patients for autologous reimplantation after transfection as a cellular vector bears a potential risk of stem cell tumor induction. Further studies are necessary in order to minimize this risk, inherent in expansion of stem cells in vitro. P103. GLIAL PROGENITOR-LIKE PHENOTYPE IN LOW-GRADE GLIOMA AND ENHANCED CD133-EXPRESSION AND NEURONAL LINEAGE DIFFERENTIATION POTENTIAL IN HIGH-GRADE GLIOMA J. Rebetz1, D. Tian1, A. Persson2, B. Widegren1, L. G. Salford1, E. Englund3, D. Gisselsson4, X. Fan1; 1The Rausing Laboratory, Lund, Sweden, 2Department of Pathology, Lund University Hospital, Lund, Sweden, 3Department of Pathology, Lund University, Lund, Sweden, 4Department of Clinical Genetics, Lund University Hospital, Lund, Sweden Background: While neurosphere- as well as xenograft tumor-initiating cells have been identified in gliomas, the resemblance between glioma cells and neural stem/progenitor cells as well as the prognostic value of stem/progenitor cell marker expression in glioma are poorly clarified. Methodology/Principal Findings: Viable glioma cells were characterized for surface marker expression along the glial genesis hierarchy. Six low-grade and 17 high-grade glioma specimens were flow-cytometrically analyzed for markers characteristics of stem cells (CD133); glial progenitors (PDGFRα, A2B5, O4, and CD44); and late oligodendrocyte progenitors (O1). In parallel, the expression of glial fibrillary acidic protein (GFAP), synaptophysin, and neuron-specific enolase (NSE) was immunohistochemically analyzed in fixed tissue specimens. Irrespective of the grade and morphological diagnosis of gliomas, glioma cells concomitantly expressed PDGFRα, A2B5, O4, CD44, and GFAP. In contrast, O1 was weakly expressed in all low-grade and the majority of high-grade glioma specimens analyzed. Co-expression of neuronal markers was observed in all high-grade, but not low-grade, glioma specimens analyzed. The rare CD133 expressing cells in low-grade glioma specimens typically co-expressed vessel endothelial marker CD31. In contrast, distinct CD133 expression profiles in up to 90% of CD45-negative glioma cells were observed in 12 of the 17 high-grade glioma specimens and the majority of these CD133 expressing cells were CD31 negative. The CD133 expression correlates inversely with length of patient survival. Surprisingly, cytogenetic analysis showed that gliomas contained normal and abnormal cell karyotypes with hitherto indistinguishable phenotype. Conclusions/Significance: This study constitutes an important step toward clarification of lineage commitment and differentiation blockage of glioma cells. Our data suggest that glioma cells may resemble expansion of glial lineage progenitor cells with compromised differentiation capacity downstream of A2B5 and O4 expression. The concurrent expression of neuronal markers demonstrates that high-grade glioma cells are endowed with multi-lineage differentiation potential in vivo. Importantly, enhanced CD133 expression marks a poor prognosis in gliomas. P104. THERAPEUTIC EFFECT OF SUICIDE GENE-TRANSFERRED MESENCHYMAL STEM CELLS IN A RAT GLIOMA MODEL K. Yoshida1, H. Kosaka1, T. Ichikawa1, H. kambara1, S. Inoue1, T. Maruo1, K. Kurozumi2, K. Nakamura3, H. Hamada3, I. Date1; 1Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan, Okayama, Japan, 2Department of Neurosurgery, Ohio State University, Columbus, OH, United States, 3Department of Molecular Medicine, Sapporo Medical University, Sapporo, Japan, Sapporo, Japan Objective: Mesenchymal stem cells (MSC) have received much attention as therapeutic vehicle because they have migratory capacity toward the malignant glioma cells. In the present study, we evaluated new therapeutic strategy by using combination of intratumoral inoculation of MSC expressing suicide gene (cytosine deaminase) and 5-FC administration on malignant glioma cells. Methods and Results: At first, the cell migration assay was performed using double chamber dishes. MSCs were placed in the upper chamber with 8-μm pores, and 9L cells were placed in the lower well. We could confirm that MSCs possessed significant migratory capacity for glioma cells in vitro. Next, to evaluate the antitumor effect of 5FC/MSC-CD system in vitro, 9L cells were cocultured with MSC-CDs in the medium containing 5FC. We could find that this system had antitumor effect on the glioma cells. In addition, to confirm bystander effect, which did not require cell-to-cell contact, chemosensitivity assay was performed using double chamber dish. MSC-CDs were placed in the upper chamber with 0.4-μm pores, and 9L cells were placed in the lower wells in the medium containing 5FC. We could investigate strong bystander effects of this system. Following these in vitro studies, we investigated the migratory capacity of MSCs in vivo. 9L cells were implanted into the right basal ganglia, and then MSCs were injected directly into the implanted glioma. We comfirmed that MSCs could migrate and proliferate in the established tumor by immunohistochemical analysis. To evaluate antitumor effect of 5FC/MSC-CD system in vivo, MSC-CDs were inoculated into the center of already implanted 9L tumor through the same injection tract and treated by systemic administration of 5FC. The survival term of tumor implanted rats in the treatment group was significantly longer than that in the control group. Conclusion: We demonstrated the migratory capacity of MSCs and the antitumor effect of 5FC/MSC-CD in vitro and in vivo. Molecular therapy employing MSCs as a targeting vehicle would be promising as a new therapeutic approach for highly invasive malignant glioma. P105. IMMUNOLOGICAL CHARACTERIZATION OF CELLS DERIVED FROM NEUROSPHERE CULTURES OF GLIOBLASTOMA MULTIFORME T. Avril1, G. Gapihan1, S. Saikali2, E. Vauleon1, A. Hamlat3, S. Diabira3, V. Quillien1,4; 1CRLCC Centre Eugène Marquis, Rennes, France, 2Dpt of Pathology, CHU Pontchaillou, Rennes, France, 3Dpt of Neurosurgery, CHU Pontchaillou, Rennes, France, 4UMR6061, CNRS, University of Rennes 1, Rennes, France Glioblastoma multiforme (GBM) is a brain tumor with a very poor prognosis due to inevitable recurrence. During the last few years, a contingent of cells within the tumor, so-called stem-like tumor cells (STC), has been characterized in GBM. These cells have similar properties to stem cells and can, with a limited number of cells injected in vivo in animals, recapitulate an entire initial tumor. STC are also resistant to current radio- and chemo-therapeutic treatments in vitro. Therefore, STC are considered to play a major role in the recurrence observed in GBM patients. These cells may be appealing targets for new therapeutic approaches such as immunotherapy. In order to expand STC, tumor samples from GBM patients are dissociated mechanically and cultured in a serum-free medium previously described (Reynolds & Weiss, 1992) in presence of EGF and bFGF. After emergence of the first neurospheres (between 4 to 21 days), cells are dissociated with trypsin. Neurospheres cultures are then passaged every 21 days after trypsin dissociation. Up to now, we have tried to expand STC from 21 GBM samples and 4 neurosphere cultures have been amplified up to 5, 7, 7, and 10 passages. Phenotypic analyses show that cells derived from all the neurosphere cultures strongly express nestin and A2B5 markers. Three out of four express CD133 but only one at high expression level. Concerning the immunological characterization, cells derived from all neurosphere cultures express HLA class I molecules, essential for specific recognition of tumor cells by cytotoxic T lymphocytes. In addition, a tumor antigen, EGFRvIII, previously described in GBM, is found in one neurosphere culture. In conclusion, these preliminary results show that STC are potentially interesting targets for immunotherapy. P106. EVALUATION OF TUMORIGENICITY OF HUMAN FETAL NEURAL STEM/PROGENITOR CELLS AFTER LONG-TERM IN VITRO MAINTENANCE D. Ogawa1,2, Y. Okada2,3, M. Okada1, S. Ohkubo1, K. Miyake1, Y. Kanemura4, M. Ito5, T. Tamiya1, S. Nagao1, H. Okano2; 1Department of Neurological Surgery, Faculty of Medicine, Kagawa University, Kagawa, Japan, 2Department of Physiology, School of Medicine, Keio University, Tokyo, Japan, 3Department of Neurology, Graduate School of Medicine, Nagoya University, Aichi, Japan, 4Institute for Clinical Research, Osaka National Hospital, National Hospital Organization, Osaka, Japan, 5Central Institute for Experimental Animals, Kanagawa, Japan It is important to expand human neural stem/progenitor cells (hNS/PCs) in vitro to obtain large amounts for clinical applications. However, the long-term maintenance of hNS/PCs in vitro may cause DNA damage due to repeated passages, which might result in malignant transformation. Furthermore, hNS/PCs and their immediate progeny are considered to carry a credible risk for malignant transformation, because many of the molecular determinants that regulate normal neurogenesis are also apparently involved in tumorigenesis. However, the in vivo tumorigenicity of hNS/PCs, which are maintained for more than 250 days in vitro (DIV), has never been described and is still uncertain. Therefore, we examined the in vitro properties of hNS/PCs cultured for approximately 250 DIV (hNS/PCs-250) and approximately 500 DIV (hNS/PCs-500), and transplanted them into the striatum of immunodeficient mice to evaluate their tumorigenicity by continuous monitoring with bioluminescence imaging (BLI) for approximately 6 months in combination with conventional histology. In vitro, the hNS/PCs-250 exhibited a higher growth rate and greater neurogenic potential than hNS/PCs-500, which showed greater gliogenic potential. In vivo, both hNS/PCs-250 and -500 differentiated into neurons and astrocytes 4 weeks after being transplanted into immunodeficient mice, and hNS/PCs-250 exhibited better survival than hNS/PCs-500 at this time point. We also monitored hNS/PCs-250 grafted mice for long-term with BLI, and found that the grafted cells had survived stably and differentiated properly into neurons and astrocytes, even 6 months after the surgery. Consistent with the result of BLI, we did not detect any evidence of tumorigenicity by grafted hNS/PCs contrast to the result of grafted U87 glioblastoma cell line during the 6-month observation period. Furthermore, neither PCNA-/Ki67-positive proliferating cells nor significant malignant invasive features were detected histologically, suggesting that hNS/PCs were not tumorigenic. These findings support the idea that hNS/PCs may represent a safe and appropriate cell source for regenerative therapies for neurological disorders. P107*. IDENTIFICATION OF CANCER STEM CELLS IN A MOUSE MODEL OF MEDULLOBLASTOMA AND MOLECULAR COMPARISON WITH NORMAL NEURAL STEM CELLS D. Corno1, B. Cipelletti1, M. Pala2, L. Politi1, A. Bulfone2, R. Galli1; 1San Raffaele Scientific Institute, Milan, Italy, 2Bio))flag, Pula (Cagliari), Italy Medulloblastomas (MBs) are the most common brain tumors in childhood. A deeper knowledge of MB biology, including the mechanisms of tumor initiation and the identification of the cells of origin, raises the possibility to improve the treatment of this malignancy by rendering therapeutic approaches more selective and reducing side-effects of therapy. In our study we focused on the characterization of cancer stem cells (CSCs) in murine MBs. CSCs have been identified in different brain tumors, including MB, as tumor founding cells, able to sustain growth and progression of the tumor and to give rise to relapse. In our model, mice carrying heterozygous patched mutations develop spontaneously MBs, which mirror the human pathology. We isolated CSC lines from 2 different murine MBs (MB CSCs), culturing the specimens under the standard conditions (i.e., in the presence of EGF and FGF2) employed to isolate normal neural stem cells (NSCs). These MB-derived lines display several features that qualify them as CSCs, such as extensive proliferation, self-renewal, multipotency, as well as aberrant differentiation. Moreover, MB CSCs are endowed with tumor initiation ability, which was assessed through orthotopic and subcutaneous injection in mice. MB is thought to arise from cerebellar neural progenitors that undergo malignant transformation; in particular, the desmoplastic variant seems to derive from the transformed precursors of the external granule layer (EGL), whereas the classic variant appears to originate from the progenitors of the IV ventricle. To assess whether this presumptive lineage relationship can be revealed by common molecular signatures, we isolated NSCs from the EGL and the IV ventricle, using subventricular zone (SVZ) NSCs as internal control, and subjected them to gene expression profiling together with MB CSCs. Microarray-based analysis shows that each MB CSC line has a typical molecular signature. Unexpectedly, when compared with normal NSCs, both MB CSCs appear to share more molecular determinants with SVZ NSCs than with EGL-derived NSCs. Based on these preliminary findings, by exploiting the relationship existing between the biology of MB CSCs and the physiological cerebellar development, it might be possible to identify still unknown pathogenetic mechanisms and new candidate target useful to develope novel and selective treatments for MBs. This project has been funded by Mariani Foundation. P108. MALIGNANT GLIOMAS RECRUIT MESENCHYMAL STEM CELLS BY SECRETION OF SDF-1 C. Schichor, I. Krotofil, J. Tonn, R. H. Goldbrunner; Dept. Neurosurgery, Munich, Germany Objective: The aim of our study was to show whether human adult mesenchymal stem cells (hMSC) can be isolated from malignant glioma specimen, obtained from neurosurgical operations and to identify the role of stromal derived factor (SDF-1) as a contributing factor of their recruitment. Materials and Methods: Glioma specimen of different grades were included in our study. hMSCs were isolated by the use of a ficoll gradient. Isolated cells were intensively characterized by FACS-analysis as well as differentiation assays into mesenchymal lineages (fat, bone). SDF-1 was analyzed by ELISA in blood samples from glioma patients before and after administration of corticosteroids as an antiedematous therapy. SDF-1 was evaluated in the glioma tissue by qPCR. SDF-1 receptor (CXCR-4) expression of hMSC was analyzed. Results: By the use of intense FACS analysis, we found the cells isolated by our protocol to express typical surface markers of hMSCs including CXCR4, the receptor of SDF-1. Differentiation assays showed that the cells, although derived from malignant glioma tissue, exhibit differentiation potential into mesenchymal cell lines, producing fat or bone. Directed invasion of hMSC in vitro was increased in presence of a SDF-1 gradient. Malignant glioma tissue showed to overexpress SDF-1, compared to normal brain tissue, obtained from patients with epileptic surgery. Serum-SDF-1 levels were elevated in patients with gliomas compared to healthy volunteers. Conclusion: Glioma tissue contains a progenitor cell type, resembling mesenchymal stem cell (hMSC) characteristics. This indicates active recruitment of these cells from the circulation by gliomas. As a possible mechanism for recruitment of hMSCs from bone marrow we identified the SDF-1/CXCR4 system. P109. CHARACTERIZATION OF CANCER STEM CELLS IN GLIOMA AND OTHER SOLID TUMOR ANIMAL MODELS C. D. Duntsch, V. K. Kukekov, T. A. Ignatova; Neurosurgery, Univ of Tennessee, Memphis, TN, United States Introduction: Over the last few years, a new component of cancer biology known as cancer stem cell (CSC) biology has emerged. This field suggests the existence of a rare cell subpopulation of stem-like cancer cells within the primary cancer cell population that is important for many important aspects of cancer cell biology. Methods: We have studied cancer cell lines from breast, bone, and brain for evidence of cancer stem cells. Using a selection of cancer stem cells via novel and previously established markers in combination with novel CSC culture techniques, we have successfully created highly enriched CSC populations from these cell lines. We have studied the cellular and molecular properties of cancer stem cell enriched populations in direct comparison to cancer stem cell depleted populations in various in vitro cell assays, chemotherapy cytoxicity studies, and animal models of cancer. Results: We have found that cancer stem cells directly or indirectly influence many major biological components of cancer biology. Further, we have demonstrated that although the majority of cancer cells (non-stem cancer cells) are sensitive to many standard of care chemotherapeutics, cancer stem cells are consistently resistant to these therapies. Finally, we have demonstrated that CSCs are important for tumorigenic and metastatic events. Conclusion: These studies indicate that a better understanding of the in vitro and in vivo biology of CSCs derived from solid tumors is necessary and should lead to new therapeutic strategies and new targets for cancer therapy. P110. NEURAL STEM CELLS IN THE COMBAT AGAINST BRAIN TUMORS: NEURAL STEM CELLS INDUCE APOPTOSIS IN GL261 GLIOBLASTOMA CELLS A. A. E. van der Meulen1,2, P. Gao1, V. Kakkar1, J. F. Reijnhoudt1, K. P. H. Biber1, H. W. G. M. Boddeke1, J. J. A. Mooij2; 1Department of Medical Physiology, University Medical Center Groningen, Groningen, The Netherlands, 2Department of Neurosurgery, University Medical Center Groningen, Groningen, The Netherlands The dismal prognosis for patients with glioblastoma multiforme asks for new treatment modalities that circumvent the problems of the blood-brain barrier, the heterogeneity of the tumor cells, and their extensive infiltrative nature. It has been shown that neural stem cells (NSCs) can migrate toward an intracerebral tumor in vivo and have the capacity to track infiltrating tumor cells. These characteristics make NSCs promising delivery vehicles in the therapy of brain tumors. Several publications indicate that NSCs might not only serve as “magic bullets” that can be loaded with tumor killing agents, they seem to have the intrinsic capacity to restrain tumor growth. We have investigated the effects of NSC conditioned media on tumor growth in vitro by performing cell viability assays of GL261 glioblastoma tumor cells with adult mouse NSC conditioned growth medium. We observed that NSC conditioned media clearly diminished the growth of glioblastoma tumor cells in vitro. When conditioned media is boiled, it loses its growth inhibitory effect. These results indicate that NSCs produce and release a heat sensitive substance (protein) which inhibits the growth of glioblastoma tumor cells. NSC conditioned media not only has growth inhibitory capacities, but even has the capacity to induce apoptosis in GL261 glioblastoma cells. Flow cytometry experiments for Annexin V and immunocytochemistry data for cleaved Caspase 3 show that GL261 cells treated with NSC conditioned media become Annexin V and cleaved Caspase 3 positive, unlike GL261 cells in normal growth media. Aim of future experiments will be to identify the protein responsible for the growth inhibitory and apoptosis inducing effects on GL261 tumor cells. P111*. EGFR EXPRESSION IDENTIFIES DISTINCT POPULATIONS OF GLIOBLASTOMA MULTIFORME CANCER STEM CELLS WITH DIFFERENT TUMORIGENIC POTENTIAL S. Mazzoleni, L. Politi, M. De Palma, R. Galli; San Raffaele Scientific Institute, Milan, Italy The most accepted theory of tumorigenesis states that only a subset of cells, i.e., the cancer stem cells (CSCs), shows the typical stem cells properties and that only this minority of cells is able to sustain tumor formation. However, different research groups have provided evidence that, in murine tumor models of leukemias and lymphomas, different subpopulations of tumor-initiating CSCs do exist and that they represent, indeed, the majority of the tumor cells. Here we demonstrate that it is possible to identify different subpopulations of CSCs on the basis of EGFR expression in glioblastoma multiforme (GBM)-derived CSC lines and, most importantly, in GBM patient tumor tissue specimens. These subpopulations of CSCs are all characterized by long-term proliferation, self-renewal, multipotency and tumor initiating capacity. This last characteristic, that is the most important to define a cell as a bona fide CSC, expresses itself differently on the basis of EGFR expression. When isolated either from patient tumor specimens or from established CSC lines and transplanted in nude mice, the cells expressing the highest level of this receptor form tumors faster than the tumor cells characterized by low or negative levels of the same protein. By analyzing tissue samples by flow cytometry, we found that the GBM tumor cells positive for the most discussed stem cell marker, the AC133, are a subpopulation contained in the EGFRpos fraction. Interestingly, the EGFRneg CSC fraction, which we demonstrated being endowed with tumorigenic capacity, is also AC133neg, thus contrasting with previous reports claiming that AC133neg cells are not tumorigenic. Interestingly, by subjecting the experimental tumors, derived from the CSCs expressing different level of EGFR, to molecular analysis, we observed that they are different both in terms of the expression of proteins belonging to the EGF receptor family and for the activation of EGFR-dependent molecular pathways. All these observations suggest that tumors are really made of different subpopulations of CSCs, each of which defined by peculiar functional and molecular characteristics. Thus, it is very important to fully understand their biology, because only through a deep comprehension of the interactions between these different types of CSCs and through a good knowledge of the alternative molecular pathways that sustains tumor growth and formation, we may plan appropriate therapeutic strategies to eradicate the GBM. P112. PROTEOMIC ANALYSIS OF MALIGNANT GLIOMA TISSUE FOLLOWING TREATMENT WITH THE RECEPTOR TYROSINE KINASE INHIBITOR ZD6474 C. Wibom1, M. Sandström2, R. Henriksson3, M. Johansson2, H. Antti4, T. Bergenheim5; 1Dept of Neurosurgery/Oncology, Umeå, Sweden, 2Dept of Oncology, Umeå, Sweden, 3Dept of Oncology / Astra Zeneca, Umeå, Sweden, 4Dept of Chemistry, Umeå, Sweden, 5Dept of Neurosurgery, Umeå, Sweden Introduction: The prognosis of glioblastoma is, despite aggressive treatment, still poor. We urgently need a better understanding of the tumor biology and the biological effects of treatment. We also need markers to assess and facilitate the improvement of existing treatment modalities as well as help develop new ones. The novel receptor tyrosine kinase inhibitor, ZD6474, has been shown to inhibit tumor growth in a rat glioma model. The mechanism of action is partly by targeting the VEGF and EGF signaling pathways. In this study we investigate the protein expression in rat brain tumor tissue following treatment with ZD6474. Methods: The BT4C-rat glioma model was used for this study. Tumor cells were stereotactically implanted into the brain of BD IX rats. 23 rats were divided into four groups. Two groups received oral treatment with ZD6474, once daily, from day 5 until day 7 or 15 after implantation, respectively. Two groups served as controls. The protein expression in brain tumor tissue from each animal was analyzed by surface enhanced laser desorption/ionization–time of flight–mass spectrometry (SELDI-TOF-MS). The data were statistically analyzed utilizing multivariate methods such as principal components analysis (PCA) and orthogonal projection to latent structures discriminant analysis (OPLS-DA). Results: ZD 6474 caused a significant inhibition of the tumor growth. Analysis of protein spectra in the tumor tissue demonstrated systematic differences in the pattern of protein expression between treated and untreated animals in both groups. We believe that analyses of protein spectra may be an interesting option for assessing biological effects induced in glioma tumor tissue by cytotoxic drugs and maybe also a method to find therapeutical markers. P113. ENHANCING THE UTILITY OF PROTEOMICS IN GLIOMA RESEARCH R. F. Deighton, J. McCulloch, I. R. Whittle; The University of Edinburgh, Edinburgh, United Kingdom Proteomics is increasingly being used to characterize human gliomas. The technology (2D electrophoresis and mass spectrometry) is powerful and allows large-scale quantitative analysis of proteins present in glioma. Furthermore, differences in posttranslational modifications important for function can be detected. Variation in design, analysis, and statistics of previous proteomic studies has meant, however, that no clear understanding of glioma biology has yet emerged. Publications rarely extend beyond a list of proteins. The aim of this study was to provide a coherent strategy to go beyond a list of differentially regulated proteins and strengthen interpretation of proteomic data in glioma research. Three main lines of investigation have been taken: [1] advanced statistics have been used to examine protein expression variability between glioma and control specimens and heterogeneity within individual tumor subtypes; [2] arithmetic cluster analysis has been performed to examine correlations between proteins that are differentially expressed; and [3] functional clustering has been employed using bioinformatics software to investigate if differentially expressed proteins modulate common biological pathways. Our results from intraoperative samples show that 48 proteins are significantly altered in glioblastoma multiforme, 26 are altered in astrocytomas, and 52 are altered in oligodendrogliomas using simple statistics. Principal component analysis demonstrates that protein variance is spread in tumor samples (of all tumor subtypes) between different patients compared to controls and that within-individual variance is similar to between-individual variance. Multiple subgroups of proteins appear to correlate in arithmetic cluster analysis and might be coregulated. Caution must be exercised however, not to introduce inadvertent bias through discriminant analysis of large proteomic data sets. Parallel functional clustering analysis provides insight into biological systems that may be perturbed. Together these stategies may allow us to capitalize on the power of proteomic technology and offer the promise of enhanced understanding of glioma pathophysiology. P114*. MUTATIONAL PROFILING OF THE GLIOBLASTOMA MULTIFORME KINOME F. E. Bleeker1,2, S. Lamba1, C. Zanon1, D. Troost3, T. J. Hulsebos3, W. P. Vandertop2, S. Leenstra4,5, A. A. Van Tilborg5, A. Bardelli1,6; 1IRCC, Candiolo, Italy, 2Neurosurgical Center Amsterdam, Amsterdam, The Netherlands, 3Academic Medical Center, Amsterdam, The Netherlands, 4St. Elisabeth Ziekenhuis Tilburg, Tilburg, The Netherlands, 5Erasmus Medical Center, Rotterdam, The Netherlands, 6FIRC Institute of Molecular Oncology, Milan, Italy Glioblastoma multiforme (GBM) is a highly malignant brain tumor for which no cure is available. To identify new therapeutic targets we performed an extensive mutation analysis of the GBM kinome. By database and literature mining we identified 76 kinases that have been found to be mutated at least twice in cancer before and selected 35 for mutation analysis. In addition, we included PTEN, TP53, and NRAS, genes that have been found mutated at considerable frequency in GBM. In total, we sequenced 199 exons belonging to 38 genes for mutations in 119 GBM tumor samples and 16 GBM cell lines. We have found at least one somatic mutation in 74 out of 119 tumor samples (62%). In all cell lines at least one mutation in TP53 or PTEN was found. In total, we identified 120 somatic mutations in 9.3 Mb of coding DNA. This mutation rate is higher than the expected “passenger” rate (p<1×10–15), indicating that most of these mutations probably represent “driver” mutations. Somatic mutations wer e found in TP53 (51), PTEN (41), PIK3CA (12), EGFR (7, only kinase domain), BRAF (3), EPHA3 (2), NRAS (1), TGFRB2 (1), FLT3 (1), and RPS6KC1 (1). We describe 30 novel somatic mutations in GBM that have not been previously characterized. PIK3CA and PTEN were mutated in a mutual exclusive manner (p<0.05). Interestingly, five out of 12 mutations in PIK3CA were located in exon 1, significant more than in the hotspot regions exon 9 and 20 (p<0.05). Three of these five mutations were not reported before, and one of these mutations was present in two independent tumors. This indicates that PIK3CA has a different mutation distribution in GBM than in other human solid tumors (p<0.05). No mutations were found in the downstream kinase AKT1 in any sample. Analyzing the mutation ratio of the kinome excluding the results of TP53, PTEN and PIK3CA, we found a frequency of 2.5 mutations per Mb tumor DNA, higher than reported previously in GBMs. No difference in number of mutated samples and mutation ratio between untreated samples and samples treated with temozolomide was found. Most mutations were found in genes belonging to the PI3K-AKT pathway; at least in 45% of GBMs there is a mutational activation of the pathway, therefore the PI3K-AKT pathway represents an interesting therapeutic target for GBMs. P116*. COMPARATIVE STUDY OF GENE EXPRESSION AND PROTEIN EXPRESSION PROFILING IN GLIOMAS O. Persson1, U. Brynnel2, F. Levander2, B. Widegren1, M. Krogh3, L. G. Salford1; 1Dept. of Neurosurgery, Lund University, Lund, Sweden, 2Dept. of Protein Technology, Lund University, Lund, Sweden, 3Dept. of Theoretical Physics, Lund University, Lund, Sweden Gliomas are highly malignant tumors with a very poor prognosis even with state of the art treatment. Some experimental therapies using, e.g., immunotherapy, monoclonal antibodies, or stem cell therapy show some promising results. However, many of these approaches seem to be beneficial only in a portion of the patients, and careful categorization of the tumorigenic lesions is therefore called upon to efficiently be able to individualize therapy. Careful characterization of these lesions is also an important step toward novel therapeutic approaches. Both microarray gene expression profiling and proteomics have earlier been shown to efficiently categorize tumors according to histopathologic grade and to identify novel potential tumor antigens. We have here undertaken both microarray gene expression profiling and proteomic profiling in, to a large extent, an identical set of tumor tissue specimens. We find that both approaches can separate tumors according to grade, although the performance was higher for the microarray experiment, likely due to the superior number of reporters. The large number of identified reporters also made it possible to select for proteins with specific attributes, e.g., plasma membrane association, and we identified both some well known but also some novel potential tumor antigens. The proteomic assay in turn shows strengths in being able to identify multiple isoforms of a protein, acknowledging different splicing variants and post-translational modifications. We found indications of a shift in which GFAP fragments are expressed in different tumor grades. This finding is interesting in light of other recent studies showing GFAP to be a potential serum marker for high-grade gliomas. Interestingly, both the microarray and the proteomics approach identified several proteins related to the Raf/MEK/Erk and the PI3K pathways to be affected in gliomas. In a paired comparison of the mRNA levels to the protein levels, however, we often found the correlation to be weak. The reasons for this could be multiple, but anyhow it emphasizes the importance of careful characterization on the protein level, since important tumorigenic proteins or potential antigens might be missed if post-translational modifications and regulations are disregarded. P117*. ANALYSIS OF GATA-6 EXPRESSION IN PROGRESSION FROM LOW GRADE GLIOMA TO SECONDARY GLIOBLASTOMA G. Carrabba1, S. Agnithori2, D. Munoz2, S. Ehsani3, D. Mukhopadhyay1, S. Croul3, A. Guha1,2; 1Neurosurgery, Western Hospital, University of Toronto, Toronto, ON, Canada, 2Arthur & Sonia Labatts Brain Tumor Center, HSCRI, University of Toronto, Toronto, ON, Canada, 3Pathology-Neuropathology, Western Hospital, University of Toronto, Toronto, ON, Canada GATA-6 is a transcription factor, which was recently identified as an astrocytoma tumor suppressor gene, using random mutagenesis strategies on transgenic mouse glioma models. GATA-6 is widely expressed in normal glial cells and its loss was associated to astrocytoma progression in the mouse. In a cohort of human glioblastomas (GBMs), ∼85% demonstrated loss of GATA-6 expression, while only ∼10% of low grade glioma (LGG) specimens did not express GATA-6, reinforcing the mouse model data. In this present study, we analyzed specimens from a group of patients who had an initial pathological diagnosis of LGG and a second surgery when the tumor progressed to a secondary GBM. We recruited 32 patients, 16 males and 16 females with ages ranging between 18 and 67 (median 39). The interval between surgeries ranged between 0 and 11 years (mean 3.34 years). The histopathological diagnosis was reviewed by a single neuropathologist (SC). Of the 32 LGG specimens, 8 were classified as oligodendrogliomas (O), 18 as astrocytomas (A), and 6 as mixed oligo-astrocytomas (O-A). Paraffin sections from the LGGs and secondary GBMs of the same patient were fixed on the same slide, to avoid any variation between immunohistochemical staining protocols. A rabbit GATA-6 polyclonal antibody (1:100; Abcam), followed by a secondary biotinylated goat antirabbit antibody (Vector Laboratories, Burlingame, CA) and the avidin-biotin-peroxidase complex method were used for detection with diaminobenzidine tetrachloride (Vector Laboratories). The results of the GATA-6 expression profile in patients with a documented progression from LGG to GBM will be presented. Subgroups analysis will include differences between the original subtype of LGG: O, A, O-A. In addition, the correlation of GATA-6 expression profile with other relevant clinical parameters such as age, sex, interval time between surgeries, and overall survival will be analyzed. This study extends our observation on GATA-6, which stemmed from mouse models to patients with malignant progression of their gliomas, as to the role of this novel tumor suppressor in gliomagenesis. P118*. SIMILARITIES AND DEVIATIONS IN MICRORNA SIGNATURE OF GLIAL TUMORS, EMBRYONIC STEM CELLS, AND NEURONAL PROGENITOR CELLS I. Lavon1, D. Zrihan1, M. A. Cohen1, B. Reubinoff1, O. Einstein1, T. Ben-Hur1, Y. Smith2, T. Siegal1; 1Hadassah Hebrew University Hospital, Jerusalem, Israel, 2Hebrew University, Jerusalem, Israel Background: microRNA (miRNA) is a family of small nucleotides that regulates gene expression. The miRNA family contains 500–600 members in humans and by estimates it may inhibit the expression of hundreds of different gene products. Therefore, the miRNA family has the potential to regulate almost all of the genetic and physiologic pathways of the cell, including development, metabolism, proliferation, differentiation, and programmed cell death. Impaired miRNA expression is related to different diseases, including malignancy, which is characterized by uncontrolled self-renewal and abnormal differentiation. Stem cells have a pre-existing capacity for self-renewal and “unlimited” proliferative potential and therefore they are considered as a possible source of malignancy. Our goal was to address the issue, whether stem cells are the source of cancer cells, or whether cancer cells have acquired “stem-like” properties. Objective: to compare the profile of miRNA expression in glial tumors, embryonic stem cells, neural progenitor cells, and normal adult brain in order to enhance the understanding of glioma genesis. Methods: Expression of 186 human miRNAs was evaluated in tissue RNA samples of 7 glial tumors, embryonic stem cells, neuronal progenitor cells, and commercially available normal adult brain, using stem-loop primers for reverse transcription followed by real-time PCR. Results: In gliomas, 58 miRNAs out of the 186 tested demonstrated distinct expression when compared with normal adult brain. Strikingly, a similar expression pattern of these 58 miRNAs was present in neuronal progenitor cells or/and embryonic stem cells. However, in stem cells 15 other miRNAs had a unique signature not observed in normal brain or in gliomas. No significant difference was noted between miRNA expression profile of low and high-grade gliomas. Conclusions: Substantial similarity was found between miRNA signature of gliomas and neuronal progenitor cells and/or embryonic stem cells. Additional studies are needed to determine whether the origin of gliomas is from adult stem cells or from de-differentiated glial cells that acquired stemness. Careful study of the 15 miRNAs that differed between stem cells and gliomas may enhance our understanding of gliomagenesis. Furthermore, our findings that miRNA signature of low and high-grade gliomas is similar may imply that low-grade gliomas already carry the potential to become highly aggressive tumors. P119. EXPRESSION OF THE CELL ADHESION AND GUIDANCE PROTEIN ATTRACTIN IN GLIOMAS CORRELATES WITH TUMOR GRADE N. Thon1, H. Leske1, F. Restle1, S. Grau1, A. Baiker2, J. Tonn1, R. Goldbrunner1; 1Department of Neurosurgery, Munich, Germany, 2Max von Pettenkofer Institute, Munich, Germany Objective: Attractin is a member of the CUP family of cell adhesion molecules. Attractin contains an EGF domain primarily responsible for receptor-ligand and protein-protein interactions. Loss-of-functions mutations of attractin result in age-dependent progressive neurodegeneration. Recently, it has been shown that the secreted isoform of attractin is elevated in the CSF of patients with malignant astrocytomas. The purpose of this study was to analyze the expression pattern of membrane bound attractin in gliomas of different grades. Methods: The expression of transmembrane attractin has been investigated in primary tumor probes harvested from own surgical files using immunohistochemestry, Western blot, and RT-PCR analysis. Identification of the attractin expressing cell population has been addressed by double immunolabeling technique in primary glioblastoma cell cultures. Result: Using immunohistochemical staining techniques attractin expression has been found to correlate strongly with glioma grading. As a control attractin expression was also detectable at low levels in normal brain tissues being predominantly expressed by beta-III-tubulin+ neuronal cells. Protein expression has been confirmed by Western blot analysis verifying the correlation of membrane bound attractin expression with tumor grade. In primary glioblastoma cell cultures attractin co-localized with the astroglial and tumor marker GFAP as well as with microglial (CD11c), macrophage and monocyte surface markers (CD14, CD68). Discussion: Membrane bound attractin has been found to be secreted by activated human T-lymphocytes and macrophages and modulate systemic immune cell interactions. So far, little is known about attractin expression in cancer. Whereas attractin can be found at low levels in neurons of the CNS and is absent in the CSF of normal controls secreted attractin in the CSF has been found to correlate with glioma malignancy. Here we show that membrane-bound attractin is also highly upregulated in glioma cells correlating with tumor grade. Besides co-expression with the glial and tumor marker GFAP attractin has been also strongly co-localized with intratumoral CD11c+ microglial and CD14+/CD68+ macrophages. Since transmembrane attractin plays a functional role in inflammation, anti-apoptotic processes and the interaction of cells with their extracellular environment upregulation of attractin in malignant gliomas might support the invasion of immune cells, play a role in the tumor cell response to cytokines, e.g., by the EGF-like domain as well as propagate adhesion, migration, and proliferation of tumor cells. Further investigations are needed to analyze the functional role of attractin in glioblastomas as a possible new target in glioblastoma therapy. P120. DO EXPRESSIONS OF OLIG2, PTEN AND DMBT1 GENES PLAY A ROLE IN HIGH-GRADE GLIOMAS PROGRESSION? C. Biray Avci1, N. Oktar2, T. Dalbasti2, S. Yilmaz1, Y. Dodurga1, Z. O. Dogan1, S. Numanoglu1, T. Akalın3, C. Gunduz1; 1Ege University Medical Faculty Medical Biology Department, Izmir, Turkey, 2Ege University Medical Faculty Neurosurgery Department, Izmir, Turkey, 3Ege University Medical Faculty Pathology Department, Izmir, Turkey High-grade gliomas are the most common primary brain tumors and associated with poor survival. Deleted in malignant brain tumor-1 (DMBT-1), is a candidate tumor suppressor gene that is located at chromosome 10q 25.3–26.1. In brain, lung, and gastrointestinal tumors, homozygous deletions and lack of mRNA expression DMBT1 are frequently observed. Phosphatase and tensin homology deleted on chromosome 10 (PTEN) expression potently suppressed the growth and tumorigenicity of human glioblastoma cells. Expression of PTEN in cancer cells devoid of a functional gene product has been shown to inhibit cellular growth and the tumorigenic capabilities of cells. Genetic alterations occurs at high frequency in a variety of human tumors is loss of heterozygosity (LOH) at 10q23. Oncogenes are generally mutated form of protooncogenes that cause the transformation of normal cells into a cancerous tumor cells. They stimulate cell growth and over-expression of these genes cause growing out of control. Human oligodendrocyte lineage transcription factors 2 (OLIG2) gene is an oncogene that is expressed strongly in oligodendroglioma. Neoplastic cells of oligodendroglioma resemble oligodendrocytes or their progenitor cells and may derive from cells of this lineage. In this study we aimed to identify the roles of these genes and correlation between their expression profiles in malignant disease progression. Human brain tumor samples were obtained from patients who underwent primary therapeutic subtotal or total tumor resection performed under surgical operation. All cases signed a written informed constant statement approved by local ethics committee. Explant cell cultures were performed from brain tumor tissues of 21 (9 females, 12 males; average age 50.24±16.10) cases. Malignant lesions have been described in the medical history of all cases: GBM WHO grade IV (21 cases). Total RNA was isolated from tumor cells. RNA of the tumor samples were reverse-transcribed with oligo dT primers and quantified by real-time reverse transcription polymerase chain reaction performed with the LightCycler instrument. U87MG glioblastoma cell line was used as positive control. Gene expression levels higher than U87MG gene expression were accepted as positive. The mean relative ratios of DMBT1, PTEN, and OLIG2 genes were found; 0.546, 203.691, and 0.661, respectively. When we compare the gene expression levels with U87-MG cells, we found that DMBT1 gene expression was significantly decreased (p<0.0001). Similar repression was found in PTEN gene expression (p=0.002). Due to the evaluation of OLIG2 gene expression results in cases, we found elevated gene expression levels but there was no significance in positive cases. In conclusion, the expression changes in DMBT1, PTEN, and OLIG2 genes give promise to build pivotal biomarkers and smart and effective drug combinations in molecular targeted treatments of malignant gliomas. P121. ANTITUMOR ACTIVITY OF PARTHENOLIDE AGAINST HUMAN GLIOMA CELL LINES H. Nakabayashi, K. C. Park, K. Shimizu; Kochi University, Nankoku, Japan Parthenolide is a major sesquiterpene lactone derived from feverfew (Tanacetum parthenium) with known anti-inflammatory activity. Moreover, the anticancer potential of this compound was suggested. In this study, we determined the effect of parthenolide on three human glioma cell lines: U87MG, T98G, SNB19, and human umbilical vein endothelial cells (HUVEC) in vitro. The cytotoxicity of parthenolide was determined by the MTT assay. Parthenolide inhibited proliferation of all three types of glioma cells. The anti-invasive effect of parthenolide was analyzed by the Matrigel invasion assay. The invasion of glioma cells was suppressed by parthenolide. An in vitro angiogenesis assay was also performed using the double chamber co-culture system. Parthenolide had a suppressive effect on the angiogenesis that was induced by glioma cells. The results revealed that parthenolide has antitumor effects against human glioma cells. P122. GLIOMA CELL-MEDIATED UPREGULATION OF CD62E ON ENDOTHELIAL CELLS CONTRIBUTES TO GLIOMA TROPISM OF ADULT HEMATOPOIETIC PROGENITOR CELLS G. Tabatabai1, R. Moehle2, M. Mittelbronn3, M. Weller4, W. Wick5; 1Department of General Neurology, Tuebingen, Germany, 2Department of Internal Medicine, Hematology, Tuebingen, Germany, 3Institute for Brain Researach, Tuebingen, Germany, 4Department of Neurology, Zurich, Switzerland, 5Department of Neurooncology, Heidelberg, Germany Experimental gliomas attract hematopoietic progenitor cells (HPC) in vivo. This glioma tropism is further enhanced by irradiation or hypoxic preconditioning of the glioma cells. Here, we investigated the role of adhesive interactions for the preferential accumulation of HPC within the glioma tissue by characterization of the HPC-interactions with endothelial cells in vitro. Exposure of human cerebral endothelial cells (SV-HCEC) to supernatants of LNT-229 glioma cells induced the expression of E-selectin (CD62E). CD62E expression was also induced when the glioma cells had been exposed to irradiation or hypoxia as well as by irradiation of the SV-HCEC at 8 Gy or exposure to hypoxia. Transendothelial migration assays through an SV-HCEC layer showed enhanced HPC migration after CD62E induction. This transendothelial migration was impaired by addition of neutralizing CD62E antibodies. Tissue microarrays of 120 human glioblastoma and 60 normal brain tissue samples revealed a CD62E expression on endothelial cells of glioblastoma vessels. Glioma supernatant-induced CD62E expression on endothelial cells in vitro required TGF-β signaling in glioma cells as well as vascular endothelial growth factor (VEGF-A)-VEGF-receptor 2 (VEGF-R2) signaling in endothelial cells. Finally, we observed a nuclear factor kappa B (NFκB)-dependent activation of the CD62E promoter peaking at 12 h after VEGF-R2 activation by glioma-derived VEGF-A. In summary, we describe a glioma cell-induced CD62E expression on endothelial cells that might contribute to the glioma tropism of HPC. P123. MODULATION OF TGF-B ACTIVATION IN GLIOMAS BY LTBP1 D. Gramatzki1, M. Weller2, D. Capper3, M. Mittelbronn3, W. Wick4, I. Tritschler1; 1Laboratory of Molecular Neurooncology, Department of General Neurology, Hertie Institute for Clinical Brain Research, Tuebingen, Germany, 2Department of Neurology, University Hospital of Zurich, Zurich, Switzerland, 3Institute of Neuropathology, University Hospital of Zurich, Zurich, Switzerland, 4Department of Neurooncology, University of Heidelberg, Heidelberg, Germany High biological activity of transforming growth factor (TGF)-β may mediate tumor cell invasiveness and immunosuppression in malignant gliomas. Accordingly, this cytokine has become a novel target in the experimental treatment of these tumors. Latent TGF-β binding protein 1 (LTBP1), mainly located in the extracellular matrix (ECM), is covalently bound to latent TGF-β and regulates its function. To explore LTBP1 in diffuse human astrocytomas, we performed immunohistochemistry for LTBP1 expression in neoplasms of WHO grades II–IV. Low LTBP1 levels were seen in normal brain and WHO grade II astrocytomas tumors, whereas all other grades demonstrated an increase in LTBP1 protein levels. LTBP1 expression among human glioma cell lines was variable. The functional role of LTBP1 was studied by plasmid-mediated overexpression of LTBP1 in the glioma cell line LNT-229, which expresses low levels of LTBP1. LTBP1 overexpression resulted in increased TGF-β bioactivity in a luciferase-based TGF-β bioactivity assay for both mature and total TGF-β. Accordingly, we observed an increase in Smad2 phosphorylation as an intracellular marker of enhanced TGF-β bioavailability. A transient knockdown of LTBP1 in the glioma cell line LN-308 significantly reduced Smad2 phosphorylation. These data define a role for LTBP1 in the control of TGF-β bioavailability in malignant gliomas. P124. DEVELOPMENT OF A MURINE MODEL OF ANTILEUKEMIC THERAPY INDUCED BRAIN TUMORS T. Jones1,2, C. Johns1, J. Barnes1, C. Duntsch1; 1University of Tennessee Health Science Center, Memphis, TN, United States, 2St. Jude Children's Research Hospital, Memphis, TN, United States Introduction: Acute lymphoblastic leukemia (ALL) is the most common childhood cancer. One consequence of anti-leukemic therapy is the risk of secondary cancers; and the most common and devastating are malignant brain tumors. Antimetabolites (i.e., methotrexate, thiopurines) are the backbone of ALL therapy and are commonly used in combination with ionizing irradiation in patients classified as high-risk for relapse. An unusually high incidence of secondary brain tumors was observed in a subset of patients enrolled on an ALL total therapy protocol (TXII) at St. Jude Children's Research Hospital. Interestingly, a significant proportion of the affected patients were deficient for thiopurine methyltransferase (TPMT), an enzyme important for the deactivation of thiopurine drugs. The 8-year cumulative incidence of brain tumor development in patients with dysfunctional versus wild-type TPMT was 42.9% versus 8.3%, respectively. Using a TPMT knockout mouse strain treated with antimetabolites and cranially directed irradiation, the importance of TPMT in brain tumor development can be ascertained. Methods: We chose antimetabolite doses that were comparable to doses received by children treated for ALL. Radiation doses were based on clinical doses and the high radiation tolerability of mice. To determine the maximum tolerated doses of cranial irradiation and antimetabolites (methotrexate and thioguanine), we irradiated TPMT mice with 48 Gy or 72 Gy (divided in two doses/week for 6 weeks) or treated with methotrexate (1 mg/kg/wk) plus thioguanine (0.1–0.75 mg/kg/dy) for 6 weeks. Mice showing signs of sickness were sacrificed and brain pathology studies were performed. Results: Both doses of radiation were well tolerated. However, thioguanine was only tolerable at very low doses. Interestingly, preliminary pathology data suggest that mice treated with antimetabolite therapy alone may have more extensive brain injury than those treated with cranial irradiation alone. Conclusion: These studies have identified the maximum tolerated doses of radiation and antimetabolites that can be used in combination to study the role of TPMT and antileukemic therapy in brain tumor development. Additionally, we found that TPMT mice may suffer extensive brain injury when treated with antimetabolites; however, more studies will need to be performed to validate this finding. P125. ANTICANCER ACTIVITY OF SELECTED SYNTHETIC CHALCONE ANALOGUES AGAINST BEN-MEN-1 HUMAN BENIGN MENINGIOMA CELL LINE M. Sarissky1, M. Pilatova1, P. Perjesi2, J. Mojzis1, I. Sulla3; 1Dept of Pharmacology, Faculty of Medicine, P.J. Safarik University, Kosice, Slovakia, 2Dept of Medical Chemistry, University Medical School of Pecs, Pecs, Hungary, 3Dept of Neurosurgery, Faculty of Medicine, P.J. Safarik University, Kosice, Slovakia Introduction: Ben-Men-1 is a human benign meningioma cell line established from meningothelial meningioma cells immortalized by retroviral transduction of hTERT. The cells display monosomy 22 typical for WHO grade I tumors. Despite their benign nature, around 20–25% of these tumors recur within 10 years after initial therapy. Here, we studied potential anti-meningioma effects of selected synthetic analogues of chalcones, intermediates in the biosynthesis of flavonoids with relatively well-characterized anticancer properties. The tested agents included Q-510 (E-2-[4′-methoxybenzylidene]-1-benzosuberone), Q-705 (E-2-[2',4'-dimethoxybenzylidene]-1-tetralone) and Q-766 (E-2-[4′-hydroxybenzylidene]-1-benzosuberone). Methods: Cytotoxic effects of Q-510, Q-705, and Q-766 on Ben-Men-1 cells were assessed using the colorimetric MTT assay. Apoptotic activities of the tested agents were analyzed by flow cytometry using Annexin V/PI staining and DNA cell cycle analysis. Results: Of the tested chalcone analogues, Q-510 displayed a significant cytotoxic effect on Ben-Men-1 cells in a concentration-dependent manner with an EC50 of 2.682 ± 1.999 μM. At 1 microM, Q-510 induced apoptosis in Ben-Men-1 cells increasing significantly the percentage of both apoptotic (AnnexinV+/PI-) and necrotic (AnnexinV+/PI+) cells from 1.0 ± 0.4% to 7.6 ± 2.6% and from 2.5 ± 0.9% to 4.3 ± 0.5% in untreated vs. treated cells, respectively. A similar increase was also observed in the percentage of sub-G0/G1 cells: from 2.6 ± 3.4% in untreated cells to 21.3 ± 9.7% in cells treated with 1 microM Q-510 for 72 hours. For Q-705 and Q-766, no cytotoxic or apoptotic activities against meningioma cells were observed. Conclusion: Q-510, a synthetic chalcone analogue, possesses a significant anti-meningioma activity at micromolar concentrations. Further studies are necessary to elucidate its mechanism of action as well as its potential utility in the treatment of recurring benign or anaplastic/malignant meningiomas. This work was supported by the Slovak Research and Development Agency under the contract No. APVT-20-032504. P126. AVB3 AND AVB5 INTEGRINS CONTROL HYPOXIA THROUGH FAK AND RHOB IN GLIOMA E. Cohen-Jonathan-Moyal1, N. Skuli1, S. Monferran1, C. Delmas1, G. Favre1, J. Bonnet2, C. Toulas1; 1Institut Claudius Regaud-INSERMU563, Toulouse, France, 2Institut Claudius Regaud, Toulouse, France The aggressiveness of the glioblastoma as well as their resistance to anti-cancer therapies is largely due to the presence of large zones of hypoxia in these tumors. We investigate here the role of adhesion pathway through avb3 and avb5 integrins in the control of hypoxia in U87 and SF763 glioblastoma models. Incubating glioma cells in hypoxic conditions increased the recruitment of integrins to the cellular membrane and activated FAK. Silencing avb3 or avb5 integrins in avb3integrin-expressing U87 cells and in avb5 integrin-expressing SF763 cells decreased the level of the hypoxia-inducible factor HIF-1a in hypoxic conditions. This integrin-dependent regulation of HIF was mediated by FAK, which in turn activated the small GTPase RhoB. Silencing avb3 integrin/FAK pathways in U87 xenografts led to an oxygenation of the tumor associated with a normalization of the vasculature. We identify here a new biological pathway of hypoxia regulation in glioblastoma cells activated from the membrane at least by avb3 or avb5 integrins. Taken together, our results strongly suggest that targeting this integrins-dependent hypoxia pathway may be of great interest to improve the efficiency of anti-cancer therapies by reducing hypoxia in these tumors. P127. THE SODIUM PUMP Α1 SUBUNIT AS A POTENTIAL TARGET TO COMBAT APOPTOSIS-RESISTANT GLIOBLASTOMAS F. Lefranc1, T. Mijatovic2, R. Kiss1; 1Free University of Belgium, Brussels, Belgium, 2Unibioscreen, SA, Brussels, Belgium Malignant gliomas are associated with dismal prognoses because they diffusely infiltrate the brain parenchyma, therefore rendering total surgical resection of all tumor cells impossible. In addition, those migrating glioblastoma (GBM) cells that escape the most sophisticated surgical approaches are resistant to apoptosis and thus to radiotherapy and most chemotherapeutic agents. Glioma cells are “self-propelled” and are able to adjust their shape and volume rapidly as they invade the brain parenchyma. Essential to this process is the activity of chloride channels and anion transport mechanisms. The sodium pump (NaK) is another ion transporter which in addition to exchanging cations is also directly involved in the migration of cancer cells in general and of GBM cells in particular. Our data emphasize the fact that a cardenolide-mediated decrease in NaK α1 subunit activity could be used to combat apoptosis-resistant GBMs. Our preliminary studies indicate that NaK α1 subunits seem to be up-regulated in a proportion of GBMs but not in normal brain tissues. Our strategy has been to target the α1 subunit of the NaK in those GBMs that over-express this subunit with novel, potent, and selective cardenolides. The natural ligands of the NaK are the cardiotonic steroids including both cardenolides and bufadienolides. UNBS1450, an hemi-synthetic derivative of 2′-oxovorusharin, a novel cardenolide identified in Calotropis procera, displays unique structural features, making its binding affinity to NaK α subunits (including α1) 10–100 times higher than that of digoxin, digitoxin, or ouabain. UNBS1450 markedly decreases [ATP]i in glioma cells (but not in normal cells), a feature which in turn disorganizes the actin cytoskeleton and finally leads to autophagic cell death in NaK α1 over-expressing glioma cells. In conclusion, the targeting of NaK α1 subunits in GBM cells appears to impair both their proliferation and migration, even if they are resistant to apoptosis. Therefore potentially those GBM patients who do not or who no longer respond to conventional chemotherapy and whose tumors over-express NaK α1 subunits could benefit from a treatment using specific ligands with marked binding affinity for the NaK α1 subunit. P128. BASIC FIBROBLAST GROWTH FACTOR DEPENDENT EXPRESSION OF PLATELET DERIVED GROWTH FACTOR RECEPTOR-ALPHA IN GLIOMA CELLS X. Fan; The Rausing Laboratory, Lund, Sweden Glioma cells frequently express platelet derived growth factor receptor-α (PDGFR-α), and glioma-like growth can be induced in glial progenitor cells by enforced PDGFR-α signaling. However, the induction mechanisms of glioma cell PDGFR-α expression are poorly clarified. We hypothesize that glioma cell PDGFR-α expression could be niche factor dependent. PDGFR-α expressing glioma cells were cultured under low-serum conditions with combinations of various neural growth factors. Fluorescence in situ hybridization (FISH) analysis in short-term cultured cells demonstrated no amplification of PDGFR-α gene. We identified that a combination between basic fibroblast growth factor (bFGF), sonic hedgehog (SHH), and platelet derived growth factor-AA (PDGF-AA) allowed relatively long-term culture of glioma cells with maintained PDGFR-α expression. Omitting bFGF, but not SHH or PDGF-AA, resulted in rapid down-regulation of PDGFR-α expression, which coincided with diminished cell proliferation. bFGF alone was able to support PDGFR-α expression in a concentration-dependent manner. However, cultures supported by bFGF alone ceased to proliferate much earlier with senescence-associated β-Gal staining compared to the parallel bFGF, SHH and PDGF-AA supported cultures. Our data demonstrate that glioma cell PDGFR-α expression can be critically dependent on bFGF. Thus, bFGF or other members of FGF family mediated signaling can be important therapeutic target for glioma. P129. TYROSINE KINASE RECEPTOR SIGNALING IN GLIOBLASTOMA CELLS: THERAPEUTIC IMPLICATIONS O. Alexandru1, M. Carapancea2, A. Fetea1, L. Dragutescu1, J. Castro2, A. M. Georgescu3, M. L. Backlund4, A. Dricu5; 1University of Medicine and Pharmacy, Craiova, Romania, 2Cancer Center Karolinska, Stockholm, Sweden, 3Medico Science SRL, Bucharest, Romania, 4Radiumhemmet Karolinska Institute/University Hospital, Stockholm, Sweden, 5Karolinska Institute/University Hospital, Stockholm, Sweden Glioblastomas (GB) are the most aggressive intracranial tumors and remain refractory to conventional therapy. Growth factor receptors like platelet-derived growth factor receptor (PDGFR) and insulin like growth factor-1 receptor (IGF-1R) initiate a signal transduction leading to uncontrolled cell proliferation but also to cytoprotection against cell death induced by several insults, such as radiation. Cross-talk between IGF-1R and PDGFR pathways in activation of phosphatidylinositol 3-kinase (PI3-K), and extracellular signal-regulated kinase (ERK1/2) has been suggested by several studies. In this study, we analyzed the expression of PDGFR, IGF-1R, PI3-K, and ERK1/2 proteins in five primary GB cell lines (MO59J, MO59K, 8, 18, and 38). Our results demonstrated that appreciable levels of IGF-1R, PDGFR membrane kinases and PI3-K and ERK1/2 intracellular kinases could be detected in the analyzed tumor cell lines, except for a low level of PDGFR and ERK1/2 expression in MO59J cells. We also investigated the effects of the small molecule inhibitors AG1024, AG1433, LY294002, and PD98059 (toward IGF-1R, PDGFR, PI3-K, and ERK1/2 respectively) on the viability of human GB cells. In general, the small molecule inhibitors used in this study have only modest or no anti-tumor activity on GB cells and therefore their combination with other therapy modalities was analyzed. The interaction between small inhibitors and radiation was mostly additive (45%) or sub-additive (42.5%); synergistic interaction was found in five of forty (12.5%) analyzed combinations. Our results showed that GB cells are in general resistant to treatment and illustrate the difficulties in predicting the treatment response in malignant gliomas. P130. REAL TIME MONITORING OF KININ B1 RECEPTOR-MEDIATED BLOOD BRAIN BARRIER DISRUPTION IN A F98 GLIOMA RAT MODEL USING MRI J. Cote, M. Lepage, F. Gobeil, D. Fortin; Université de Sherbrooke, Sherbrooke, QC, Canada Objectives: The blood-brain barrier (BBB) prevents the passage of drugs to the central nervous system (CNS) through diffusion. Treatment of CNS neoplasia with chemotherapy is limited mostly because of delivery impediment related to this barrier and also by the natural or acquired resistance expressed by tumor cells. Multiple techniques have been studied to improve delivery across the BBB, e.g., mannitol intra-carotid infusion and focused-ultrasound. Recent evidence suggests that vascular B1 receptors (B1R) can regulate BBB permeability, including that of brain tumors. Dynamic magnetic resonance imaging (MRI) was used to monitor the selective increased of BBB induced by 3 different bradykinin agonists in F98 glioma-implanted Fischer rats: the natural B1R agonist (LDBK), a synthetic B1R agonist (NG29), and a B2R synthetic agonist (R523). Methods: Glioma cells were implanted stereotactically in the region of the right caudate nucleus in a total of 56 Fischer rats, and tumor development was allowed for 10 days. Experiments were conducted on anesthetized animals placed in a 7T animal RMN (Varian). A bolus of either Gd-DTPA (548 Da) or a larger Gd-based contrast agent (17 kDa) was injected i.v. (tail vein) with simultaneous monitoring of T1-weighted images for a period of 1h, in the purpose of determining the extent of the BBB permeabilization. Experiments were repeated 12h later, immediately following the BBB disruption procedure initiated by infusing (0.1 ml/min for 5 min) in the right external carotid artery or in the left jugular vein one of the 3 agonists: LDBK, NG29, or R523 (2.5, 10, or 50 nmol/kg). Anatomic MR images were analyzed for the presence or absence of contrast enhancement within and surrounding the tumor area, and were processed to yield quantitative contrast agent distribution volume (CADV). Since normal BBB prevents the passage of both contrast agents, the CADV reflects the volume where the BBB is leaky or has been permeabilized. Results: Our results suggest that intracarotid NG29 infusion modulates topographic uptake profiles of both contrast agents within rat glioma and brain tissue surrounding the tumor without affecting normal brain parenchyma from ipsi and contralateral hemispheres. Maximum CADV nearly doubled in the NG29-treated animals at the intermediate dose of 10 nmol/kg for both of the constrast agent. This latter effect was also observed with R523 but not with LDBK and was negated by co-infusion of excess B1R antagonist R892. Moreover, higher dose of B2 agonist R523 (50 nmol/kg) permeabilized the BBB non-selectively away from the tumor site, while all doses of B1 agonist remained selective for the tumor barrier and the brain around tumor area. Conclusion: Our results support the use of synthetic B1R agonists as selective tumor BBB permeabilizers to improve delivery of chemotherapeutics in the CNS at the tumor and peritumoral area. P131. GLUCOSE METABOLITES, GLUTAMATE, AND GLYCEROL IN MALIGNANT GLIOMA TUMORS DURING RADIOTHERAPY P. Tabatabaie1, P. Bergström2, R. Henriksson2, T. Bergenheim1; 1Institution of Neuroscience, Umeå, Sweden, 2Institution of Oncology, Umeå, Sweden Objective: The most common and aggressive primary tumors in the brain is high-grade astrocytoma. The biology of these malignant tumors is partly unknown, especially on a cellular and molecular level. A better understanding of the underlying biology of these tumors would enhance the search for and evaluation of future therapeutic options. In this study, utilizing the technique of stereotactic microdialysis, we have investigated the glucose metabolism and the levels of glutamate and glycerol as markers for neurotoxicity in malignant glioma tissue and brain adjacent to tumor (BAT) in 13 patients with high-grade astrocytomas during five days of radiotherapy. The main objective was to investigate the metabolic pattern of glucose, lactate, and pyruvate as well as the levels of glutamate and glycerol in tumor tissue during base-line conditions and to detect any changes following radiotherapy. Method: With a stereotactic technique, two microdialysis catheters were implanted in conjugation to a tissue biopsy: one in solid tumor tissue and one in brain adjacent to tumor. Postoperatively the patients were followed before and during 5 days of radiotherapy given with 2 Gy fractions. Fasting samples were analyzed daily. Results: Base-line levels of glucose and pyruvate were significantly lower in tumor compared to peri-tumoral tissue (p = 0.04 and 0.023, respectively). The lactate/pyruvate ratio was significantly higher in tumor tissue (p = 0.033). In general, the levels of lactate, glutamate, and glycerol were higher in tumor tissue, although not statistically significant. Further, we could not detect any significant changes during the five days of radiotherapy in any of the metabolites analyzed. Conclusion: Radiotherapy up to 10 Gy given in five fractions does not influence the glucose metabolism nor does it induce any acute cytotoxic effect detected with glutamate or glycerol in malignant glioma, as assessed by microdialysis. The study confirms the glycolytic properties of glucose metabolism in malignant glioma. P132. BEHAVIOUR DIFFERENCES BETWEEN PRIMARY AND SECONDARY HUMAN BRAIN CANCER: ANATOMICAL DEPENDENCY INSIDE THE TUMOR MASS F. M. Santandreu1, M. E. Couce2, M. Brell3, A. H. Gene2, J. Oliver1, P. Roca1; 1Grup de Metabolisme Energètic i Nutrició, Universitat de les Illes Balears, Spain, 2Servicio de Anatomía Patológica, Hospital Universitario Son Dureta, Spain, 3Servicio de Neurocirugía, Hospital Universitario Son Dureta, Spain Knowledge of redox status in human brain cancer is important in order to acquire a better understanding about the different patient's response developed to standard therapies even when the same histological grade is diagnosed. Oxidative stress, mitochondria-to-nucleus stress signaling and proliferation rate modulate cancer cell susceptibility to radiotherapy and chemotherapeutic agents. The aim of the present study was to characterize oxidative stress markers and mitochondrial features of human gliomas and human brain metastasis. Central and peripheral concentric regions were sampled from tumoral specimens. Only maximal surgical resections were chosen and subsequent measurements were performed with fresh tumor tissue. Nine patients undergoing surgery were included in our study (6 gliomas and 3 metastasis). There were not significant differences between primary and metastatic brain tumors in oxidative phosphorylation system, lipid peroxidation, and mtDNA content but not in citrate synthase activity. By contrast, when central regions of gliomas are compared to central region of brain metastasis, we found increased mtDNA oxidative damage, an upward in antioxidant systems, a greater mitochondrial protein content and a trend towards a higher LDH activity. Moreover, the central region of gliomas showed lower glutathione peroxidase/MnSOD activity ratio than central region of metastasis. The aforementioned differences in cancer cells located in central regions were not found in peripheral tumoral areas in gliomas or brain metastasis. Interestingly, our data suggest that there is an heterogeneity in redox balance and mitochondrial features between primary and metastatic human tumors in the brain. Moreover, this different behaviour is not randomly distributed within the tumor mass but identified in the central region. P133. DISTRIBUTION OF INOS IN RAT EXPERIMENTAL GLIOMA H. C. Nittby, L. G. Salford, G. Skagerberg; Department of Neurosurgery, Lund, Sweden Aim: The study aimed to clarify the distribution of inducible nitric oxide synthase (iNOS) expression in rats inoculated with cultured glioma cells. Introduction: Nitric oxide (NO) is a primary messenger with important effects in the nervous-, vascular-, and immune systems. iNOS has been demonstrated in human gliomas and in both astrocytes and microglia after appropriate stimuli. Effects of NO in animals with brain tumors may thus be mediated by iNOS activity in the tumor, as well as in the host tissue. In this study we mapped the distribution of iNOS both in the implanted tumor tissue and in the surrounding brain parenchyma of the host. Material and Methods: Cultured rat glioma cells (N32 or RG2) were injected into the striatum of young adult Fischer rats. After 2–3 weeks survival the rats were sacrificed, perfused with formalin, and the brains were dissected. Slabs from the level of the tumor inoculation were further fixed and cut on a freezing microtome at 40 μm. The sections were incubated with primary iNOS antiserum and processed according the ABC-method for visualization of iNOS immunoreactivity, utilizing DAB as a chromogen. Results: The tumor tissue, which usually occupied a large, but well circumscribed, part of the striatum on the inoculated side was diffusively positive for iNOS. In the surrounding host parenchyma iNOS positive cells sometimes accumulated at the border of the tumor. Further away from the tumor a general overexpression of iNOS positive cells (compared to controls) was seen, both in some cortical subregions and in the white matter. At the same time, an apparent relocalization of iNOS positive elements (compared to controls) was observed. Discussion: This study documents the presence of iNOS in inoculated tumors as well as in the host brain. We propose that the iNOS expression seen within the glioma, might promote further tumor growth mainly through angiogenesis and immunsuppression, whereas the more general iNOS overexression seen further away from the tumor, might in part be an unspecific response of the host immune system, where NO produced by microglia could serve the role of inducing apoptosis in tumor cells. These different sources may well be differentially regulated, which should be taken into account when studying the effects of NO on brain tumors. P134*. LEPTOMENINGEAL CARCINOMATOSIS: PROGNOSTIC IMPLICATIONS OF CLINICAL AND CEREBROSPINAL FLUID FEATURES IN 70 PATIENTS J. Bruna1, L. González1, J. Miró1, R. Velasco1, M. Gil2, A. Tortosa3; 1Institut de Investigació Biomèdica de Bellvitge. Hospital de Bellvitge. Neurology department, Hospitalet del LLobregat, Spain, 2Hospital Duran i Reynals. Institut Català d'Oncologia. Medical Oncology department, Hospitalet del LLobregat, Spain, 3Institut de Investigació Biomèdica de Bellvitge. Department of Basic Nursing. Universitat de Barcelona, Hospitalet del LLobregat, Spain Leptomeningeal carcinomatosis (LC) represents a devastating metastatic complication of systemic cancer, with a dismal prognosis and increased mortality. Available therapies, including intrathecal administration of chemotherapy and radiotherapy, provide limited benefits and can be toxic. Furthermore, the few studies focused on the evaluation of prognostic factors in patients with LC have resulted in contradictory results. Thus, treatment of LC remains controversial and no straightforward guidelines exist in the literature. The aim of the present study was to identify prognostic markers related to LC survival in order to better select patients eligible to be intensively treated. Seventy patients with the diagnosis of LC and primary solid tumor were reviewed, and clinical data, cerebrospinal fluid (CSF) parameters, tumor-related characteristics, and treatment data were registered. The impact of single parameters on overall survival was determined by both univariate and multivariate analyses. In the univariate analysis, factors related to overall survival were age, sex, Radiation Therapy Oncology Group (RTOG) neurological functional score, levels of glucose in CSF, breast cancer as primary tumor, infratentorial symptoms, and intrathecal treatment. The multivariate analysis revealed that only RTOG score ⩽ 2 (p=0.028), level of glucose in CSF ⩾ 2.7 mmol/L (p=0.001), the presence of infratentorial symptoms at onset (p=0.026), and intrathecal treatment (p<0.001) were independently associated with higher survival rate. The influence of predictive markers was further evaluated by calculating an index to predict the probability of survival including those independent pretreatment prognostic variables (RTOG score, glucose on CSF, and infratentorial symptoms). This prognostic index allowed an accurate classification of patients according to their probability of survival (HR: 3.06; 95% CI: 1.67–5.59; p=0.0003). After adjusting the prognostic score for primary tumor and treatment, this index maintained its predictive value. In conclusion, RTOG score, glucose levels in CSF, presence of infratentorial symptoms at onset, and intrathecal treatment were independently associated with longer overall survival in patients with solid tumors and LC. Additionally, pretreatment variables could help to better select patients who are more likely to benefit from intensive chemotherapy treatment, although further validation in prospective studies is necessary. P135. SURVIVAL AT 3, 6, 10, AND 12 MONTHS IN 22 PATIENTS WITH NEOPLASTIC MENINGITIS TREATED WITH INTRATHECAL LIPOSOMAL CYTARABINE (DEPOCYTE) E. Le Rhun1, M. Baranzelli1, M. Faivre Perret1, F. Dubois2, J. Bonneterre1; 1Centre Oscar Lambret, Lille, France, 2Centre Hospitalier Régional Universitaire, Lille, France Introduction: Around 5–8% of patients with solid tumors develop neoplastic meningitis, which if untreated, confers a median survival time of ∼4–6 weeks. Reports suggest that a combination of intrathecal (IT) liposomal cytarabine (DepoCyte), systemic chemotherapy, and supportive care may improve survival. We report survival at 3, 6, 10, and 12 months in 22 patients with neoplastic meningitis treated with IT DepoCyte and supportive care, with or without systemic chemotherapy, at Centre Oscar Lambret, Lille, in 2007. We also examine correlations between patient characteristics and survival. Materials and Methods: Patients diagnosed with neoplastic meningitis in 2007, on the basis of cerebrospinal fluid (CSF) cytology and/or cerebrospinal MRI, were prospectively followed up. At the time of submission of this abstract, 22 had either received at least six injections of IT DepoCyte, or had died before the sixth injection. Systemic chemotherapy was given in 12 patients (55%), at the discretion of the referring oncologist. The Statview software package was used to analyze population characteristics and detect statistical correlations. Results: Of the 22 patients, 15 (68%) were women. Their median ± SEM age was 52 ± 10 years. The original solid tumor was breast cancer in 14/22 (64%), and brain metastases were present in 17 (77%). KPS at diagnosis was ⩾ 70 in 9/22 (41%). CSF cytology was positive in 18 (82%); cerebrospinal MRI was also positive in 18 (82%). Overall survival in the treated patients was 59%, 45%, 20%, and 9% at 3, 6, 10, and 12 months following diagnosis, respectively. Neither original tumor type nor age at diagnosis correlated with survival at any stage. However, there was a trend toward higher survival at 3 and 6 months in the 9 patients with KPS ⩾ 70 at diagnosis (p<0.07), although 1 patient still alive at 10 months had a KPS at diagnosis of 50. Conclusions: Our results confirm that DepoCyte treatment may be useful in treating this cancer complication, which therefore needs to be detected as early as possible. Further studies should investigate the response to treatment in patients with different types of solid tumor, and in particular its relationship with tumor characteristics. P136. LONG TERM STABILIZATION OF LEPTOMENINGEAL AND SOLID CNS METASTASES FROM BREAST CANCER WITH COMBINED INTRATHECAL LIPOSOMAL ARA-C AND SYSTEMIC TEMOZOLOMIDE A. L. Hoffmann1, J. H. Buhk2, M. Nitsche3, H. M. Strik1; 1Department of Neurology, Göttingen, Germany, 2Department of Neuroradiology, Göttingen, Germany, 3Department of Radiation Oncology, Göttingen, Germany Objective: CSF dissemination of breast cancer (BC) is dismal with a median survival of 8–12 weeks. We present long-term stabilization with liposomal Ara-C (Depocyte), dose-dense temozolomide (TMZ), and radiotherapy in two patients with leptomeningeal and solid CNS metastases from BC. Case Reports: Two 42- and 43-year-old females had CSF-spread and disseminated solid spinal, one also with cerebellar metastases, from intensely pretreated Her2+ BC received intrathecal (ith) Depocyte every second week and TMZ 100 mg/m2 day 1–5/7 after irradiation of symptomatic solid tumors. Neurological symptoms improved in both pts. Spinal metastases remained stable, the cerebellar mets. decreased by 50%. CSF cell counts normalized, only single malignant cells persisted. Progression occurred after 6 and 7 months. One patient died after 9 months, the other is alive and stable at a lower level 12 months after CNS dissemination. Discussion: CSF- and solid CNS-metastases from breast cancer usually occur after intense pre-treatment. Prognosis is bad, also because active CNS-penetrating systemic drugs are lacking. The value of ith. chemotherapy is unclear. Despite conflicting results in the literature, some data indicate that combined systemic and ith. chemotherapy may be superior to either treatment option alone. Ith. liposomal Ara-C is active in meningeal disease especially from hematopoietic cancer. CSF-spread from solid tumors can be improved in terms of cytological and sometimes short-term clinical response, but long-term stabilization is rare. Temozolomide is an orally available alkylating drug with favourable toxicity profile and good penetration into the central nervous system. In CNS metastases from breast cancer, however, conventionally applied temozolomide (200 mg/m2 day 1–5/28) had only limited activity. Based on good results with recurrent gliomas, we treated our patients with dose-dense near-continuous application of TMZ 100 mg/m2 day 1–5/7. This systemic therapy was combined with ith. Depocyte which appears to be the most promising drug for CSF-chemotherapy to date. The long-term stabilization of both patients indicates activity of this combined ith. and near-continuous systemic approach. P137. PEMETREXED FOR PATIENTS WITH CENTRAL NERVOUS SYSTEM (CNS) METASTASES S. A. Grimm, J. Patel, M. Cianfrocca, W. Gradishar, M. Mulcahy, V. Kaklamani, J. Von Roenn, S. Kennedy, J. Raizer; Northwestern University, Feinberg School of Medicine, Chicago, IL, United States Background: Pemetrexed is a multi-targeted anti-folate with activity in solid tumors. Methods: Patients with metastatic disease to the CNS were treated with Pemetrexed. Patients signed IRB approved consent prior to treatment. Adequate laboratory data, KPS > 60, and age > 18 years were required. Patients with effusions or fluid collections were eligible if they were drained prior to treatment. Patients received 500 mg/m2 (n=2) or 900 mg/m2 (n=8) of Pemetrexed every 3 weeks. All patients received folic acid and vitamin B12 for 7 days prior to treatment. Results: Ten patients (6 women) with a median age of 51 (range 25–71) were treated. Median KPS was 90 (range 80–100). The primary tumor sites were breast (5), lung (4), and colorectal (1). The patients received a median of 2.5 (1–10+) doses. Four of the 5 breast cancer patients had prior treatment with high dose systemic methotrexate. Two lung cancer patients had SD (1 for 27 weeks, one withdrew after 3 doses) and 2 had PD. Three patients with breast cancer had PR, 1 had a mixed response, and 1 had PD. The patient with colorectal cancer had PD. No major toxicity was seen. Conclusion: Pemetrexed is well tolerated in patients with metastatic disease to the CNS. Although the number of patients is small, responses were seen in patients with breast cancer, even in those with prior systemic methotrexate treatment. P138*. STEREOTACTIC RADIOSURGERY BY HELICAL TOMOTHERAPY SYSTEM FOR METASTATIC BRAIN TUMORS USING 11C-METHIONINE PET S. Takenaka1, K. Miwa1, J. Shinoda1, M. Matsuo2, T. Ueda3, K. Yokoyama3, J. Yamada3, H. Yano4, T. Iwama4; 1Chubu Medical Center for Prolonged Traumatic Brain Dysfunction, Minokamo, Gifu, Japan, 2Department of Radio-oncology, Kizawa Memorial Hospital, Minokamo, Gifu, Japan, 3Department of Neurosurgery, Kizawa Memorial Hospital, Minokamo, Gifu, Japan, 4Department of Neurosurgery, Gifu University School of Medicine, Gifu, Japan. Objective: The objective of this study was to evaluate characteristics of 11C-methionine (MET) positron emission tomography (PET) images following stereotactic radiosurgery (SRS) by Helical Tomotherapy (HT) system for metastatic brain tumors. Methods: Twenty-five lesions in 12 patients who underwent SRS for metastatic brain tumor and were free from local progression were enrolled. All patients were treated on HT system with intensity-modulated radiotherapy (IMRT) beams. The gross tumor volume (GTV) corresponded to the region of intensive MET uptake. The planning target volume (PTV) encompassed GTV-1 plus a 2mm margin. The prescription dose was 20 Gy. The MET-PET scans were performed before SRS, 3 months after SRS, and 6 months after SRS. Characteristics of MET uptake post-SRS were evaluated quantitatively and qualitatively. Quantitative evaluation consisted of measurement of the ratio of median standardized uptake value in the target lesions compared to contralateral normal brain (T/N ratio). Qualitative evaluation consisted of visual analyses of the extent of intensive MET uptake. Results: The T/N ratio were 1.84 ± 0.44, 1.16 ± 0.24, and 1.08 ± 0.02 (mean ± standard deviation) in the pre-SRS group (Group A), in the 3 month post-SRS group (Group B) and in the 6 month post-SRS group (Group C), respectively. The difference in the mean T/N ratio between the Group A and Group B and between Group A and Group C were significant. By qualitative evaluation, the extent of intensive MET uptakes did not increase within 6 months following SRS. Conclusions: We show examples of metastatic brain tumors demonstrating significant decrease in MET uptake following SRS with HT system. SRS with HT planned by MET-PET is a useful methodology and MET-PET images have distinct efficacy for treatment planning using SRS and monitoring response after SRS. P139. OUTCOMES OF WHOLE BRAIN RADIATION THERAPY FOR METASTATIC DISEASE: A RETROSPECTIVE POPULATION-BASED COHORT ANALYSIS M. Cameron, C. Kersten, R. van Helvoirt; Center for Cancer Treatment, Kristiansand, Norway Background: Several clinical elements influence a physician's decision with regard to whole brain radiation treatment (WBRT) of metastases, a frequently used but relatively poorly studied palliative treatment modality. To select those patients who are expected to have a treatment benefit is a challenge. Objectives: To identify factors that convey a particularly poor prognosis on patients treated with WBRT. Patients/Methods: From 01.2001 to 07.2007, we treated 213 patients with WBRT for intracranial metastases, based on a population of 250,000. The patients (median age 61) represented 14 diagnostic groups, the largest being lung cancer (59%), breast cancer (13%), and malignant melanoma (10%). There were 57 patients with a solitary metastasis. 32 were operated on, and 4 received gammaknife treatment prior to WBRT. 181 patients received standard fractionation (3Gy × 10 or 3.5Gy × 8), six received 4Gy × 5, and 5 received dose-escalated treatment up to 50Gy. 21 patients did not complete the intended treatment but were included in the final analysis. Results: Median survival of the entire cohort was 4.0 months. Six-month survival was 36% and 12-month survival was 14%. Only 4% survived >24 months. Patients with lung cancer had a significantly poorer median survival (3.0 months) than did patients with other primaries (5 months; p=0.005). Differences between patients with good (ECOG 0-1) and poor (ECOG 2–3) performance status were also significant, with 5.0 and 2.0 months median survival respectively (p<0.005). Median survival among patients younger than 60 years (5.0 months) was greater than among patients 60 years or older (3.0 months; p=0.01). Patients with a solitary intracranial metastasis had increased median survival (5.0 months) in comparison to those with multiple (including meningeal) metastases (3.0 months; p<0.005). The 5 patients given dose-escalation were selected for their presumed increased benefit and had a median survival of 13 months. Conclusions: Our center has a median survival after WBRT of intracranial metastases comparable to published results. Lung cancer primary, ECOG ⩾ 2 and age ⩾ 60 confer a poorer prognosis. A solitary metastasis confers a somewhat better prognosis. These criteria could help guide physicians to better select patients for whom the benefits of WBRT are unlikely to outweigh its drawbacks and to opt for a “best supportive care” strategy. Prospective randomized studies are needed. P140*. BRAIN METASTASES AND RADIOSURGERY: 6 YEARS FOLLOW UP COMPARING THE RPA, SIR AND BSBM PATIENT STRATIFICATION SYSTEMS D. Devriendt1,2, F. De Smedt1,2, P. David3, N. Massager2; 1Institut Jules Bordet, Brussels, Belgium, 2Gamma Knife Center of ULB, Brussels, Belgium, 3Erasme Hospital, Brussels, Belgium Objective: To compare the three systems of stratification, concerning the recursive partitioning analysis (RPA), the score index for radiosurgery (SIR), and the basic score for brain metastases (BSBM) with a 6 years follow up for patients with brain metastases and treated by radiosurgery. Material and Methods: Between December 1999 and December 2005, 267 patients with more than 700 brain metastases were treated with a Leksell Gamma Knife model C. Median marginal dose was 20 Gy at a median 50% isodose. There were 45% lung cancer, 22% breast cancer, 19% melanoma, and 15% other primary tumors. Results: Median survival (MS) for the entire population is 11 months. Univariate analysis confirms the predictive value of the three systems. MS was 17.5 months for RPA class I, 11 months for RPA class II, and 3 months for RPA class III (p < 0.0001). According to SIR system, MS were 19, 11, 4, and 4 months for scores 8 to 10, 5 to 7, 3 to 4, and 0 to 2, respectively (p < 0.0001). According to BSBM system, MS were 20, 11, 6, and 3 months for score 3, 2, 1, and 0 points, respectively (p < 0.0001). The multivariate analysis identifies as significant factors the KPS, the SIR, and the BSBM models. Conclusions: This comparative study confirms the usefulness of all three systems of classification to predict the outcome of patients treated by radiosurgery. Patients who will benefit the most from RS belong to the groups RPA class I-II, SIR 5–10, and BSBM 2–3. Patients with BSBM score 0, SIR score 0 to 3, and RPA class III have a MS around 3 months and are not likely to benefit from radiosurgery. P141. GAMMA KNIFE STEREOTACTIC RADIOSURGERY FOR BRAIN METASTASIS M. E. Kusak, N. Martinez, J. Gutierrez, G. Rey, R. Martinez; Hospital Ruber Internacional, Madrid, Spain The incidence of brain metastases has increased as a result of the effectiveness of treatments for systemic cancer, and will continue to be an emergent medical challenge. Brain metastases occur in at least about 25% of cancer patients, and probably this incidence will increase as prolonged survival is expected. On the other hand, brain metastases are ideal targets for stereotactic radiosurgery treatments, because of their shape, size, and, generally, number. We here present the results of a single referral center for gamma knife stereotactic radiosurgery treatment. As of August 2007, 476 treatments had been performed on 406 patients. Updated follow up have been obtained in 218 cases (46.9%). Sixty percent of these were males, 40% females, with a mean age of 55 years. Forty-five percent had been previously treated with whole brain radiotherapy or gamma knife stereotactic radiosurgery, and 20% had been previously been operated on. Forty-four percent of patients were treated for one metastasis, 37% for between two and five metastases, 15% for between five and ten metastases, and 4% for more than ten metastases. Forty-five percent of primary tumors were lung cancers, 15% breast cancers, and 7% melanomas. The mean treatment volume has been 9.9 cc, with a mean dose of 16 Gy. The mean follow up has been 12 months. The local control rate has been of 96%. With these and other reported results, gamma knife treatment should be taken into account as an initial, as some groups suggest, or as adjuvant treatment for brain metastases. P142. SARCOMA METASTATIC TO THE BRAIN: A SERIES OF 35 CASES AND CONSIDERATIONS ON 27-YEAR EXPERIENCE M. Salvati1, C. Brogna1, A. D`elia1, A. Melone1, J. Lenzi1, S. Bastianello2, A. Raco1, A. Santoro1, F. Giangaspero3,1, R. Delfini1; 1Neuroscience-Neurosurgery department, Sapienza University, Rome, Italy, 2Neurologic Institute C. Mondino, Pavia, Italy, 3Neurosurgery department, INM Neuromed IRCCS, Isernia, Italy We report our 27-year experience on 35 cases of supratentorial brain metastases from sarcoma, including 10 osteosarcomas, 7 leiomyosarcomas, 5 Ewing sarcomas, 4 malignant fibrous histiocytomas, 3 Alveolar Soft-Part sarcomas (ASPS), 2 rhabdomyosarcomas, 1 liposarcoma, and 3 unclassified sarcomas treated on a single institution. The first 15 cases were objects of previous publication. Median survival after craniotomy was 9.8 months (range: 4–24). Patients with preoperative Karnofsky Performance Score (KPS)>60 was 13.1 months (range: 6.5 to 24 months) versus 5.4 months for those patients with a KPS⩽60 (p=0.03). Patients with more than one lesion were 8, 6 of which were treated in the last ten years. The three patients with ASPS are alive at 15 and 20 months for the first two (they were lost at follow-up) and 24 months for the other. We conclude that surgery is more effective in treating selected patients with sarcoma metastatic to the brain, and that patients with metastasis from ASPS have good prognosis if they underwent surgical treatment. The complete removal of all brain metastases “en bloc” and a KPS>60 are associated with the best prognosis. Finally, it appears that surgical indication for multiple brain metastases from sarcoma increased during the last ten years. P143. NEURO-OPHTHALMOLOGIC MANIFESTATIONS OF METASTATIC CANCER S. Muñoz1,2, V. Cuadrado2, J. Arruga1,2, L. Castillo2; 1Ophthalmology Department-Hospital Universitari de Bellvitge, L`Hospitalet de Llobregat, Spain, 2Ophthalmology Department-Hospital Universitari Sagrat Cor-Institut Català Retina, Barcelona, Spain Background: Malignant tumors arising in any part of the body may spread to the central nervous system. Most metastases result from haematogenous dissemination of the tumor to skull bones, brain parenchyma, subarachnoid space, and the orbit. They produce uncommonly neuro-ophthalmologic manifestations either as a presenting sign of an unknown cancer or as a sign of relapse. Methods: A multicentric retrospective study was conducted to determine the prevalence and the nature of this disorder in the neuro-ophthalmology clinic. Case notes of patients evaluated from 2001 to 2007 in Hospital Universitari Sagrat Cor, Barcelona and Institut Català de Retina, Barcelona were reviewed. Results: Among 700 consecutive patients seen in the aforementioned clinics, 16 individuals had neuro-ophthalmologic manifestations of systemic cancer. There were 10 men and 6 women whose ages ranged from 39 to 82 years. Time to seek for attention was within 10 days and 4 months. There was a previous history of systemic cancer in all cases. Nine of them had known metastatic disease intracranially or elsewhere. However, in nearly half of the patients (7 out of 16) neuro-ophthalmologic symptom represented the first sign of metastasis or tumor relapse. The most common presenting complaints were diplopia in 43% and visual loss in 37%; ptosis and anisocoria were less common. Eight individuals had afferent pathway involvement consistent with papilledema, optic neuropathy, or retrochiasmal lesion. Motility disturbance was seen in twelve patients due to motor ocular nerve damage, to infiltration of extraocular muscles and orbit, or to interruption of the ocular sympathetic pathway. Three patients had involvement of both the afferent and efferent systems. Lung and breast tumors were the most common malignancies in the series accounting each for 25%. Less usual primary tumors were located at the Meckel's cavum, bone marrow, prostate, and colon. There was a clear predominance of breast cancer for females with two-thirds of these cases, whereas in male three types accounted the majority of primary neoplasms (lung 30%, cavum 20%, and leukemia 20%). Conclusions: The prevalence of neuro-ophthalmologic manifestations secondary to systemic cancer seen in these clinics was rather low. Full neuro-ophthalmologic assessment and complete examination must be done not to overlook multiple lesions. In the clinical setting of previous history of malignancy even with complete remission, and any neuro-ophthalmologic symptom, intracranial spread or infiltration must be always ruled out. P144. PRIMARY EXRADURAL DORSAL SPINE NON-HODGKIN LYMPHOMA: CASE REPORT P. G. Papanikolaou, K. S. Barkas, T. S. Paleologos, E. K. Papadopoulos, A. Venetikidis, E. M. Chatzidakis, M. Fratzoglou, T. Mourouzidis, T. Kyriakou, K. Kazdaglis; General Nikaia Piraeus Hospital, Neurosurgical Department, Athens, Greece We present an interesting case of an extradural primary non-Hodgkin lymphoma of thoracic spine. A male patient, 55 years of age, presented with a short history of lumbar pain and bilateral limb weakness. At neurological examination there was a mild spastic paraparesis with sensation disorders by T6 dermotome. Dorsal spine magnetic resonance imagine revealed a homogenous, purely extradural space occupying lesion, extending from T7 to T10 vertebrae, located posteriorly without any signs of bone invasion. The tumor was radically resected via a T7 to T10 laminectomy. There was no dural invasion. Postoperative course was uneventful with rapid improvement of paraparesis. Histology revealed a follicular non-Hodgkin lymphoma grade I. Investigation for any other lesions at the rest of body was negative. There were no findings of any immunosuppressive disease. Patient was submitted to radiotherapy and chemotherapy. At 24 months follow up he is very well and free of recurrence. Primary extradural lymphoma is a very rare spinal tumor. A possible thoracic spine space occupying lesion should be suspected in cases of persistent lumbar pain with limb weakness. P145. INTRALUMINAL LIPOSOMAL CYTARABINE CHEMOTHERAPY OF AN INTRACRANIAL TUMOR CYST: A CASE REPORT B. Weiss, B. Wrede, P. Turowski, G. Demleitner, O. Peters; University Regensburg, Regensburg, Germany Background: We present a male patient aged 17 at diagnosis of an alveolar rhabdomyosarcoma (T4/pN2c/M0) of the paranasal sinuses with a tumor cyst (76 m3) extending per continuitatem into the left frontal cerebral lobe with no contact to the cerebrospinal fluid (CSF) system. Additionally to the systemic sarcoma chemotherapy, we locally treated the tumor cyst with repeated intraluminal liposomal cytarabine (DepoCyt) injections. DepoCyt is composed of the pyrimidine analog cytarabine which is encapsulated in multivesicular, lipid-based particles. After a single intrathecal injection these particles cause a sustained release of cytarabine, maintainig cytotoxic concentrations in the CSF up to 14 days. Procedure: At day 3 of the i.v. sarcoma chemotherapy (CHT; CWS 2002) the intracranial tumor cyst volume increased, causing symptoms of elevated intracranial pressure. Serial punctures via an implanted Rickham reservoir decreased the cyst volume and improved the symptoms. The cystic fluid showed a massive amount of tumor cells. Because of the recurrent increase in cyst volume we started an intraluminal CHT by injection of DepoCyt via the Rickham reservoir. The injections were given at day 24 (1 mg), 28 (5 mg), 35 (5 mg), and 49 (5 mg) after initiation of the i.v. sarcoma CHT. DepoCyt trough concentrations of the cystic fluid were determined prior to the injections. Meanwhile, the i.v. sarcoma CHT was continued, including an interposed local irradiation of all primary tumor sites. Results: After 4 intraluminal DepoCyt injections and concomitant i.v. sarcoma CHT, a partial shrinkage of the cyst was observed by MRI/sonography prior to the local irradiation. After the third DepoCyt injection no more cystic tumor cells were microscopically seen. The tumor cyst completely collapsed at day 53 of the i.v. sarcoma CHT and DepoCyt injections were terminated. The lowest DepoCyt concentration was 2.1 mg/l at day 5 after the first injection (1 mg). The highest concentration was 7.0 mg/l at day 8 after the second injection (5 mg). These concentrations are in the range of the ventricular CSF after an intraventricular injection of 75 mg DepoCyt in adults.The patient received 4 DepoCyt injections without side effects. Two months after termination of the primary CHT the patient experienced a multifocal relapse, but a residual of the tumor cyst was not observed. Conclusion: We conclude that the intraluminal liposomal cytarabine contributed to the disappearance of the intracranial tumor cyst and that inoperable or CHT resistent intracranial malignant cysts could locally be treated with the described strategy P146. RISK FACTORS ASSOCIATED WITH DEVELOPMENT OF THROMBOTIC EVENTS IN PATIENTS WITH HIGH-GRADE GLIOMA R. Prat1, I. Galeano1, J. Todolí2, R. Amador3, L. Bataller4, M. Martín5, G. Reynes5; 1Hospital Universitario La Fe, Dept. of Neurosurgery, Valencia, Spain, 2Hospital Universitario La Fe, Dept. of Internal Medicine, Valencia, Spain, 3Hospital Universitario La Fe, Dept. of Radiation Oncology, Valencia, Spain, 4Hospital Universitario La Fe, Dept. of Neurology, Valencia, Spain, 5Hospital Universitario La Fe, Dept. of Medical Oncology, Valencia, Spain Introduction and Objectives: Patients (pts) with with high-grade glioma (HGG) have an increased risk of thrombotic events (TE). Aim of the study: to identify risk factors associated to the development of deep venous thrombosis (DVT) or pulmonary thromboembolism (PTE) in pts with HGG. Materials and Methods: We have selected TE among pts with HGG from 2 sources: hospital discharge data and Internal Medicine Dpt. files. Results: We have studied 24 HGG pts with TE. Men: 13, women: 11. Tumor location: lobar: 18; deep brain structures: 6; right/left: 10/14. Tumor necrosis on MRI: 22. Surgical resection: 18. Stereotaxic biosy: 4. No surgery: 2. Tumor remain: 20. Two pts developed general complications after surgery, and 10 pts presented motor deficit. Comorbidity: Diabetes mellitus: 6. Ischemic cardiopathy: 1. Heart failure: 1. Previous treatments: All pts received dexamethasone before surgery. Low molecular weight heparin (LMWH): 18. Post-operative compression socks: 14. Pneumatic pressotherapy: 1. Onset of TE: 11 pts after radiation therapy (RT), 13 pts after chemotherapy (CT). Type of TE: 11 pts developed a DVT only, and 13 pts PTE and TVP. Symptoms: dyspnea (11), low extremities edema (9), hemoptysis (3), and pain (1). All DVT occurred in low extremities. Mean fibrinogen: 377 mg/dl (45–780). Mean platelet count: 217000/mL (84000–394000). Mean D-dimers: 3458 ng/mL (827–6683). Treatment: 18 pts received LMWH, and 6 pts calcic or sodic heparin. Insertion of a vena cava filter: 1 pt. Thrombolysis: 1 pt. Chronic treatment: LMWH in 15 pts and acenocumarol in 9 pts. One pt had a brain hemorrhage. At last follow up, Karnofsky Performance Status (KPS) was 40–50 16 pts, and higher in 8 pts. Seven pts are alive with active brain tumor, and 17 pts have died (tumor: 10 pts; TE: 5 pts; other: 2 pts). A positive correlation with PTE was found for lobar location (p<0.005), tumor volume ⩾38.84 cc vs. 0/< 29.63 cc (p<0.05), surgical resection vs. biopsy (p<0.05), and high fibrinogen levels (⩾ 468 vs. 0/< 292 mg/dL) (p<0.05). No correlation was found between PTE and pre- or post-surgery KPS, tumor histology, partial surgical resection, post surgical motor deficit, thromboembolic prophylaxis, RT, CT, or D-dimers level. Conclusions: Thromboembolic prophylaxis and strict surveillance are needed in glioma pts, specially after surgical resection of large tumors. P147. STROKE IN CANCER PATIENTS S. Oberndorfer, V. Nussgruber, R. Corina, O. Berger, W. Grisold; LBI Neurooncology, Vienna, Austria Stroke is a common disabling disease and can aggravate the burden of patients already suffering from cancer. Several cancer-specific types and causes of stroke in cancer patients have to be considered. However, there are controversies in the literature whether stroke in cancer patients has a similar incidence as in non-cancer patients. The purpose of the study was to evaluate the risk for hemorrhagic and ischemic stroke in cancer patients compared to non-cancer patients. Analysis of classical risk factors for stroke were also investigated. A retrospective analysis from 2003 to 2007, including 1274 stroke patients admitted to our stroke unit was conducted. From all patients, 12% had additional diagnosis of cancer. In the non-cancer population 84% had ischemic and 16% had hemorrhagic strokes. In cancer patients 87% had ischemic and 13% had hemorrhagic strokes. Vascular risk factors in cancer patients, including hypertension, atrial fibrillation, ischemic heart disease, smoking, hypercholesterolaemia and diabetes mellitus, showed no statistical significant difference as compared to the non-cancer population. Only for deep vein thrombosis (DVT) and pulmonary embolism (PE) was a statistical significant difference (9% in cancer patients vs. 4% in non cancer patients) was detected. In conclusion, the incidence of ischemic as well as hemorrhagic stroke in cancer patients is similar as compared to a non-cancer population. Also cerebrovascular risk factors do not significantly vary between cancer and non-cancer patients. The higher frequency of DVT and PE in cancer patients can reflect a coagulation disorder, which is a common finding in cancer patients. P148. THERAPEUTIC ANTICOAGULATION FOR RADIATION-INDUCED NEUROTOXICITY C. Happold1, U. Ernemann2, P. Roth1, W. Wick3, M. Weller1, F. Schmidt1; 1Department of General Neurology, Hertie Institute for Brain Research, Tuebingen, Germany, 2Department of Neuroradiology, Medical School, Tuebingen, Germany, 3Department of General Neuro-Oncology, Heidelberg, Germany Since survival of oncological patients has increased due to more effective therapy options, long-term radiation-induced injury and its treatment have become of greater interest. Here, we present a series of 8 patients with delayed radiation-induced neurotoxicity under therapeutic anticoagulation. Radiation injury occurred as cerebral lesion (n=3), cranial nerve lesion (n=1), or myelopathy (n=4). All patients had undergone radiation therapy and suffered new neurological deficits. MR imaging ruled out tumor recurrence. All patients were treated with heparin or warfarin. No patient experienced hemorrhage or any other anticoagulation-related adverse effect. Mild improvement was observed in two out of three patients with cerebral lesions and the patient with cranial nerve lesions. None of the patients with myelopathy improved. In conclusion, the present case series demonstrates that anticoagulation therapy is safe but has only modest activity in patients with delayed radiation-induced neurotoxicity. P149. PRIMARY CEREBRAL AMYLOIDOMA: CLINICAL FEATURES, IMAGING FINDINGS AND TREATMENT OPTIONS A. Lossos, M. J. Gomori, T. Siegal; Hadassah Hebrew University Hospital, Jerusalem, Israel Background: Amyloidoma is defined as a solitary localized tumor-like deposit of amyloid, in the absence of systemic amyloidosis. Amyloidoma is the least common presentation of tissue amyloid deposition and may be of AL-type or AA-type. Amyloidoma of soft tissues is extremely rare and occurs mainly in the mediastinum and abdomen. Primary cerebral amyloidoma is even more uncommon and only a few cases are reported in the English literature to date. The natural history of the disease is unknown and treatment with complete surgical removal may be beneficial. There are no recommendations for therapeutic approach to those patients with unresectable cerebral amyloidomas. Objective: To describe the clinical features, imaging findings, and treatment of surgically inaccessible primary cerebral amyloidomas. Patients: Two patients with primary cerebral amyloidomas were diagnosed and treated recently in our center. The first is a 60-year-old woman with a slowly progressive right hemiparkinsonism and an enlarging left basal ganglia lesion that was first identified 6 years prior to the current clinical presentation. The other is a 51-year-old woman with chronic right ear infection and a right temporo-parietal lobe lesion which was enlarging slowly over a 2-year follow up period. MRI of both patients showed an intraaxial space occupying lesion that enhanced on T1-weighted images with gadolinium. The lesions demonstrated intense uptake on FDG-PET. A stereotactic biopsy diagnosed cerebral amyloidoma of the AL-lambda type in the first patient and of an uncharacterized type in the other. Systemic evaluation was negative for plasma cell dyscrasia in both patients. As the clinical course was compatible with a progressive lesion which was surgically inaccessible, both patients were referred for conformal radiation therapy. Follow up evaluation of the first patient is still pending and the other patient has stable clinical and imaging findings after a 4-year period. Conclusions: Primary cerebral amyloidoma may present with clinical and imaging manifestations imitating a tumor-like lesion. FDP-PET shows intense uptake despite lack of known metabolic activity within the area of amyloid deposits. Radiation therapy may stabilize a progressive disease in patients with surgically inaccessible cerebral amyloidomas. P150. PRIMARY CENTRAL NERVOUS SYSTEM VASCULITIS MIMICKING BRAIN TUMOR A. Rodríguez-Hernández, A. Bollar, M. Arrazola, M. Urtasun, I. Ruiz, M. Armendariz, N. Samprón, P. Torres, I. Arrese, E. Urculo; Hospital Donostia, San Sebastian, Spain Background: Primary vasculitis of the central nervous system (PVCNS) is an extremely rare disorder featured by a misunderstood and immunologically mediated inflammation and necrosis of the cerebral vasculature. We report a PVCNS case with an unusual pseudotumoral presentation. Case Report: A 26-year-old male patient presented with a 3-week history of severe headache and vomiting. The fact that he was born in Guinea and has recently been there for some weeks was taken into account. The neurological exam showed a left hemianopsy. A CT scan and MRI were performed showing a right occipital mass suggesting glioma as first diagnostic possibility. The patient underwent cranial surgery, and a complete resection of a yellowish, non-infiltrating necrotic lesion was performed. Histopathological study described a hystiocitary and lymphoid of T-cell perivascular infiltrate with reactive gliosis and necrosis and without evidence of microorganism or malignancies. Lymphoid rearrangement displayed polyclonal proliferation. With highly suspicious diagnosis of central nervous system vasculitis, all kind of immunological and infectious diseases were discarded to confirm this hypothesis. Treatment with cyclophosphamide was instituted and patient's neurological deficits improved in two weeks. Three months later, new neurological deficit appeared. Cerebral MRI showed multifocal enhancing subcortical lesions. Treatment with methotrexate was begun and 3 months later lesions had disappeared on control MRI. The patient recovered from the deficits and remains asymptomatic one year later. Discussion: Because of its low incidence and the variability of clinical presentation, PVCNS is an entity of difficult diagnosis. Pseudotumoral isolated CNS angiitis is a rare form of clinical presentation that makes diagnosis even more complicated. Three diagnostic criteria have been defined: CNS dysfunction unexplained by other processes, cerebral angiography, and/or biopsy showing characteristic features of vasculitis and no evidence of systemic vasculitis. Treatment with steroids alone or in combination with immunosuppressant agents is considered the initial therapy according to the clinical condition and disease progression. Doses and treatment duration are not well established. Cyclophosphamide is the preferred drug, although, as in our case, methotrexate has also been described as an alternative therapy. P151. NOCA R DI A SPP. INFECTIONS IN PATIENTS WITH PRIMARY OR METASTATIC BRAIN TUMORS N. Aizikovich, E. Shalom, R. Nir-Paz, T. Siegal; Hadassah Hebrew University Hospital, Jerusalem, Israel Background: Nocardia spp. are opportunistic gram-positive bacterial pathogens that can cause disseminated disease during serious immunosuppression such as organ transplantation, advanced HIV infection, lymphoproliferative neoplasia, or long-term corticosteroid use. The majority of cancer patients with nocradial infections have hematologic malignancies, and lymphopenia is observed in about 50%. Of the affected patients, more than half have received steroids within 30 days before onset of infection. This disposition implies that patients with brain tumors, who are exposed to high doses and long term use of corticosteroids, would be particularly prone to nocardial infections. Objectives: to evaluate the propensity of patients with brain tumors to nocardial infection. Methods: We surveyed all cases of nocardia spp. isolation between the years 1988 to 2007 using our institutional Clinical Microbiology computerized database. The records of patients with a history of either primary or metastatic brain tumors were examined for evaluation of risk factors, disease manifestations, and outcome. Results: 68 patients were found to have an isolation of nocardia spp. during the surveyed 19-year period. Of them 15 (22%) had a history of an underlying malignancy. Four patients (5.8%) suffered from either an active primary brain tumor (GBM-1, medulloblastoma-1) or CNS metastases (melanoma brain metastasis-1, leptomeningeal seeding of NSCLC-1). All 4 patients had received corticosteroids prior to diagnosis and 2 (with GBM and NSCLC) were on chemotherapy. At diagnosis, all 4 patients presented with normal or elevated WBC and with lymphopenia, which was severe in 3 of them (absolute lymphocyte count range: 100 to 800). Of particular interest is the GBM patient who developed the infection while on prophylactic sulfamethoxazole with trimethoprim, 4 weeks after the onset of concomitant radiation and daily temozolomide treatment. At that time she was severely lymphopenic with an absolute lymphocyte count of 100. Disease manifestations included fever (4), pulmonary involvement (4), septicemia (3), skin and soft tissue lesions (3), ocular findings (1), and brain abscesses (1). Three patients died of the acute nocardial infection. Conclusions: Nocardial infections are rare in patients with either primary or metastatic brain tumors despite extensive exposure to corticosteroids and chemotherapy. Severe lymphopenia is probably a major risk factor associated with a high fatality rate. P152. CISPLATIN INDUCED ENCEPHALOPATHY T. Ros1, M. Rebersek2, M. Boc2, J. Ocvirk2, S. Jereb3, L. Dolenc Groselj4, J. Knific5; 1Unit of Neurology, Institute of Oncology Ljubljana, Ljubljana, Slovenia, 2Department of Medical Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia, 3Department of Radiology, Institute of Oncology Ljubljana, Ljubljana, Slovenia, 4Institute of Clinical Neurophysiology, University Medical Center, Ljubljana, Slovenia, 5Department of Neuroradiology, Institute of Radiology, University Medical Center, Ljubljana, Slovenia Introduction: Cisplatin is an effective and widely used chemotherapeutic (CTh) agent. It is potentially neurotoxic, with a major toxic effect on peripheral nerves, occasionally on the central nervous system in the form of encephalopathy with or without seizures. We represent a patient with clinical signs and symptoms of cisplatin-induced posterior reversible encephalopathy syndrome (PRES). Case Report: A 41-year-old woman with progression of metastatic malignant melanoma (soft tissue, lung) was treated with second-line cisplatin-based regimen. Within the days shortly after the first cycle (dose of cisplatin 80 mg/m2), she developed nausea, vomitus, headache, severe pain in the site of abdominal subcutaneous metastases, and confusion. Few days later, she was experiencing somnolence, cortical blindness and aphasia, but without epileptic seizures. Diagnostic tests for excluding other causes of the condition were performed: progression of malignant disease, metabolic, iatrogenic, infectious, and vascular causes. She had typical neuroradiological changes in the form of edema in supra- and infra-tentorial areas with hyperintensity on T2-weighted MRI imaging, seen in the occipital cortex, cerebellum, basal ganglia, and corpus callosum. Electroencephalogram showed diffuse slow-wave activity with frequent generalized paroxysms of sharp waves and slow delta activity (1.5–2 Hz). EEG findings were compatible with reversible non-convulsive encephalopathy. After symptomatic treatment she slowly recovered. Repeated MRI disclosed an ischemic lesion in the occipital cortex, otherwise rarely seen complication of PRES, with partly to complete regression of other changes. She received second cycle of CTh with cisplatin in split doses. No central neurotoxicity recurred, but the malignant disease progressed, CTh was stopped and the patient died three months and a half after starting cisplatin-based CTh. Conclusion: According to published cases, cisplatin-induced central nervous toxicity is a rare complication in cancer patients, but we should be aware of it, as it is usually a reversible condition, which reqiure adequate treatment of seizures, symptomatic treatment and withdrawal of or cautiousness with cisplatin therapy. P153. SEVERE THALIDOMID NEUROPATHY IN A PATIENT WITH GLIOBLASTOMA S. Oberndorfer, B. Toth, E. Lindeck-Pozza, W. Grisold; LBI Neurooncology, Vienna, Austria Thalidomide was initially used as a sedative-hypnotic drug. It was withdrawn from general use because of its teratogenic side effects. Due to its anti-angiogenic properties, as well as modification of integrin receptors, it has become of interest for several oncological diseases, such as multiple myeloma, prostatacarcinoma, and also for malignant glioma. However, it may also induce a dose-dependent sensorimotor length-dependent axonal neuropathy, which has already been described by means of clinical, electrophysiological, and pathological features. Case Report: A 36 years old male was diagnosed for glioblastoma 9 years ago. He underwent surgery (three times), radiotherapy and chemotherapy (1 × cycle PCV, and temodal). Four years ago due to progressive disease adjuvant treatment with thalidomid 600 mg/day was started. One year later he developed clinical as well as electrophysiological signs and symptoms of peripheral neuropathy, which were slowly progressive until 2007, when a clinical and electrophysiological deterioration occurred. The glioblastoma showed radiologically stable disease. The patient exhibited moving fingers and moving toes, and was nearly unable to walk without help. Electrophysiologically, sensory nerve conduction of both upper and lower limbs was absent. At this time he received a cumulative dose of thalidomide of 800 g. The treatment was changed to lenalidomid, which lead to a slow clinical improvement of thalidomide induced neuropathy. Discussion: Thalidomie-induced neuropathy is reported to develop at cumulative doses with 20–30 g. Our patient developed slowly progressive classical clinical features of thalidomide-induced neuropathy over a long period of time (4 years) at cumulative doses with 800 g. This is the highest reported cumulative dose of thalidomide reported in the literature with clinical reversible features of thalidomide neuropathy. Whether the duration of the treatment or the total dose is responsible for the development of thalidomide-induced neuropathy is still a matter of discussion. P154. NEURONAL SURFACE ANTIGEN ANTIBODIES IN LIMBIC ENCEPHALITIS: CLINICAL-IMMUNOLOGICAL ASSOCIATIONS F. Graus1, A. Saiz1, M. Lai2, J. Bruna3, F. López1, L. Sabater1, Y. Blanco1, M. Rey4, T. Ribalta1, J. Dalmau2; 1Hospital Clinic, Barcelona, Spain, 2University of Pennsylvania, Philadelphia, PA, United States, 3Hospital Bellvitge, Barcelona, Spain, 4Brain Tumor Bank, Barcelona, Spain Background: Antibodies against neuronal surface antigens (NSA) are implicated in some types of limbic encephalitis (LE) that, unlike those associated with intraneuronal antibodies, usually improve with immunotherapy. At present, two antibodies types against NSA are characterized: anti-voltage-gated potassium channel antibodies (VGKC-ab) in patients with idiopathic LE and anti-N-methyl-D-aspartate receptor antibodies (NMDAR-ab) in patients with LE and ovarian teratoma. Objective: To report the frequency and type of antibodies against neuronal surface antigens (NSA-ab) in LE. Methods: Analysis of clinical features, neuropathological findings, and detection of NSA-ab using immunochemistry on rat tissue and neuronal cultures in a series of 45 patients with paraneoplastic (23) or idiopathic (22) LE. Results: NSA-ab were identified in 29 patients (64%; 12 paraneoplastic, 17 idiopathic). Thirteen patients had VGKC-ab, 11 novel NSA (nNSA)-ab, and 5 NMDAR-ab. nNSA-ab did not identify a common antigen and were more frequent in paraneoplastic than idiopathic LE (39% vs. 9%; p = 0.03). When compared with VGKC-ab or NMDAR-ab, the nNSA associated more frequently with intraneuronal antibodies (11% vs. 73%; p = 0.001). Of 12 patients (9 nNSA-ab, 2 VGKC-ab, 1 NMDAR-ab) with paraneoplastic LE and NSA-ab, concomitant intraneuronal antibodies occurred nine (75%). None of these 12 patients improved with immunotherapy. The autopsy of three patients with concomitant intraneuronal and NSA antibodies showed neuronal loss, microgliosis, and T-cell infiltrates in the hippocampus and amygdala. In contrast, clinical improvement was seen in 13 of 17 (76%) patients with idiopathic LE and NSA-ab (8 VGKC-ab, 4 NMDAR-ab, 1 nNSA-ab). In these cases the likelihood of improvement was higher than in those without antibodies (76% vs. 20%; p = 0.04). Conclusions: In paraneoplastic LE, nNSA-ab occur frequently and coexist with antibodies against intracellular antigens, and these patients are refractory to immunotherapy. In idiopathic LE, the likelihood of improvement is significantly higher in patients with NSA-ab than in those without antibodies. P155. DIFFUSE LARGE B-CELL LYMPHOMA IN GLIOMA PATIENTS TREATED WITH TEMOZOLOMIDE CHEMOTHERAPY S. Cordera1, E. Bottacchi1, M. Alvaro1, E. Joossens2, B. Neyns3; 1Regional Hospital Umberto Parini, Aosta, Italy, 2Dept. Medical Oncology, Middelheim ZNA, Antwerpen, Belgium, 3Medical Oncology, UZ Brussel, Laarbeeklaan 101, Belgium Temozolomide is a DNA alkylator used for the treatment of CNS gliomas. Sensitivity to temozolomide is correlated with cellular deficiency of the DNA repair protein AGAT resulting from hypermethylation of the MGMT gene promoter in glioma cells. Temozolomide is classically administered as a 5 out of 28 days regimen (200 mg/m2/day). Alternatively, temozolomide can be administered by extended daily dosing resulting in an up to 210 percent higher cumulative dose (e.g., 21 out of 28 days at 100 mg/m2/day). Such regimens more profoundly deplete AGAT in PBMC and may improve activity. The 21/28 days regimen is under study in 2 randomized phase III trials for patients with newly diagnosed low-grade glioma and glioblastoma. The 5/28 days regimen has low acute toxicity and no cumulative toxicity. In contrast, extended dosing regimens are associated with a high incidence (50–100%) of lymphopenia and associated opportunistic infections. Temozolomide has a strong mutagenic potential on mouse bone marrow cells but has not been associated to secondary malignancies. In 2007 three cases of temozolomide treated glioma patients came to our attention when developing a diffuse large B-cell lymphoma (DLBCL). One case concerns a 53-year old Italian female patient with a low-grade oligodendroglioma, diagnosed in 1998, who was initially treated with PCV chemotherapy. Following transformation to anaplastic oligodendroglioma in January 2006 she received radiotherapy with concomitant daily- and a total of 6 cycles of 5/28 days temozolomide. Seven months after the end of treatment she was diagnosed with a DLBCL of the neck. The other case concerns a Belgian male patient who was diagnosed with low-grade oligoastrocytoma at the age of 48 years. Following transformation to anaplastic oligoastrocytoma he was irradiated (September 2003). At first recurrence treatment with 5/28 days temozolomide and cetuximab failed (April 2005). Subsequently, 21/28 days temozolomide was successfully administered for 25 uninterrupted treatment cycles. In August 2008 a DLBCL of the stomach was diagnosed. The third case, reported by Nader Pouratian et al. (J. Neuronol 2007 May;82(3):281–8), concerns a patient with a low-grade glioma who developed a DLBCL after 12 cycles of 21/28 days temozolomide. Secondary DLBCL has been reported following treatment for Hodgkin Disease and in immunosuppressed organ transplant and HIV patients. Glioma patients treated with extended dosing regimens of temozolomide might be at risk for secondary DLBCL because of treatment associated immunosuppression and a high cumulative dose of a potentially carcinogenic DNA alkylating agent. P156. CYTOPENIAS IN PATIENTS WITH NEWLY DIAGNOSED HIGH-GRADE GLIOMAS RECEIVING RADIATION AND TEMOZOLOMIDE—WHO IS AT RISK? M. M. Mrugala1, S. K. Johnston1, M. C. Chamberlain1, J. V. San2, J. K. Rockhill1, J. Haug2, A. M. Spence1; 1University of Washington/Fred Hutchinson Cancer Research Center, Seattle, WA, United States, 2University of Washington, Seattle, WA, United States Chemoradiation using daily temozolomide (TMZ) and concomitant radiation (RT) followed by adjuvant TMZ has become a standard therapy for patients with glioblastoma (GBM). This regimen is also utilized to treat patients with anaplastic astrocytoma (AA), anaplastic oligodendroglioma (AO), and anaplastic oligoastrocytoma (AOA). It has been reported that patients with high-grade gliomas receiving chemoradiation are at higher risk for developing hematological toxicity. The goal of our study was to define potential factors such as tumor type, gender, age, and concurrent medications that may predispose patients to hematotoxicity from chemoradiation. We reviewed medical records of all adult patients with high-grade gliomas who were treated at our institution from 2005 to 2007. We included patients who were treated with the regimen of daily TMZ (75 mg/m2) and RT (average dose of 60 Gy) for six weeks. We recorded laboratory values, demographics, tumor type, concurrent medications, type, grade, and duration of complications. Confidence intervals were calculated using Wilson's score method. We identified 48 patients. Thirty-seven (77%) had GBM, 4 (8%) AA, 3 (6%) AO, and 4 (9%) AOA. Median age was 55 years (24–78). Fourteen (29%) were women, 34 (71%) were men. Forty-two (87%) patients were on AEDs at the start of therapy. Thirty-three (69%) were taking phenytoin, 4 (8%) levetiracetam, 2 (4%) carbamazepine, 2 (4%) valproic acid, and 1 (2%) lorazepam. Of those on AEDs, 24 (57%) had a documented seizure prior to and/or during RT/TMZ. Eighteen patients (43%) not on AEDs had not had a documented seizure. Add-on AED was introduced in 12 (25%) patients (levetiracetam in 20%, valproic acid in 2%, and lorazepam in 2%). Of those patients on an AED at the start of therapy 30 (71%; 95%CI, 56%–83%) developed hematologic toxicity vs. 5 (83%; 95% CI, 44%–97%) not on an AED. Thirty-two (68%) patients were receiving dexamethasone and 8 (17%) were receiving sulfamethoxazole. Overall, 35 (73 %; 95% CI, 59%–83%) patients developed hematologic toxicity, 5 (10.4%; 95%CI, 5%–22%) grade III or IV. All women developed hematotoxicity compared to 62% of men. Duration of blood counts suppression for women was greater than for men (3 vs. 1.7 weeks) and for patients with GBM greater than for patients with anaplastic tumors (4 vs. 1 weeks). Twelve per cent of patients who were 65 or older had to stop chemotherapy due to cytopenia vs. 7% of younger patients (<65). We found that degree and length of hematologic toxicity was more common in women, patients with GBM, and patients who were 65 or older. We identified that AEDs were over-utilized in this group of patients and their role in possible additive hematotoxicity remains suspect. Phenytoin was a preferred AED followed by levetiracetam. A larger prospective study is needed to evaluate if choice of AED (and other drugs) can influence the level of hematologic toxicity in this group of patients. P157. THE COST OF LIVING: THE QUALITY OF LIFE IN GLIOBLASTOMA PATIENTS Y. Krise, M. Rapp, M. Goeppert, W. Stummer, H. Steiger, M. Sabel; Department of Neurosurgery, Duesseldorf, Germany Objective: According to recent developments the best treatment options for glioblastoma (GBM) patients consist in additional alkylating chemotherapy (both local and systemic) and maximal resection, resulting in a substantial increase in overall survival. Evaluations of these concepts have mainly focused on survival parameters and toxicity. We therefore performed a prospective longitudinal quality of life (QoL) observation study including all primary GBM patients with initiation of treatment in our institution since 2006. Methods: 70 newly diagnosed GBM patients were included. All patients were treated according to Stupp. Patients were divided into partial resection (< 90% tumor resection, PR, n=35) and near complete resection (> 90% tumor resection; NCR, n=35). Upon recurrence (n=27) patients were treated with resection, implantation of Gliadel wafer and subsequent chemotherapy with TMZ (one week on/off) (Group A; n=9) or TMZ (one week on/off) with resection (Group B, n=7) or without resection (Group C, n=9). QoL was evaluated by three self-administered forms, the EORTC-C30-BCM20, FACT-Br and the Zung self rating depression scale (SDS) completed preoperatively, postoperatively, before and after each new treatment regimen and every three months. Results: Until recurrence no significant deterioration of QoL was determinded for patients with PR and NCR. Patients with PR demonstrated a trend towards a superior Global health score (GHS) (p=0.18) as patients with NCR and NCR patients demonstrated a trend to have more visual disorders (p= 0.37), motor dysfunction (p= 0.31), and communication deficits (p= 0.19) as compared with PR patients. In PR patients there is a trend of GHS improvement during therapy (p=0.21), which was not demonstrated in NCR patients (p=0.65). After initiation of treatment for recurrence a significant reduction in QoL was observed for all patients. However, there was a strong tendency toward a better GH in Group A as compared to Group B and C (p= 0.06) and no significant reductions regarding visual disorders, motor dysfunction communication deficits, and symptoms. Conclusion: The primary treatment of GBM patients, including near complete surgical resection and intensive adjuvant therapy does not decrease the QoL, whereas in the recurrent situation despite different treatment regimens a substantial decline in QoL has been demonstrated. P158. IMPROVEMENT OF COGNITIVE FUNCTIONING FOLLOWING SURGERY IN BRAIN TUMOR PATIENTS E. J. J. Habets, R. Walchenbach, A. Kloet, C. J. Vecht, H. Zwinkels, M. J. B. Taphoorn; Medical Centre The Hague, The Hague, The Netherlands Introduction: Many brain tumor patients suffer from impairments in cognitive functioning, which can be caused by the tumor or its treatment. The role of surgery is not well-known; surgical resection may diminish the pressure on healthy brain tissue, but may also harm surrounding neuronal tissue. Purpose: To investigate the effects of craniotomy on the cognitive functioning of brain tumor patients. Patients and Methods: 21 patients (mean age 56.6) with a brain tumor (7 glioblastoma multiforme, 3 low grade glioma, 6 meningeoma, 4 metastases, and 1 pituitary gland tumor) were tested between 1 to 15 days preceding surgery. 12 tumors were located in the dominant hemisphere, 5 in the non-dominant hemisphere, and 4 tumors had another location. The tests were repeated 4 to 104 days after surgery, but before further subsequent therapy was instituted. The neuropsychological test battery took 1 hour to complete and consisted of validated tests for general cognitive functioning, memory, language, perception and visuoconstruction, mental speed, and attention and executive functioning. Results: Of 21 patients included, 18 were tested post-surgery, 1 refused, and 2 others could not be tested due to neurological deterioration (one before surgery due to tumor progression, one following surgery due to stroke). Testing was incomplete in 6 of 18 patients. Compared to normative data, preoperative patients suffered from impairments in language (40%), speed (35%), memory deficits (14%), and executive and perceptual abilities (both 11%). Comparison between pre- and post-surgery test scores revealed no significant differences in general cognitive functioning [Z=–1.84; p=0.07], language performance [t(1.15)=–1.59, p=0.13] or executive functioning [t(1.13)=–0.92, p=0.37]. After surgery, mean mental speed and perceptual abilities were significantly better than before operation [Z=–2.48, p<0.05; Z=–2.22; p<0.05]. Also, there was a trend toward an improvement in memory performance following surgery [Z=–1.85, p= 0.06]. Conclusion: Cognition is not negatively affected by surgical resection of a brain tumor, unless complications occur. Mental speed and perceptual abilities even improved after surgery in our patients. Limitations of the study are its small sample size and the heterogeneity in tumor type. P159. QUALITY OF LIFE IN PATIENTS WITH CEREBRAL GLIOMAS V. Rozumenko, A. Khoroshun, A. Rozumenko; Institute of Neurosurgery, Kiev, Ukraine Background: Evaluation of the treatment efficiency depends on the indexes of quality of life (QL) in oncology patients. QL is the important criterion of the postoperative state of patients with cerebral gliomas (CG). Aim and Methods. The comparative analysis of clinical signs of disease and indexes of QL was conducted in 693 patients with CG before operation and in the postoperative period. Low-grade gliomas (LGG) were found in 143 (20.6%) patients, anaplastic gliomas (AG) were found in 313 (45.2%), and glioblastomas (GBM) in 237 (34.3%) patients. Recovery treatment in the early postoperative period includes pharmacotherapy, physiotherapeutic methods, massage, medical gymnastic, and psychotherapy that depends on neurological disorders and histopathological diagnosis. Results: We defined thirty main parameters which determine the social and adaptation factors of QL and developed the scale of QL. Before the surgical treatment the index of QL was low among patients with LGG in 31.5% cases, among patients with AG in 43.7% and with GBM in 43.5%. As a result of conducted surgical removal of tumor and course of recovery therapy the amount of patients with the low level of QL decreased to 12.6% in LGG group, to 16.6% for AG group and to 22.8% for GBM group. High and middle level increased among patients with LGG from 68.5% to 87.4%, patients with AG from 56.3% to 83.4%, and with GBM from 56.5% to 77.2%. Conclusion: The QL index depends on the histopathological type of glioma: patients with GBM have the lowest index of QL. The combination of surgical and recovery treatment helps to achieve better levels of QL. The QL index is one of informing characteristics of the treatment efficiency in patients with cerebral gliomas. P160. NEUROCOGNITIVE FUNCTIONING IN GLIOBLASTOMA PATIENTS DURING TREATMENT WITH RADIOTHERAPY PLUS CONCOMITANT AND ADJUVANT TEMOZOLOMIDE K. Hilverda1, J. J. Heimans1, I. Bosma1, T. J. Postma1, P. Vandertop2, B. J. Slotman1, J. C. Reijneveld1,3, M. Klein1; 1VU University Medical Center, Amsterdam, The Netherlands, 2Neurosurgical Center, Amsterdam, The Netherlands, 3Academic Medical Center, Amsterdam, The Netherlands Goal: To study neurocognitive functioning in newly diagnosed glioblastoma multiforme (GBM) patients during treatment with radiotherapy (RT) and concomitant and adjuvant temozolomide (TMZ). Methods: Following surgery, cognitive assessment took place at baseline (prior to the start of RT), at first follow-up (after six weeks of RT and concomitant TMZ), and at second follow-up (after three cycles of adjuvant TMZ). Patients with tumor progression during treatment were excluded. At baseline and both follow-ups, patients were compared with healthy controls matched for age, sex, and education. In addition, at baseline and second follow-up, GBM patients undergoing RT+TMZ treatment were compared with historical “pre-Stupp” GBM patient controls treated with conventional RT only. Students t-tests for independent samples and Mann-Whitney U tests were used for comparisons between patient groups and controls, paired t-tests, and Wilcoxon matched pairs tests were performed to determine changes in cognitive functioning during treatment. Results: Analyses were performed in a group of 13 clinically stable RT+TMZ treated patients, and 6 stable RT only patients. Relative to healthy controls, RT+TMZ treated patients displayed impairments in information processing speed (p=0.001), attention (p=0.003), working memory (p=.029), and executive functioning (p=0.000) at baseline. During treatment, functioning remained stable for most cognitive domains. Changes over time were found in two cognitive domains: verbal memory improved (p=0.024) and attentional functioning deteriorated (p=0.026) between first and second follow-up. When compared to RT only patients, RT+TMZ treated patients showed the same cognitive deficits before the start of the treatment. Six to eight months after diagnosis (second follow-up), patients undergoing combined RT+TMZ treatment attained similar or even better neurocognitive levels (e.g., in working memory, p=0.043) than patients undergoing RT only. Conclusion: Prior to the start of RT+TMZ treatment GBM patients showed clear-cut deficits in neurocognitive functioning. In the course of their disease, however, combined treatment with RT and TMZ does not negatively affect neurocognitive functioning in clinically stable GBM patients in most cognitive domains. Although the sample size of RT only GBM patients is rather small, comparisons suggest multimodality RT+TMZ treatment to yield equivalent or maybe even better neurocognitive functioning six to eight months after the start of treatment. P161*. NEUROPSYCHOLOGICAL AND QUALITY OF LIFE FACTORS AS PREDICTORS OF SURVIVAL IN PATIENTS WITH GLIOMA A. Bellver-Pérez1, G. Reynes Muntaner2, B. Espejo Tort3, M. Martín Ureste4, J. Montalar Salcedo5; 1Junta Asociada Provincial de la A.E.C.C. Valencia, Hospital Universitario La Fe, Valencia, Spain, 2Servicio Oncologia Médica, Hospital Universitario La Fe, Valencia, Spain, 3University of Valencia, Valencia, Spain, 4Servicio Oncología Médica, Hospital Universitario La Fe, Valencia, Spain, 5Servicio Oncologia Médica, Hospital Universitario La Fe, Valencia, Spain Introduction and Objectives: In patients with glioma, the neuropsychological impairment may be a result of the tumor itself, or of treatments used to control the disease. The aim of this study is to analyze the predictive survival value of a set of neuropsychological and functional variables in patients with glioma. Materials and Methods: Patients with histological diagnosis of glioma were included in the study. A neuropsychological evaluation of every patient was performed 3 times at 3 month intervals: before starting the post-surgical complementary treatment, 1 month after the completion of radiation and 6 months after the initial assessment. Pts were evaluated with the Karnofsky Performance Status (KPS), the Barthel Index, the Mini-Mental Status Examination (MMSE), the EORTC QLQ-C30 test, the EORTC Brain Cancer Module BN20, and the Hospital Anxiety and Depression Scale (HADS). Statistical analyses: descriptive, multiple regression, and Kaplan-Meier survival analysis were performed. Results: 108 patients were included between January 2002 and December 2006. Average age: 52.6 years (18–77), male: 56%. Histological diagnosis: 69 glioblastoma (GB) (65%), 16 anaplastic astrocytoma (15%) (AA), 7 anaplastic oligodendroglioma (AO) (6%). An 81% of patients were included at initial diagnosis, and 19% at recurrence. Median overall survival was 18.6 months (GB:13.1m; AA:26.7m). Cognitive deterioration (n=29, 27%) was the variable explaining the highest variance in survival (t=3.42, p<0.001), whereas quality of life factors were not statistically significant. The survival average was 9.2 months for pts with cognitive deterioration (CD) at first evaluation, and 25.4 months for patients with good cognitive function. The Barthel Index and KPS had equivalent prognostic significance in terms of survival. Conclusions: Among the variables studied, cognitive deterioration is the most significant factor in prediction of survival. It is important to include quality of life and emotional distress evaluations in the follow-up of patients with glioma, in order to best understand the relationship between medical and psycho-sociological factors. P162. THE USE OF ALTERNATIVE THERAPY IN PATIENTS WITH TUMORS OF GLIAL ORIGIN—A SURVEY OF OVER 600 PATIENTS O. Heese1, M. Schmidt1, S. Nickel2, M. Westphal1; 1Department of Neurosurgery, Hamburg, Germany, 2Department of Social-Medicine, Hamburg, Germany Objective: Despite of multimodal therapeutical approaches the vast majority of glial tumors are not curable. In particular, malignant gliomas tend to reccur fast and reduce survival profoundly. Due to the lack of very effective treatment options patients tend to search for alternative or sublementary therapies in order to fight agains their tumor burden or to relive symptoms induced by their brain tumor and treatments. The amount of alternative therapy use, the patients rational behind it and the cost of alternative therapy for gliomas is not known. We used a questionaire and the database of the german glioma network on order to answer these clinically important questions. Methods: The total number of 621 questionnaires (20 questions asked) were available for evaluation and patients with reference histological confirmed glial tumors from grade 2 to grade 4 were included. These patients were recruted from 6 University Neurooncological Centers. Alternative therapy was defiened as methods or compounds not used in routine clinical practice and not scientifically evaluated. Results: In total 51% of the patients claimed to use alternative therapies. Diverted between the histological grades it was seen that grade II tumors had a rate of 63%, grade III tumors 16% and grade IV tumors 21%. No gender difference was seen. The monthly cost for alternative therapies ranged from 50 to 100 euros. In most of the patients the motivation of alternative therapy use was not driven by unsatisfactory clinical care by the neurooncologists. The motivations came from the wish to add something beneficial to the standard care protocol. Conclusion: In clinical practice patients use of alternative therapies may largeley be overseen and underestimated. Doctors working in the neurooncological field must be aware of this phenomenon and must be open minded in order to treat patients at their best. Critically it has to be mentioned that in this study only patients treated in neurooncological centers were evaluated. The numbers of alternativ therapy use may be underestemated for the whole glioma patient population. P163. STIMULANT DRUG USE IN BRAIN TUMOR PATIENTS: A RETROSPECTIVE SINGLE INSTITUTION REVIEW G. H. J. Stevens, K. Lupica, G. H. Barnett, D. M. Peereboom; Cleveland Clinic Taussig Cancer Center, Cleveland, OH, United States Fatigue is a common complaint of most brain tumor patients independent of tumor type and treatment. A few small series have been published on the use of stimulant medication in primary and metastatic brain tumor patients. Before starting a prospective trial, we retrospectively evaluated our single institution use of Methylphenidate (Ritalin) in 92 adult brain tumor patients over the past 6 years. This was an IRB-approved retrospective chart review. There were 45 females and 47 males. Mean age was 50.3 years. 62 patients had primary brain tumors and 30 patients had metastatic tumors. All patients were started on methylphenidate 10mg a day and the dose was titrated up or down depending on symptoms. We currently have data on 30 patients and the complete data set will be presented at the meeting. The mean methylphenidate dose was 15mg. 77% of patients reported improvement in fatigue and or concentration. 19% reported no clear change on the medication. 4% stopped the medication because they felt worse. One patient had worsening seizure activity thought to be related to methylphenidate use. Methylphenidate appears to be a well tolerated drug to help with fatigue and concentration problems in brain tumor patients and it is probably underutilized in the out-patient department. P164. LATE NEUROCOGNITIVE SEQUELAE IN WHO GRADE I MENINGIOMA PATIENTS M. Dijkstra1, D. van Nieuwenhuizen1, L. J. A. Stalpers2, M. Waagemans1, W. P. Vandertop1,2, J. J. Heimans1, S. Leenstra3, C. M. Dirven4, J. C. Reijneveld1,2, M. Klein1; 1VU University Medical Center, Amsterdam, Netherlands, 2Academic Medical Center (AMC), Amsterdam, Netherlands, 3St. Elisabeth Hospital, Tilburg, Netherlands, 4Erasmus Medical Center, Rotterdam, Netherlands Background: Information on the neurocognitive outcome following treatment of benign meningiomas is virtually lacking. This is remarkable considering these patients' survival is the most favorable of all intracranial tumors. The aim of the present study is therefore to document the extent and nature of neurocognitive deficits in WHO grade I meningioma patients after treatment. Methods: Eighty-nine WHO grade I meningioma patients who underwent surgery with or without adjuvant radiotherapy were individually matched to 89 healthy controls for age, sex, and educational level. Neurocognitive functioning of meningioma patients was assessed at least one year following treatment and compared to that of healthy controls using Student's t-tests. Additionally, associations between tumor characteristics (size and lateralization), treatment characteristics (radiotherapy), and epilepsy burden (based on seizure frequency and antiepileptic drug use) and neurocognitive functioning were investigated by correlational and multiple regression analysis. Results: Compared to healthy controls meningioma patients showed significant impairments in executive functioning (p < 0.001), information processing capacity (p < 0.001), verbal memory (p < 0.001), psychomotor speed (p = 0.001), and working memory (p = 0.006). Regression analyses demonstrated a higher epilepsy burden to be significantly associated with lower executive functioning. Post-hoc analyses indicated these deficits to be specifically related to antiepileptic drug use. No statistically significant associations were established between neurocognitive status and radiotherapy use, tumor localization, or tumor volume. Conclusion: Meningioma patients are characterized by long-term deficits in neurocognitive functioning that can partly be attributed to the use of antiepileptic drugs but not to tumor or radiotherapy-related factors. P166. LATE DAMAGES AFTER CHILDREN'S BRAIN TUMOR TREATMENT M. Pamucka1, L. Czopkiewicz2, W. Jawie3, W. Kosniewski2, P. Tokar2, K. Polednia-Jabłoska2; 1Opole Anticancer Foundation, Opole, Poland, 2Opole Cancer Center, Opole, Poland, 3Medical University, Kraków, Poland 342 children were treated with radio-(RT) and chemotherapy (ChT) at The Cancer Center in Opole in the years 1982–2000 after surgery due to brain tumor. The late damages were estimated in 192 patients (pts) who were living without symptoms of tumor 3 years. We compared the frequency of damages appearing prior to treatment and 3 years after: high intracranial pressure, paresis, epilepsy, ataxia, amblyopy, hormonal and psychiatric problems. Psychophysical retardation, changes in CT/MR and blood vessels damages were described after treatment only. The analysis was conducted depending on the age of pts, durable of anamnesis, tumor location, radicalism of operation, post operative complications, histopathological results, space of RT, ChT sequences. 60 pts had no late damages. We found paresis of facial nerves in case of 2 pts which occurred after operation; ataxia after treatment appeared only in children who had had it before; amblyopy was in 1, hormonal disorders in 32, psychical disorders in 3. The late damages described after treatment only: psychophysical retardation in 82 pts, changes in CT/MR in 41, blood vessels damages in 1. The multivariate analysis showed more radical operation reduces the menace of epilepsy, no confirmation of RT influence, but the influence of ChT is marked. The hormonal disorders appeared most often in pts who were treated because of turkish saddle and central region tumor but there was no evidence of RT influence (p>0.33). Mental disturbances increases with the operation radicalism. The psychophysical retardation increases with the short anamnesis, after the palliative surgery but we did not indicate the influence of RT, the influence of ChT shout be verified on the bigger group. Late damages in CT/MR (I, II of Zimmermann scale) were observed most frequently in the pts treated because of central region and posterior fosse tumors. The biggest number of pts without damages there were in the group: the age 11–18 years, long anamnesis, frontal tumor, radical operation, without perioperative complications, were treated RT on the tumor bed, undergone ChT after RT, untreated with ChT. 71.9 % of pts obtained education. We did not find leukoencephalopathy, necrosis, cerebellar fibrosis. The angiopathy with the subarachnoidal hemorrhage was in 1 pt. The quality of life III, IV grade (own modification of Bloom scale) were observed in 15.1% pts. All relevant factors connected with treatment which (one can assume) provoke origin of brain late damages, are disclosed under threshold symptoms of damages which were to come into being as the result of tumor development and intracranial pressure. These are primary, and factors following the treatment act on the damaged brain regions and increase or reveal earlier under threshold damages. The correlation between the different damages could be the result of the age influence on occurrence of all described damages. P167*. EVALUATION OF LATE TOXICITY IN ADULT PATIENTS TREATED FOR MEDULLOBLASTOMA M. M. Sunyach, C. Christian, F. Didier; Centre Leon Berard, Lyon, France Introduction: Medulloblastoma is a very rare disease in adult population. Standard treatment include craniospinal irradiation (usually 36 Gy). In children risk-adapted radiation dose is employed to reduce the neurotoxicity. Toxicity of cranio-spinal irradiation is not evaluated in adults population. Material and Methods: The records of all patients with medulloblatoma who were irradiated in Centre Léon Bérard from 1978 to 2000 were retrospectively reviewed. Only patient who were free of disease more than 7 years after treatment were included in this study. The regular follow-ups were performed by the neuro-oncology team of Centre Léon Bérard. Twelve patients received serial neurocognitive testing. Results: Thirty-two patients were free of disease 7 years or more after radiotherapy (RT). At last follow-up 5 patients are working with no modification of employement. Three more patients have part-time jobs. Eight patients who were working after RT lost their jobs (5–20 years after RT) because of neurocognitive sequelae, and 2 of them were unable to take care of them at last follow-up. Severe hearing loss occurred in 15/32 patients. Three had second cancer. Among 12 patients who received serial neurocognitive testing median IQ (WAISS III) is 77. Conclusion: High incidence of toxicity suggested that current protocols may require modifications for adults with medulloblastoma. P168*. HADS MOOD SCREENING IN NEURO-ONCOLOGY RADIOTHERAPY PATIENTS N. B. Detert1, C. Blesing2, N. Warner2, V. Russell1; 1John Radcliffe Hospital, Oxford, United Kingdom, 2Churchill Hospital, Oxford, United Kingdom Background: Previous investigations of depression and anxiety in cancer patients demonstrate significantly raised rates of affective disorder, associated with reduced quality of life. Patients in busy neuro-oncology clinics do not always raise emotional issues, but treatment for mood disorders can significantly improve quality of life. Screening for affective disorders is an often-recommended strategy to address this. The Hospital Anxiety and Depression Scale (HADS) is a well-validated questionnaire measure with good psychometric properties, which is quick to complete and score, and easily tolerated. Aims: This study assesses the utility of HADS screening in comparison with assessment-as-usual. We also document the prevalence of HADS and Clinician-rated mood disorder in our sample, and examine the association of tumor location, grade, functional status and past psychiatric history with mood. Method: Consecutive consenting neuro-oncology radiotherapy patients completed the HADS, and clinicians completed a data-sheet, documenting clinician-ratings of mood and other clinical variables at first clinic, midradiotherapy and follow-up. Tumor location was checked on radiology reports. Results: Results are reported of the first 44 patients recruited at first clinic. The HADS categorized significantly more patients with affective disorder (anxiety and/or depression) than clinician categorization (p<0.05). HADS-rated prevalence of affective disorder was 27% (clinician-rated, 11%; HADS or clinician combined, 34%). There was a significant association between affective disorder and bilateral tumors (p<0.05), though numbers were small. There was no significant group difference on mean Karnofsky Performance Scale scores between groups with and without affective disorder. No significant association was found of affective disorder with tumor grade (high/low), past mood disorder, or cognitive impairment but numbers were small. Available data at mid-radiotherapy and follow-up are also reported. Conclusions: The HADS was significantly more sensitive to affective disorder than assessment-as-usual in our study, supporting the usefulness of routine mood-screening. 27–34% of our patients suffered clinically significant affective symptoms, consistent with previous studies. There is evidence that patients with bilateral tumors may be at greater risk of affective disorder. P169. COGNITIVE FUNCTION IN WOMEN WITH BREAST CANCER AFTER CHEMOTHERAPY TREATMENT M. Matijasevic1, J. Arsenijevic2, S. Milosevic1, Z. Ždrale1, Z. Tomasevic1; 1National Institute for Oncology and Radiology Serbia, Belgrade, Serbia and Montenegro, 2Hospital Nova Vita, Belgrade, Serbia and Montenegro Introduction: Applying chemotherapy in patients with breast cancer can make impairment in some of quality of life dimension. Previous clinical experience demonstrated that chemotherapy could lead to long term or instant impairment of some cognitive function. Clinical study did not approve unique attitude according this experience. Mostly vulnerable are executive function. We would like to examine cognitive function in patients who have already received chemotherapy. Methods: 42 patients with breast cancer after receiving chemotherapy set a 2 test-TMT-A which measures attention and TMT-B which measures executive function. These results are compared with results of referent subgroup for their population. Patients were not equal in age and all were women. The highest subgroup was aged between 40–49 years old, the before-menopause group. Results: Results in first tests TMT-A which measure attention was in average level according to normal population or less then average. Results on second test TMT-B which measure executive function were on high level according to normal populatation, 7 (16.7%) patients demonstrated high level results compared to normal population. Conclusion: The largest subgroup showed best results as expected. Low score on TMT-A could be explained in view of setting—patients completed the tests while they waited for ambulatory examination, so they were excited to hear the state of their health condition. Therefore, in a small population in this pilot study we saw good results in TMT-B, which means without impairment in executive function. But we cannot make a conclusion, only provide a direction for future larger controlled and randomized clinical studies. P170. A SPECIALIST NURSE AS A RESOURCE FOR FAMILY MEMBERS TO PATIENTS WITH BRAIN TUMORS A. Spetz1, R. Henriksson1, P. Salander2; 1Dept of Radiation Sciences, Oncology, Umea University, Umea, Sweden, 2Dept of Social Work, Umea University, Umea, Sweden There are few scientific publications available with the focus on the value of supportive care service for patient with brain tumors and their families. The present study is part of a project where a specialist nurse (SN) function was implemented for patients with mailgnant glioma and their next-of-kin. The purpose of the present study was to identify how next-of-kin made use of the SN function. To identify what they asked for when they contacted the nurse is a way of understanding the vulnerability of family members' and thus to learn how to provide better support to the benefit of the family. In accordance to a design inspired by action research, the SN approached patients and next-to-kin during diagnosis at the Departments of Oncology and Neurosurgery and informed them that they could use the SN as a resouce when they wanted. The SN documented all contacts with the next-of-kin of 16 consecutive patients in field notes during the course of the disease: telephone calls and personal meetings—who contacted whom, about what, and with what outcome. In addition summarizing interviews were conducted. The study is based on field notes and complemented with the interview data. Different needs were expressed throughout the relationship between the next-of-kin and the SN: initially, conversation about the sick family member was paramount; but as the time passed, talk about oneself came to the forefront, and thereafter, they also commented on the relationship to the SN in a more personal tone. The relationship to the SN per se is important—the SN function can be far more than a provider of information. All together, the platform provided by the SN easily lends itself to the conceptualization of “a secure base” in attachment theory. P171*. PHASE II STUDY OF FIXED-DOSE RATE (FDR) GEMCITABINE AS A RADIOSENSITIZER FOR NEWLY DIAGNOSED GLIOBLASTOMA MULTIFORME (GBM) A. Fabi, A. M. Mirri, G. Metro, A. Felici, A. Vidiri, A. Pace, M. A. Carosi, F. Cognetti, E. M. Occhipinti, C. M. Carapella; Regina Elena National Cancer Institute, Rome, Italy Background: In a previous phase I study (J Neuro-Oncol, 2008), where FDR Gemcitabine at 10 mg/m2/min was tested in association with radiotherapy (RT) for the treatment of newly diagnosed GBM, a maximum tolerated dose of 175 mg/m2/wk was identified. Methods: After surgery for GBM (either microsurgical removal or stereotactic biopsy), patients were treated with fractionated focal RT at a daily dose of 2.0 Gy per fraction, five days per week for six weeks (total dose of 60 Gy). FDR Gemcitabine at 175 mg/m2/wk was concomitantly given starting 24–72 hours prior to RT, and then for the whole duration of radiation treatment. An MRI performed at 7 and 40 days from the end of chemoradiotherapy was used for activity assessment. Standard oral temozolomide 150–200 mg/m2 was administrated following the combined treatment. Results: From 03/2005 21 patients (10 male, 11 female) have been enrolled. Characteristics of patients were: median age 57 years (42–72), median KPS at baseline 90 (70–100), surgery/stereotactic biopsy 17/4. Median time from diagnosis to the initiation of Gemcitabine was 44 days (28–54). Among the 20 evaluable patients (one too early) 4 (20%) partial responses, 11 (55%) stable diseases, and 7 (35%) progressive diseases were recorded. At a median follow up of 22 months (2–33) we observed 5.8 months (1.5–24) as time to tumor progression. Toxicity was manageable with only one G3 neutropenia and hypertransaminasemia in two patients respectively. Grade 1 hypertransaminasemia was registered in 6 patients (43%). Conclusions: These preliminary results show that in patients with newly diagnosed GBM, radiosensitizing FDR Gemcitabine at 175 mg/m2/wk is a well-tolerated regimen with an interesting activity. Accrual is ongoing and final results will be presented at the meeting. P172*. A PHASE 2 STUDY OF MULTIMODAL THERAPY WITH SURGERY, CARMUSTINE (BCNU) WAFER, RADIATION THERAPY (RT), AND TEMOZOLOMIDE (TMZ) IN PATIENTS (PTS) WITH NEWLY DIAGNOSED SUPRATENTORIAL MALIGNANT GLIOMA (MG) R. La Rocca1, T. W. Vitaz2, W. Villanueva3, J. Hodes4, A. Cervera1, P. New5, N. Litofsky6, N. Litofsky6; 1Kentuckiana Cancer Institute, Louisville, KY, United States, 2Neurosurgical Institute of Kentucky, Louisville, KY, United States, 3Louisville Neurological Surgeons, Louisville, KY, United States, 4Neurosurgical Associates, Louisville, KY, United States, 5Baylor College of Medicine, Houston, TX, United States, 6University of Missouri University Hospital, Columbia, MO, United States Background: Previous studies in initial MG demonstrated the efficacy of both BCNU wafer (Gliadel) and TMZ (Temodar) as part of multimodal therapy with resection and RT. This phase 2 trial assessed the safety and efficacy of using both BCNU wafer and TMZ within a multimodal regimen. Methods: Eligible pts were aged 18–72 yrs with resectable, initial MG. After resection and BCNU wafer insertion, pts received concomitant daily RT 2 Gy (total ⩽60 Gy) + TMZ 75 mg/m2 (⩽45 days) followed by monthly TMZ (200 mg/m2 daily for 5 of every 28 days, ⩽18 cycles). Endpoints included median survival (MS) and progression-free survival (PFS), which were analyzed by RTOG recursive partitioning analysis (RPA) and methylation status of the O6-methylguanine-DNA methyltransferase (MGMT) promoter. Results: A total of 41 pts entered the study. Final pathology included glioblastoma (n=40) and anaplastic astrocytoma (n=1). At baseline, median (range) age was 59 yrs (29–81), and median KPS was 90 (60–100); 9, 21, and 11 pts were RPA class III, IV, and V, respectively; 26 pts had adequate tissue for MGMT analysis (methylated n=8; unmethylated n=18). Median follow-up was 36.2 mos; 32 pts experienced recurrence; 27 pts died. MS was 19.7 mos, and median PFS was 7.2 mos. The 12- and 24-month survival rates were 65% and 31%, respectively. The 6- and 12-month PFS rates were 58% and 27%, respectively. MS was 19.7 mos for unmethylated MGMT and 23.3 mos for methylated MGMT; median PFS was 7.2 and 11.1 mos, respectively. Six pts (14.6%) remain progression-free at 2+ yrs (range 25.5–48.7 mos): 3 pts had methylated MGMT and 3 pts had inadequate tissue. MS was not reached for RPA class III pts and was 18.6 and 10.9 mos for class IV and V pts, respectively (P=0.01). Adverse events included deep vein thrombosis (n=8), pulmonary embolism (n=4), sterile brain abscess (n=1), pneumonia (n=2), and aplastic anemia (n=1). Cause of death included disease progression (n=25), brain hemorrhage following fall (n=1), and pulmonary embolus (n=1). Conclusion: These data suggest that multimodal therapy with BCNU wafer followed by RT/TMZ is an effective regimen in pts with initial MG. Survival results compare favorably with historical survival data of BCNU wafer, TMZ, and RPA class. Adverse events observed in this trial were similar to historical MG data. Randomized trials are needed to assess efficacy of this regimen compared with RT/TMZ alone. P173. SAFETY AND FEASIBILITY OF THE ADJUNCT OF LOCAL CHEMOTHERAPY WITH BIODEGRADABLE CARMUSTINE (BCNU) WAFERS TO THE STANDARD MULTIMODAL APPROACH TO HIGH-GRADE GLIOMAS AT FIRST DIAGNOSIS M. Salvati1, C. Brogna1, A. d`Elia1, A. Melone1, J. Lenzi1, A. Frati1, M. Rojas2, A. Santoro1, F. Giangaspero1,3, R. Delfini1; 1Neuroscience-Neurosurgery Department, Sapienza University, Rome, Italy, 2Neuroradiology D.E.A. Sapienza University, Rome, Italy, 3Neurosurgery Department, INM Neuromed IRCCS, Pozzilli, Isernia, Italy Background: The aim of this retrospective study is to determine the safety and feasibility of the combined treatment with surgery and intraoperative placement of carmustina 7.7 mg wafers (Gliadel), followed by standard adjuvant treatment with radiotherapy and concomitant and subsequent chemotherapy with temozolomide (TMZ), for supratentorial high-grade gliomas at first diagnosis. Materials and Methods: In the period between February 2006 and January 2008, 32 patients were treated at our institution for cerebral supratentorial high-grade glioma with surgery and intraoperative placement of wafers of carmustine (Gliadel). No postsurgical complications could be observed. After a median time of 4.8 weeks (range: 3–6 weeks), all patients began adjuvant treatment with concomitant radiotherapy with a mean of 60 Gy and temozolomide (TMZ) chemotherapy with 75 mg/m2 during which weekly hematologic assessments were routinely performed. After 3 to 6 weeks patients commenced adjuvant TMZ regimen, administered 5 days every 28, 200 mg/m2 for a programmed number of cycles that was of not less than 12. A contrast-enhanced MRI was routinely performed. Median follow-up after surgery was of 6.5 months, ranging from 4 to 23 months. Results: The mean presurgical KPS was of 80 (range: from 60 to 100), and it remained unmodified after adjuvant therapies even at suspension of steroids administration. In 4 cases there was a radiologic evidence of progression of the disease and the necessity of steroids, with a progression-free survival (PFS) of 6, 8, 9.5, and 13.6 months. One case died 14 months after first operation. All other patients are still alive. Conclusions: The integration of local chemiotherapy with carmustine wafers and the standard adjuvant regimen with radiotherapy and concomitant chemiotherapy appears to be safe and feasible, without any adjunctive complication. P174. RADIOTHERAPY AND ADJUVANT TEMOZOLOMIDE COMPARED WITH RADIOTHERAPY AND CONCOMITANT PLUS ADJUVANT TEMOZOLOMIDE IN SURGICALLY TREATED PATIENTS WITH GLIOBLASTOMA MULTIFORME: A RETROSPECTIVE SINGLE INSTITUTION STUDY M. Goeppert1, J. Felsberg2, W. Stummer1, G. Reifenberger2, H. Steiger1, M. Sabel1; 1Department of Neurosurgery, Duesseldorf, Germany, 2Department of Neuropathology, Duesseldorf, Germany Objective: The benefit of the introduction of alkylating chemotherapy in treatment of glioblastoma multiforme (GBM) patients has recently been demonstrated by comparing radiotherapy with concomitant plus adjuvant temozolomide to radiation therapy alone (Stupp et al., 2005). The impact of the concomitant part of this protocol on survival remains unclear. We therefore retrospectively compared patients treated with surgery followed by radiotherapy and adjuvant temozolomide (TMZ) (group A) with the concomitant plus adjuvant (Stupp) protocol (group B) regarding overall survival (OS) and progression-free survival (PFS). Methods: We included 70 patients with primary GBM treated in our institution between 2002 and 2007 by open resection, radiotherapy and at least 2 cycles of TMZ. Patients were stratified for extent of resection (partial [PR] vs. complete [CR]), MGMT promoter methylation and postoperative tumor volume estimated by MRI. A total of 3 patients in group A (n=35) and 19 patients in group B (n=35) were censored. Results: Both groups were balanced for established prognostic factors like age (median: 58y), pre-operative Karnofsky performance score (median 80%) and MGMT promoter methylation status. However, the groups differed in the extent of resection (group A: 13 CR/22 PR versus group B 21CR/14PR). OS and PFS were 16.6m / 5.0m for group A and 20.7m / 6.0m for group B (p=0.352). MGMT non-methylated patients (group A: n=19, group B, n= 20) demonstrated an OS of 16.3m vs. 15.4m (p=0.543). MGMT methylated patients (group A, n=15, group B, n=11) demonstrated an OS of 20.7m vs. 20.0m (p=0.926). Regardless of the treatment, MGMT methylation was associated with longer OS (MGMT non-methylated vs. MGMT methylated 16.2m/20.7m, p<0.015). Conclusions: At present, due to the high number of censored patients in group B, a final conclusion can not be drawn regarding the comparison between the concomitant plus adjuvant versus the adjuvant protocol. However, as yet there is no difference between both treatment protocols regarding OS and PFS. MGMT hypermethylation is associated with longer survival in both treatment groups. P175. LONG TERM TEMOZOLOMIDE TREATMENT FOR MALIGNANT GLIOMA H. C. Bock1, J. Hinz2, S. Kantelhardt1, V. Rohde1, A. Giese1; 1Department of Neurosurgery, Göttingen, Germany, 2Department of Anesthesiology, Emergency and Intensive Care, Göttingen, Germany Objective: Therapeutic options for patients with first diagnosed and recurrent malignant glioma concentrate on surgical resection and radiotherapy currently combined or followed by temozolomide treatment. Although the prognosis is still poor and many patients do not even complete the standard therapy of 6 cycles, a selected patient population remains in a stable enough clinical condition to continue this regimen beyond 6 cycles. Patients and Methods: Using our institutional glioma database we have identified 22 patients who received more than 10 cycles 5/28 days schedule temozolomide therapy (range: 10 to 75 cycles). Those patients who received high cycle temozolomide treatment were treated first line, with concomitant radiation therapy, or second line after previous PCV or ACNU chemotherapy. The patient population was analyzed with respect to delays in therapy protocols or changes in chemotherapy modalities and for progression free intervals and survival. Results: In a patient collective of 210 patients with first diagnosed malignant glioma, 151 received a temozolomide 5/28 days schedule, as recommended by EORTC, at any time during their oncological treatment. 15% of these received 10 or more cycles. For these patients we found a survival range between 17 and 96 months. Patients who died had a mean survival of 30 ± 14.8 months, for those still alive the median follow up was 40.8 ± 23.8 months. 55% received concomitant radiochemotherapy first line. 23% started with temozolomide after radiation. In 9% ACNU and in 5% PCV chemotherapy was carried out first line, before temozolomide treatment was initiated and maintained. 41% underwent second surgery because of tumor recurrence and 89% of these patients subsequently carried on temozolomide treatment with 5/28 or 21/28 days schedules. In 27% of patients following second surgery because of tumor recurrence, the second line temozolomide treatment resulted in a significantly longer radiographic progression free interval compared to first line temozolomide treatment. Conclusion: Our study demonstrates that high cycle temozolomide as first line or second line treatment resulted in stable disease over prolonged periods of time. Surprisingly, following progression second line temozolomide again resulted in tumor control exceeding the interval of initial response. Our data suggest that temozolomide may actually be given for well over 10 cycles even following progression and second surgery. P176. FIRST RESULTS OF THE CONCOMITANT PROTOCOL IN NEWLY DIAGNOSED GLIOBLASTOMA AND COMPARISON TO ALTERNATIVE PROTOCOL M. Caroli1, R. Campanella1, C. Menghetti1, S. Zella1, S. Borsa1, F. Costa2, A. De Santis2, M. Fornari2, S. Gaini1; 1Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Fondazione IRCCS, Milano, Italy, 2Istituto Ortopedico Galeazzi IRCCS, Milano, Italy Actually, the standard treatment of newly diagnosed GBM is surgery or biopsy and concomitant chemo-radiotherapy with temozolomide (Stupp protocol) followed by monthly adjuvant cycles of chemotherapy. In the past years we have proposed a personal neoadjuvant modified protocol with temozolomide, followed by standard radiotherapy and, after that, monthly adjuvant cycles of temozolomide until recurrence and the results in terms of TTP and overall survival, were quite similar to the results of concomitant therapy. Considering that many people are not able to be submitted to a true concomitant scheme for different reasons (age > 70, Karnofsky less than 70, rehabilitation program that should delay the start of radiotherapy) we decided to adopt our personal modified scheme in all the cases in which concomitant therapy was not available. For these reasons in the last three years we addressed patients with KPS of 70 or more, younger than 70 to concomitant therapy, while the other patients received our modified protocol. We present two groups: one of 27 selected patients submitted to concomitant therapy from 2004 to 2006, ranging from 32 to 69 years (median age 59) and the second made up by 37 patients from 32 to 76 years (median age 66) treated with the alternative scheme. All patients were submitted to surgical removal of the tumor, except for 6 patients who were submitted only to stereotactic biopsy (3 patients in each group). In the group of concomitant therapy, one patient (a 69 year old woman) discontinued the treatment because of the onset of severe neurological and cognitive deterioration and another patient (50 year old male) experienced bronchopneumonia and delayed the adjuvant cycles. Another patient (65 year old man) suffered a severe thrombocytopenia and required transfusion. The preliminary results showed a median TTP of 10 months in the group of alternative protocol and a median TTP of 13 months in the group of concomitant therapy. One third of the patients in the concomitant group are still alive at 24 months. Furhermore, the patients belonging to this group had a median KPS of 70 at time of recurrence and a median MMSE of 24, 10 of them received second surgery (in one case intra-operative BCNU wafers were positioned), and 7 cases were submitted to second line chemotherapy with fotoemustine. Longer follow-up is required, but we can affirm that an acceptable quality of life has been maintained in both group, with a similar median MMSE at one year (median score=24). P177. A CONCURRENT COMBINATION OF RADIATION THERAPY-FOTEMUSTINE FOR NEWLY DIAGNOSED MALIGNANT GLIOMAS, A PHASE II STUDY P. D. Beauchesne1, C. Carnin1, V. Bernier2, L. Taillandier1; 1Hôpital Central, Nancy, France, 2Centre a Vautrin, Vandoeuvre les nancy, France Purpose: Fotemustine, a nitrosourea compound, is used for the treatment of malignant gliomas, especially in France. Recently, EORTC-NCI Canada has shown that a concomitant combination of radiation therapy-temozolomide (oral cytotoxic drug) improves survival in glioblastomas. We are testing a concurrent combination of fotemustine and radiotherapy for newly malignant gliomas. Methods: A prospective phase II study has opened for accrual in September 2004. Patients over 18 years of age who are able to give informed consent and have histologically proven, newly diagnosed supratentorial malignant gliomas are eligible. All patients were treated by a standard cranial irradiation (conformal irradiation, tumor bulk plus a margin of 2.5 cm) and concomitant daily administration of 10 mg/m2 of fotemustine (5 days per week, 6 weeks, 1 hour 30 before radiation therapy). Adjuvant chemotherapy was administered at tumor progression, fotemustine as one intravenous injection (100 mg/m2) each 28 days for 6 cycles. Results: To date 22 patients have been enrolled in this study, 16 men and 6 women, median age 57 (range 32 to 74), and median Karnofsky performance status 70 (range from 60 to 100). Histology included 16 glioblastomas, 3 anaplastic astrocytomas, 2 anaplastic oligodendrogliomas, and 1 mixed glioma. Surgery (3 total resections) was performed for 9 patients and stereotactic biopsy for 13 patients. This concurrent association of radiation therapy and fotemustine has been well tolerated. The toxicity was mild; one hematologic toxicity as grade III-IV has been observed. Median survival from initial diagnosis was 10 months, and one patient remains alive. Median survival was 11.9 months for surgery and 9.2 months for stereotactic biopsy. Conclusions: Concomitant combination fotemustine and radiation therapy is safe and well tolerated. Overall survival of over 10 months for all population compares favorably with other reports. Updated definitive results will be presented at the meeting. P178*. PHASE I TRIAL OF ARSENIC TRIOXIDE AND TEMOZOLOMIDE IN COMBINATION WITH RADIATION THERAPY FOR PATIENTS WITH HIGH-GRADE GLIOMAS S. A. Grimm1, M. Marymont1, J. Chandler1, K. Muro1, S. Newman1, R. Levy1, L. Rice2, K. Burns2, C. Cabreza2, J. Raizer1; 1Northwestern University, Feinberg School of Medicine, Chicago, IL, United States, 2Northwestern Medical Faculty Foundation, Chicago, IL, United States Background: Arsenic Trioxide (ATO) is an inorganic metal that is FDA approved for the treatment of relapsed or refractory acute promyelocytic leukemia. At low doses, it causes G2/M arrest and cell death in glioma cell lines and is synergistic with radiotherapy in animal models. The objective of this study was to determine the maximum tolerated dose (MTD) and safety of ATO in combination with temozolomide (TMZ) and radiotherapy (RT). Methods: A standard 3+3 dose escalation study with 3 pre-determined dose levels was performed to determine MTD and dose-limiting toxicity (DLT). Patients with newly diagnosed glioblastoma multiforme (GBM), anaplastic astrocytoma (AA), or anaplastic oligoastrocytoma (AOA) were eligible. Intravenous ATO was administered 1–2 hours prior to RT daily for 5 days during the first week, then twice weekly from week 2 until the completion of RT. TMZ was administered daily for 42 days. The dose levels were: (1) TMZ 60 mg/m2/ATO 0.2 mg/kg; (2) TMZ 75 mg/m2/ATO 0.2 mg/kg; (3) TMZ 75 mg/m2/ATO 0.25 mg/kg. All received concurrent external beam RT 5940-6120 cGy in 28/33 fractions. All patients received up to 12 cycles of adjuvant TMZ 200 mg/m2 on a 5/28 day schedule beginning 3 weeks after the completing RT. DLT was determined by toxicity measurements using NCI CTCAE v3 from enrollment until the start of adjuvant TMZ. Results: 17 patients (13 GBM, 2 AA, 2 AOA) were accrued. 65% were men. The median age at diagnosis was 52 (range 25–80). Median KPS was 90% (range 70–100%). Dose level 1 included 2 additional patients for optimal assessment of toxicity because 2 did not receive TMZ as specified (only 5 days per week instead of 7). One patient at dose level 2 missed two doses of ATO for grade 4 transaminase elevation. One DLT occurred at dose level 2 (grade 4 transaminase elevation) and 2 DLT's occurred at dose level 3 (grade 4 neutropenia and grade 3 QTc prolongation). Grade 3 toxicities included leukopenia (2), thrombocytopenia (2), anemia (1), and QTc prolongation (1). Grade 4 toxicities included leukopenia (1) and liver transaminase elevation (1). MTD was ATO 0.20 mg/kg and temozolomide 75 mg/m2. Conclusions: ATO in combination with TMZ and RT is safe and well tolerated at the MTD of ATO 0.20 mg/kg and temozolomide 75 mg/m2. Further studies at the MTD are warranted to determine the efficacy of ATO in malignant gliomas. P179. EFFICACY ANALYSIS OF CONVECTION ENHANCED DELIVERY OF PRX321 IN GBM (NBI-3001-9002, 9003, 0001) F. W. Weber1, F. W. Floeth2, A. Asher3, M. Westphal4, N. Merchant5; 1Kliniken Koeln gGmbH, Cologne, Germany, 2HHU Duesseldorf, Duesseldorf, Germany, 3Carolina Neurosurgery and Spine Associates, Charlotte, NC, United States, 4University Hamburg, Hamburg, Germany, 5Protox Therapeutics Inc., Vancouver, BC, Canada Clinical results of two early phase clinical studies of PRX-321 conducted in the USA and Europe were pooled to identify possible paths in the clinical development of PRX-321 in recurrent GBM. Both studies were small in size 31 and 32 patients. Patients were treated with 90–900 microgram (concentration range 1.5–15 microgram/mL and volume range: 40–100 mL). The phase 2 study used lower study drug concentrations 1.5–6 microgram/mL (compared with 6–15 microgram/mL in the phase 1 study) hence lower total exposure of 90–300microgram (compared with 240–900 microgram in the phase 1 study). In addition to the lower concentration / exposure, patients in the phase 2 study had lower pre-treatment Karnofsky score, included more females and introduced tumor resection 4 weeks post treatment. All these factors were expected to have some effecton survival. Overall median survival of all GBM patients was 210 days with the phase 1 study having a somewhat higher median survival of 268 days vs. 199 days for the phase 2 study. Prognostic and treatment parameters evaluated for possible effect on patient survival included: age, gender, KS-baseline, months from diagnosis, number of catheters, study drug exposure (concentration, volume), and tumor-volume-adjusted study drug exposure. Future studies have to address the question of optimal concentration and volume combination. Very important is to reduce variability between patients and between sites. P180. BRAIN TUMOR TREATMENT RESULTS WITH THE USE OF POLYMER FORM OF METHOTREXATE FOR LOCAL CHEMOTHERAPY L. R. Harutyunyan1, H. M. Galstyan1, V. H. Matosyan2, G. K. Jamakochyan1; 1National Center of Oncology of RA, Yerevan, Armenia, 2Nairit CJSC, Yerevan, Armenia According to the general statistics, intracerebral tumors or gliomas occurs in more than 50% of tumors of the central nervous system. Contemporary neurooncology permits positive treatment results by using complex approaches including surgery, radiotherapy, chemotherapy, and immunocorrection. However, the role of adjuvant chemotherapy is not completely determined and results are controversial. The results can be improved, if adjuvant chemotherapy delivers cytotoxic agents to the tumor, partially resected or bed of completely resected, in a direct targeted way, avoiding blood-brain barrier. Our study presents results of the local chemotherapy fresh method testing, aimed at optimal delivery of chemotherapeutic agents by polymer film for intracerebral tumor treatment. The polymer film is a three layer chemotherapy containing calculated dose of cytotoxic (methotrexate), which becomes a store of cytotoxic for a long term impact only on the damaged cerebral tissues, without spreading it on the healthy regions of the brain. Two phases research, in vitro and in vivo on experimental animals (rats), had been carried out. The research proved that the best results are achieved by polymer film containing methotrexate. The successful outcome was presented to the ethical committee and scientists council of the National Center of Oncology of the Republic of Armenia, which permitted the further use of the means on human beings. Totally 58 patients treatments with brain tumors (gliomas) were analyzed; 29 patients received complex treatment (including surgery with implantation of methotrexate containing film and radiotherapy), and the rest received combined treatment (surgery and radiotherapy). The follow-up study showed that the method of complex treatment with use of local chemotherapy containing methotrexate has satisfactory tolerance by patients, without side effects, and increased survival rate of patients comparing with control group. P181. TARGETING OF MALIGNANT GLIOMAS WITH [BI-213]-LABELLED SUBSTANCE P—THE “ALPHA KNIFE” EXPERIENCE D. Cordier1, F. Forrer2, S. Kneifel2, J. Müller-Brand2, H. Mäcke2, A. Merlo3; 1Division of Neurosurgery, University Hospital, Basel, Switzerland, 2Dep. of Nuclear Medicine, University Hospital Basel, Switzerland, 3Division of Neurosurgery, University Hospital Basel, Switzerland Objective: Local radiopeptide therapy using radiolabelled substance P specifically targets NK1-receptors, which are consistently overexpressed in malignant gliomas. Using beta-particles emitting [Yttrium-90]-DOTAGA substance P we have recently shown the feasibility and low toxicity of this approach. However, in critically located tumors, the mean tissue range of 5 mm of Yttrium-90 may lead to unacceptable damage of adjacent, functional critical areas of the brain. In contrast, the alpha-emitting radionuclide Bismuth-213 has only a mean tissue range of 0.08 mm. Currently, we evaluate radiopeptide therapy using [Bi-213]-DOTAGA substance P in patients with critically located high- and low-grade gliomas. Methods: In a pilot study, we included patients with functionally critical located high (n=3) or low grade (n=3) gliomas without previous treatment. After implantation of intratumoral catheter systems, 1–3 local injections with Bismuth-213 labeled substance P are performed. The analogous methodology has been published previously (Clin Cancer Res 2006 12:3843–50). Besides feasibility and toxicity, endpoints of the study are progression free survival and overall survival. Results: Targeted radiopeptide therapy using [Bi-213]-DOTAGA substance P was well tolerated by all patients included so far. Repetitive imaging is highly suggestive of progressive radiation-induced necrosis, which is confirmed by postoperative histopathological examination. At surgery, tumors pretreated by this method exhibit a pseudocapsular demarcation, which significantly facilitates the resection. Conclusions: Targeted loco-regional radiotherapy using [Bi-213]-DOTAGA substance P may represent an innovative and effective treatment strategy for functionally critical located malignant gliomas. Primarily nonoperable gliomas may become resectable in the course of this treatment, thereby possibly significantly improving the prognosis. P182. INCREASED DIAGNOSTIC YIELD OBTAINED BY MRI/PET FUSION IMAGE FOR RECURRENT GLIOMA: USEFULNESS OF 3′-DEOXY-3′-[18F] FLUOROTHYMIDINE(FLT) M. Okada1, T. Hatakeyama1, D. Ogawa1, S. Ookubo1, K. Miyake1, N. Kawai1, T. Tamiya1, Y. Yamamoto2, Y. Nishiyama2; 1Department of Neurological Surgery, Faculty of Medicine, Kagawa University, Kagawa, Japan, 2Department of Radiology, Faculty of Medicine, Kagawa University, Kagawa, Japan A FLT, 3′-deoxy-3′-[18F]fluoro-thymidine is an imaging agent for positron emission tomography (PET) designed to visualize increased DNA synthesis. Therefore, the signal level of FLT-PET is supposed to reflect tumor proliferation, and accordingly it may predict histological malignancy. We report a case with recurrent diffuse astrocytoma, which was exposed by kinetic analysis of FLT-PET and histologically confirmed by surgery under the guidance of MRI/FLT-PET fusion image. The case was a 49-year-old left-handed woman with diffuse astrocytoma of her right frontal lobe. As the tumor adjacent to her motor area and language center, tumor was partially resected. Histological diagnosis was gemistocytic astrocytoma. Three months after extended focal brain irradiation of 60 Gy, expanding enhancement of residual tumor on MRI appealed local recurrence of tumor or radiation necrosis. 11C-methionine PET demonstrated decreased accumulation, however, the kinetic analysis of FLT-PET revealed increased metabolism of FLT, which implied malignant transformation of the tumor. Images from FLT-PET were superimposed over MRI image to make surgical plan for diagnostic resection. Thus, selective open biopsy of the tumor without surgical morbidity was performed under the guidance of MRI/FLT-PET fusion image. Tissue specimen taken from the site of increased k3 value on FLT-PET disclosed the tumor expressed potential malignant features; increased cell density, nuclear pleomorphism, bizarre cells with giant nuclei, the elevation of Ki-67 labeling index and p53 overexpression. These features were concomitant with radiation necrosis. We reason that MRI/FLT-PET fusion image can be helpful in distinguishing possible malignant transformation of diffuse astrocytoma on its early stage. It also would be useful tool for surgical planning to increase diagnostic yield of biopsy from recurrent glioma after irradiation. P183*. MGMT IMMUNOEXPRESSION IN PROGRESSIVE NONFUNCTIONING PITUITARY ADENOMAS: POTENTIAL CANDIDATES FOR TREATMENT WITH TEMOZOLOMIDE? G. Widhalm1, S. Wolfsberger1, M. Preusser2, A. Wöhrer3, M. Kotter1, T. Czech1, C. Marosi2, E. Knosp1; 1Department of Neurosurgery, Vienna, Austria, 2Department of Internal Medicine, Vienna, Austria, 3Institute of Neurology, Vienna, Austria Objective: In progressive non-functioning pituitary adenomas (NFPA) with resistance to conventional treatment, effective alternative therapy regimes are warranted. Temozolomide (TMZ) was reported as a new approach in pituitary carcinomas and aggressive pituitary adenomas. MGMT immunoexpression dependent responsiveness of TMZ in pituitary tumors was recently suspected. The aim of the present study was to analyze for the first time the MGMT immunoexpression in a series of patients with progressive NFPAs to evaluate if TMZ might be an alternative treatment option. Methods: We studied a cohort of 45 patients with non-functioning adenomas. Based on postoperative MRI follow-up, patients were divided in a progressive group (n=24) and tumor-free group (n=21). MGMT immunoexpression was assessed in tumor specimens of all patients, and statistical comparisons of MGMT expression of the two tumor subgroups were performed. MGMT immunoexpression of all 45 patients after primary surgery showed low MGMT expression in 17 patients (38%) and high MGMT expression in 28 patients (62%). Low MGMT expression was present in five of 21 patients (24%) in the tumor-free group as compared to 12 of 24 patients (50%) in the progressive group after first operation. Comparable MGMT expression was detected also in repeated surgeries. A shorter interval to second surgery was found in patients with low MGMT expression (log rank p=0.057). Conclusions: Our first series demonstrates that half of patients with progressive, regrowing NFPAs with low MGMT expression are potential candidates for treatment with TMZ. Therefore, TMZ provides a rationale as alternative treatment approach in these patients in case of resistance to conventional therapy (e.g. re-operation/radiosurgery/radiotherapy). P184. MGMT PROMOTER METHYLATION STATUS IN NEWLY DIAGNOSED GLIOBLASTOMAS (GBM): RETROSPECTIVE ANALYSIS FROM A CLINICAL SERIES OF PATIENTS M. Martinez Garcia1, A. Tortosa2, X. Maldonado3, S. Gonzalez4, C. Balaña5, O. Gallego6, E. Verger7, R. Fuentes8, V. Navarro1, M. Gil Gil1; 1Instituto Catalan de Oncologia (H. Duran y Reynals), L'Hospitalet, Spain, 2Idibell, L'Hospitalet, Spain, 3H. Valle Hebron, Barcelona, Spain, 4H. Mutua Terrassa, Terrassa, Spain, 5Instituto Catalan de Oncologia (H. German Trias i Pujol), Badalona, Spain, 6H. St Pau, Barcelona, Spain, 7H. Clinic, Barcelona, Spain, 8Instituto Catalan de Oncologia (H. Trueta), Girona, Spain Background: Standard treatment of newly diagnosed GBM is radiotherapy (RT) with concurrent temozolomide (TMZ), followed by TMZ according to the EORTC/NCIC trial. MGMT promoter methylation status has been correlated with prolonged overall survival (OS) and survival benefit from treatment with TMZ and RT. The aim of our study is to assess the efficacy of this schedule in a cohort of patients (pts) out of a trial, and the prognostic implication of the MGMT methylation. Methods: From March 2002–December 2005 89 pts were reviewed from 8 centers. Kaplan Meier and multivariate analysis (MA) (Cox model) were performed to determine progression (TTP) and OS. DNA was available from paraffin in 71 samples. DNA was modified with bisulfit, and methylation specific PCR (MSP) was performed. MGMT promoter methylation status was assessed in 62 (69%) pts. Results: Median age 57 years (y) (18–80). 61.8% males. Complete resection (CR) in 33.7%, partial resection (PR) 48.3% and biopsy (B) 18%. Median Karfnosky (IK)90% (40–100). 58% needed dexamethasone (DXM) during RT. 92.1% completed RT-TMZ. 80.9% started adjuvant TMZ. 40.4% completed 6 cycles. MGMT methylation was found in: 45.2%. Median follow up 25 months(m). TTP: 7.37m (CI: 5.8–8.89). In the MA age >60y (RR 1.88 CI:1.17–3.04) was significant for recurrence. Median OS: 13.34m (CI 11.77–14.9). Age >60y RR=1.94 (IC: 1.15–3.28) and methylation status of MGMT were significant for survival in the MA. No statistical difference was seen for gender, dexamethasone and IK. Median survival for patients with methylated MGMT: not reached. Median survival for unmethylated: 13.21m (11.79–14.6) (p=0.04). No statistical difference was found in TTP according to methylation of MGMT (p=0.445). Conclusions: Determination of methylation of MGMT is feasible and reproducible in the clinical practice. The % of methylation that we found is similar to previously reported. Age < 60y is a prognostic factor for PFS, age <60, and methylated MGMT are favorable prognostic factors for OS. P185. O6-METHYLGUANINE-DNA METHYLTRANSFERASE IMMUNOEXPRESSION AND SURVIVAL IN PATIENTS WITH HIGH-GRADE ASTROCYTOMA TREATED WITH TEMOZOLOMIDE Y. I. Nakasu1, K. Mitsuya1, S. Horiguchi1, R. Watanabe1, S. Nakasu2; 1Shizuoka Cancer Centre, Nagaizumi, Japan, 2Shiga University of Medical Science, Otsu, Japan Purpose: To assess the efficacy and safety of standard regimens of temozolomide (TMZ) for patients with high-grade astrocytic tumor. Methods: Of 30 patients (18 with glioblastoma, 12 with anaplastic astrocytoma) 20 received TMZ in five-day courses repeated every 28 days, and 10 received radiation therapy plus TMZ for 42 days, switching to the 5/28-day TMZ cyclic regimen thereafter. Tumor tissue from 28 patients was analyzed for O6-methylguanine-DNA methyltransferase (MGMT) expression immunohistochemically. Results: Of the 30 patients followed up for a median of 17 months (6–48 months), 13 (43%) achieved at least partial response (seen by MR images), of whom 12 had gliomas found negative for MGMT expression. Tumor size was unchanged in 10 (33%) patients, six of whom had tumors negative for MGMT expression. Patients with MGMT-negative tumors had significantly longer median overall survival time (OS) than those with MGMT-positive tumors. In patients with glioblastoma, the median OS was 11 months for MGMT-positive tumors, but 29 months for MGMT-negative tumors. In patients with anaplastic astrocytoma, the median OS was 17 months for those with positive MGMT expression, and those with negative MGMT expression have not yet presented their median on a Kaplan-Meier curve. One of the 30 patients developed grade-3 thrombocytopenia, and another developed grade-3 neutropenia; they recovered without sequel. Conclusion: Both TMZ regimens resulted in modest anti-tumor effects with an acceptable safety profile as adjuvant therapy for high-grade gliomas. Immunohistochemical expression of MGMT correlated negatively with response to TMZ. P186*. CORRELATION OF GENOMIC AND EPIGENOMIC CHANGES WITH SURVIVAL IN GLIOBLASTOMA MULTIFORME P. M. J. Clement, A. Wozniak, H. De Schutter, J. Menten, R. Sciot, F. Van Calenbergh, C. Stefan, M. Debiec-Rychter; Leuven Cancer Institute, Leuven, Belgium Introduction: The objective of this retrospective analysis was to identify new genetic and epigenetic prognostic markers in tumor tissue of patients with glioblastoma multiforme (GBM) and to identify novel genes involved in GBM pathogenesis, potentially targeted by therapy with small molecular inhibitors. Material and Methods: DNA was isolated from fresh frozen tumor tissue samples that were obtained from 44 patients with GBM. Array-based Comparative Genomic Hybridization (aCGH) using the Sanger 1Mb Clone Set was performed to identify genetic changes while methylation specific polymerase chain reaction (MSP) was used to detect epigenetic silencing of MGMT, CDKN2A, and CDKN2B. In addition, mutational analysis of CDKN2A was performed. The clinical outcome of the patients was correlated with the most frequently observed genetic and epigenetic changes in the tumor, clinical characteristics and treatment variables. Results: Thirty-six cases (95%) out of 38 analyzed with aCGH showed an aberrant genomic profile with an average of 10.1 changes per case. Losses were more frequent then gains (6.3 vs. 3.8, p<0.001). The most commonly detected genomic change was loss of 10q (27/36; 75%), with two minimal overlapping regions of deletion, 10q21.3–q24.32 and 10q25.1–qter. Total or partial chromosome 9 loss was the second most frequent abnormality (21/36; 58%). Two minimal overlapping regions included 9p24.3–p24.2 and 9p21.3. Homozygous 9p deletion, which covered regions containing CDKN2A and/or CDKN2B was found in 36% of cases. The most frequently detected gain included trisomy of chromosome 7 (29/36; 81%), which was commonly associated with 7p11.2 region amplification (14/36; 39%) that contains EGFR. The highly amplified regions included CHIC/PDGFRA/KIT (5/36 cases), CDK4 (4/36), MDM2 (3/36), MDM4/PIK3C2B (2/36) as well as NRAS, NMYC, PAX3, KRAS and IGF1R (1/36). Using MSP, methylation of MGMT promoter was found in 27.3% of tumors (12/44), while CDNK2A was methylated in 3/44. Methylation of CDNK2B was not present. In addition, in three cases an inactivation mutation of p16 was observed. In total, 15 cases revealed the CDKN2A null phenotype—both alleles of the gene were inactivated either by deletion, promoter methylation or mutation. Age, MGMT promoter methylation and absence of chromosome 7 gain were identified by Kapplan-Meier survival analysis as the best predictors for survival in the studied cohort. Conclusions: (1) Array-CGH has identified novel regions of amplification in GBMs containing genes that may represent additional targets for antitumoral therapy. (2) The methylation status of the MGMT promoter as well as the chromosome 7 copy number gain were confirmed as a predictor for survival. P187. RELEVANCE OF MSP ASSAY FOR THE DETECTION OF MGMT PROMOTER HYPERMETHYLATION IN GLIOBLASTOMAS K. Yachi, T. Ohta, A. Ogino, T. Fukushima, T. Watanabe, A. Yoshino, Y. Katayama; Nihon university, Tokyo, Japan O6-Methylguanine-DNA methyltransferase (MGMT) promoter hypermethylation has recently emerged as a powerful determinant of chemotherapy sensitivity in glioblastomas. To adapt such an important epigenetic biomarker to routine application in the clinical setting, we validated the conventionally used methylation-specific polymerase chain reaction (MSP) assay for its relevance in the determination of MGMT methylation status. MGMT promoter hypermethylation analysis employing MSP was performed on 25 primary glioblastoma samples and 7 cell lines, and compared with the more robust direct promoter sequencing that profiled the methylation status of 27 CpG sites within the MGMT promoter. In addition, the MGMT expression at the protein level was evaluated in the primary tumor samples using immunohistochemistry and in the cell lines using Western blotting analysis. Our MSP analyses yielded reproducible results, which were identical to the bisulfite sequencing data in all except one primary tumor that was negative on MSP. A poor correlation existed between the immunohistochemical staining results and the methylation status of the MGMT promoter in primary glioblastoma samples. Neither MSP-MGMT methylation nor immunohistochemical MGMT expression had prognostic implications in this small and un-uniform group of patients. In all of the cell lines with loss of MGMT expression, signals of methylated DNA were detected by MSP. Our data support the feasibility and reliability of MSP analysis, which could be routinely implemented in the diagnostic setting. P188. RELATIONSHIP AND PROGNOSTIC VALUE OF MGMT (O6-METHYL-DNA-METHYLTRANSFERASE) GENE PROMOTER METHYLATION, AMPLIFICATION OF EGFR (A-EGFR) AND EGFRVIII MUTATION IN A SERIES OF GLIOBLASTOMA (GB) PATIENTS C. Sanz1, J. Ramirez2, N. Ruiz-Xivillé2, C. Carrato1, I. Granada2, F. Millá2, A. Ariza1, S. Villá2, R. Rosell2, C. Balaña2; 1Hospital Universitari Germans Trias i Pujol, Badalona/Barcelona, Spain, 2Institut Català d`Oncologia, Badalona/Barcelona, Spain Background: MGMT (O6-methyl-DNA-methyltransferase) gene promoter methylation predicts benefit from alkylating chemotherapy in GB. Controversial data exist about the clinical value of A-EGFR, a frequent alteration in GB, as well as the presence of the 5' rearrangement of EGFR resulting in the EGFRvIII transcript. The latter has been suggested to define a distinct type of GB. Methods: Seventy samples of treated GB patients (p) were selected for study of: 1/A-EGFR by fluorescence in situ hybridization (FISH) using LSI EGFR/CEP7 probe (Vysis) on a tissue array, 2/MGMT methylation status was analyzed by methylation specific polymerase-chain reaction (MS-PCR) and 3/EGFRvIII mutation by RT-PCR. Clinical factors considered were age (⩾ 50, < 50), surgery (biopsy, resection), KPS (< 70, ⩾ 70%), radiotherapy (no or < 40Gy, 60 Gy), chemotherapy, progression-free survival (PFS), and overall survival (OS). Results: A methylated pattern (MGMT+) was found in 27/70p (38.6%), A-EGFR+ was found in 32/64p (50%), and EGFRvIII mutation (EGFRvIII+) in 18/70p (25.7%). Fifty percent of A-EGFR+ p showed EGFRvIII+. Sixteen (94.1%) EGFRvIII+ p, were A-EGFR+ (P=0.0001). There was no relationship between MGMT and EGFRvIII (P=0.59) or A-EGFR(P=0.50). In 64p the three tests were available. MGMT+ patients showed a longer TTP (P=0.03) and longer OS (P=0.04). EGFRvIII+ p showed longer survival (P=0.03) as well as A-EGFR+ patients (P=0.02). All but 1 p received BCNU or temozolomide based chemotherapy. Multivariate study (age, surgery, PS, radiotherapy, MGMT, EGFRvIII, A-EGFR, and EGFRvIII vs. A-EGFRvIII+) disclosed radiotherapy as the only factor accounting for better OS, and age (<50), radiotherapy, KPS (⩾ 70%), and MGMT+ as independent factors of better PFS. Conclusions: As expected, there is no relationship between MGMT status and A-EGFR/EGFRvIII in GB patients. EGFRvIII+ is commonly associated with A-EGFR+. Only radiotherapy treatment is a persistent and significant factor for better PFS and OS. MGMT+ maintains its independence for PFS probably related to administration of alkylating chemotherapy in almost all p. P189. ANALYSIS OF O6-METILGUANINE-ADN-METILTRANSFERASE (MGMT) METHYLATION, 1P/19Q LOSS AND P53 STATUS IN GLIOMA TUMORS A. Rodríguez de Lope, Y. Ruano, Y. Vicente, Y. Campos-Martín, E. Pérez-Magán, R. Juárez, D. Fuentes, M. Mollejo, J. Hernández-Moneo, B. Meléndez; Hospital Virgen de la Salud, Toledo, Spain The MGMT gene (O6-metilguanine-ADN-metiltransferase) is a DNA repair enzyme that removes alkylating lesions induced by chemotherapeutic agents. Epigenetic silencing of this gene by promoter methylation has been recently proposed as a useful prognostic and/or predictive marker in glioblastoma patients receiving adjuvant therapy (temozolomide) after the surgery. In addition, combined 1p and 19q loss is a relevant marker of chemosensitivity in oligodendroglioma. In order to analyze the MGMT promoter methylation status, we performed a nested methylation-specific PCR assay in a total of 50 samples, including 31 glioblastoma multiforme (GBM), 13 oligodendroglioma (OG), and 6 mixed oligoastrocytoma (OA) tumors. Additionally, p53 gene expression and allelic loss of 1p/19q were studied in OGs and OAs by immunohistochemistry and fluorescent in situ hybridization (FISH), respectively. MGMT promoter methylation was detected in 15 of 31 GBMs (48%), 3 of 6 OAs (50%), and 6 of 13 OGs (46%). Combined loss of 1p/19q was found in 8 of 13 OGs (61%). Survival analyses in these tumors revealed that 1p/19q loss was significantly associated with longer survival (P<0.05). OAs did not show combined loss of 1p/19q, but those cases with MGMT methylation contained p53 mutation. Our results confirm the better clinical outcome of oligodendroglioma patients with combined loss of 1p/19q. Similar frequencies of MGMT inactivation as a result of promoter methylation was found in all glioma subtypes. In OAs MGMT promoter methylation appears to be associated with increased frequency of p53 mutations. P190*. PROMOTER HYPERMETHYLATION, WESTERN BLOTTING ANALYSIS AND IMMUNOHISTOCHEMISTRY OF MGMT IN A SERIES OF 101 GLIOBLASTOMAS M. Mellai1, A. Chiò2, M. Lanotte2, P. Cassoni3, V. Caldera1, L. Annovazzi1, G. Finocchiaro4, D. Schiffer1; 1Neuro-bio-oncology Center Policlinico di Monza Foundation/University of Turin, Vercelli, Italy, 2Department of Neuroscience, University of Turin, Turin, Italy, 3Department of Biomedical Sciences and Human Oncology, University of Turin, Turin, Italy, 4Fondazione IRCCS, Istituto Neurologico C.Besta, Milan, Italy MGMT promoter hypermethylation was investigated in a retrospective study of 101 glioblastoma multiforme cases (GBM). The MGMT status was evaluated by methylation specific PCR (MSP), immunohistochemistry and Western blotting analysis with the relevant antibody in formalin-fixed paraffin-embedded surgical samples. The MGMT gene was found methylated in 29 out of 101 tumors (28.7 %). By immunohistochemistry different categories have been identified on the basis of reaction intensity, percentage of positive cells and homogeneous or heterogeneous distribution. Molecular biology results correlated with immunohistochemistry, but only increasingly with its restriction to homogeneity and high percentage of positive nuclei. A clear-cut correlation of molecular biology with Western blotting was not found, whereas a positive correlation was present between immunohistochemistry and Western blotting (Pearson's correlation coefficient r=0.304, p=0.0335). By Kaplan-Meyer survival analysis, radiotherapy appeared as the major prognostic factor (chi-square test, p=0.001). MGMT methylation status was not prognostic, even after radiotherapy. Temozolomide alone correlated with survival, but much less comparing only radio-treated patients (p=0.005 and p=0.051, respectively). In the latter its correlation with survival only in unmethylated and not in methylated cases (p=0.013 and p=0.82, respectively) was surprising and a matter of speculation. Multivariate Cox regression analysis showed radiotherapy and temozolomide as independent prognostic factors (p=0.0001 and p=0.016, respectively). The major problems encountered were the difficult correlation among molecular biology, immunohistochemistry and Western blotting analysis which required a rather sophisticated score system for quantitative evaluation. The most important bias was the possible clonogenic distribution of MGMT methylation, the whole tumor representativity of the surgical samples and the technical variability of the immunohistochemistry reactions. P191. MGMT AND P15 PROMOTOR METHYLATION— PROGNOSTIC PARAMETERS FOR TEMOZOLOMIDE TREATMENT? S. Wemmert1, R. Ketter1, M. Bettscheider1, S. Alt2, K. Kammers3, J. Rahnenführer3, W. Steudel1, S. Urbschat1; 1Department of Neurosurgery, Saarland University, Homburg, Germany, 2Institute of Immunology, National Public Health Laboratory, Luxembourg, Luxembourg, 3Department of Statistics, Technical University Dortmund, Dortmund, Germany Over the past years aberrant DNA methylation was shown to be a common molecular lesion in human tumors which had also impact on patient prognosis and treatment response. In glioblastoma patients, epigenetic silencing of the promotor gene region of the O6-methylguanine-DNA methyltransferase MGMT is shown to be predictive of response to temozolomide treatment. The aim of our current study was to investigate the methylation status of MGMT and, additionally to our previous findings, p15, p16, 14ARF and correlate these results with the clinical data. DNA was isolated from fresh frozen GBM biopsies (n=27) and modified by sodium bisulfite. Promotor methylation of p15, p16, p14ARF and MGMT was analyzed by MS-PCR. Only patients with a KPS >70, radiation and TMZ-chemotherapy after radical tumor resection were included. We observed promotor hypermethylation of MGMT in 56%, and of p15 in 37% of the tumors, whereas hypermethylation of p16 and p14arf were rare. Our previous study showed that temozolomide increases the median survival time of patients with tumors harboring deletions on 9p within the region for p15 and p16 and deletions on 10q within the region for MGMT. Interestingly, also hypermethylation of p15 emerged as a significant predictor of a shorter overall survival (16.9 vs. 23.8 months, P=0.025; log-rank test), whereas MGMT hypermethylation had no effect on median overall survival (22.5 vs. 22.1 months, P=0.49; log-rank test). In the presence of other clinically relevant factors (age, KPS, sex, MGMT), p15 hypermethylation remains the only significant predictor in the investigated tumors (P=0.021; Cox regression). Although these results need to be confirmed in larger series, our retrospective study suggests that p15 hypermethylation can act as an additional important prognostic factor for survival (and treatment response) in glioblastomas. P192. MGMT PROMOTER METHYLATION STATUS IS A STRONG PREDICTIVE FACTOR FOR RESPONSE TO A RADIATION THERAPY WITH NITROSOUREA (ACNU) BUT NOT TO A COMBINATION THERAPY WITH CARBOPLATINE AND ETOPOSIDE IN GLIOBLASTOMA Y. Narita, H. Momota, Y. Miyakita, S. Shibui; Neurosurgery Division, National Cancer Center Hospital, Tokyo, Japan Objectives: MGMT (O6-methylguanine-DNA methyltransferase) promoter methylation status is associated with a survival benefit in glioblastoma (GBM) patients treated with temozolomide (TMZ). A radiation therapy (RT) plus nitrosourea (nimustine; ACNU) was widely used for the treatment with newly diagnosed GBM patients in Japan before 2005. A combination therapy with carboplatine and etoposide (CE) is used for recurrent GBM patients as a second-line chemotherapy. A retrospective study was performed in order to examine the relationship between MGMT methylation status and the survival benefit treated with these regimens in GBM patients. Methods: Sixty-three newly diagnosed GBM patients were treated with in National Cancer Center Hospital in Japan from 2000 to 2005. RT plus ACNU was used for 47 patients less than 70 years old. Sixteen patients among them were treated with CE regimen after recurrence. Sixteen patients more than 70 years old were treated with only RT without chemotherapy. MGMT methylation status was examined by MGMT-specific PCR (MSP). Results: MGMT was methylated in 42 patients among total 65 patients (64.6%). Median survival time (MST) in 32 patients with methylated MGMT and 15 patients with unmethylated MGMT are 17.9 months and 11.9 months, respectively (p=0.02). MIB-1 staining index of each group are 34% and 30%, respectively. Progression free survival (PFS) of each patient is 5.1 months and 4.4 months, respectively (p=0.08). PFS with CE regimen after recurrence in 10 patients with methylated MGMT and 6 patients with unmethylated MGMT are 3.7 months and 4.9 months, respectively (p=0.8). MST in 11 patients with methylated MGMT and 5 patients with unmethylated MGMT treated with only RT are 6.5 months and 4.0 months, respectively. Conclusions: MGMT promoter methylation status is a strong predictive factor in survival of GBM patients treated with RT plus ACNU but not treated with CE regimen after recurrence. We will also discuss the results treated with temozolomide for glioblastoma patients. P193. MGMT PROMOTER HYPERMETHYLATION AND P53 IMMUNOHISTOCHEMISTRY PREDICT OUTCOME FOLLOWING TEMOZOLOMIDE FOR RECURRENT 1P/19Q NON-DELETED ANAPLASTIC (OLIGO)ASTROCYTOMA J. Sadones1, A. Michotte2, P. In 't Veld2, C. Chaskis2, J. Menten3, E. Joosens4, T. Strauven5, S. Califice6, J. De Greve2, B. Neyns2; 1Vrije Universiteit Brussel, Brussels, Belgium, 2UZ Brussel, Brussels, Belgium, 3UZ Gasthuisberg, Leuven, Belgium, 4AZ Middelheim, Antwerpen, Belgium, 5AZ Sint-Augustinus, Antwerpen, Belgium, 6OMS Belgium, Liège, Belgium Background: Tumor specific molecular-genetic features determine the prognosis and sensitivity to alkylating agents of central nervous system gliomas. The O6-methylguanine-DNA-methyltransferase (MGMT) gene promoter is often hypermethylated in high-grade gliomas (HGG) and is a major determinant of the sensitivity to alkylating agents. The tumor suppressor gene p53 is a frequent target for mutation but its importance as a prognostic or predictive marker has not been established. We investigated the correlation between MGMT methylation status and p53 immunohistochemical staining and the benefit from treatment with temozolomide in patients with recurrent HGG. Patients and Methods: A real-time, quantitative methylation-specific PCR (QMSP) assay for the determination of the MGMT promoter methylation status and immunohistochemical staining for p53 TSG were performed on archival tissue blocks from 38 glioma patients (22 with glioblastoma, 12 with anaplastic astrocytoma [AA], and 4 with anaplastic oligoastrocytoma [AOA], treated with temozolomide at first recurrence. In addition we performed fluorescence in situ hybridization for the characterization of chromosomal loss of 1p, 19q and the 17p13.1 locus (p53) and for gains of the EGFR locus. Results: WHO differentiation grade, MGMT methylation status were significantly correlated with time to progression following temozolomide at first recurrence (Cox logistic regression analysis). Within the subgroups of grade III and IV glioma, significance for these two baseline variables was only observed for patients with anaplastic (oligo)astrocytoma. In this subgroup, as opposed to glioblastoma patients, TP53 IHC positivity more strongly predicted a favourable TTP. None of these 16 anaplastic gliomas had loss of 1p or 19q or amplification of EGFR. MGMT promoter methylation correlated with superior overall survival following temozolomide in patients with AA/AOA but not glioblastoma. Conclusions: The synchronous presence of both MGMT promoter methylation and p53 IHC status appear to be useful molecular markers to predict favourable survival following temozolomide at recurrence only in patients with anaplastic oligoastrocytoma without 1p/19q loss or EGFR amplification. P194. TREATMENT RESULTS AND PROGNOSTIC FACTORS OF NEWLY DIAGNOSED GLIOBLASTOMA T. Ito, K. Sato, M. Oikawa, H. Nakamura; Nakamura Memorial Hospital, Sapporo, Japan Objective: Glioblastomas (GBs) are still most malignant primary brain tumor in adults. The current standard of GBs is surgical resection to the extent feasible, followed by adjuvant radiotherapy and nitrosourea-based chemotherapy in Japan. We retrospectively evaluated the treatment results and prognostic factors of newly diagnosed GBs. Methods: Seventy-nine patients (37 males and 42 females), ages 19–85 years (mean, 60.4) with newly diagnosed GBs, were included in this trial between 7/1993 and 2/2008 at Nakamura Memorial Hospital. All patients were treated with surgery (complete resection in 24 cases, incomplete in 55 cases) followed by radiotherapy and chemotherapy (1-[4-amino-2-methyl-5-pyrimidinyl]methyl-3-[2-chloroethyl]-3-nitrosourea [ACNU] in 51 cases, iemozolomide [TMZ] in 15 cases). We analyzed several prognostic factors for 39 patients who were treated with radiotherapy more than 50 Gy and ACNU chemotherapy followed up more than 1 year; age, gender, preoperative Karnofsky performance score (KPS), extent of resection, intraoperative neuronavigator, proliferative potential (MIB-1 index), and O6-methylguanine-DNA methyltransferase (MGMT) immunohistochemical expression. The Kaplan-Meier survival curves, the log-rank test, and the multivariate Cox proportional hazards model were used to assess the prognostic factors. Results: Median overall survival (OS) was 15 months, and median progression free survival (PFS) was 5 months. Univariate analysis (p=0.036) and multivariate analysis (p=0.034) revealed that the only extent of resection was associated with the good prognosis. Other factors were not significantly associated with OS. There were seven patients with longer survival more than three years. Conclusions: Our results demonstrated that the only extent of resection was associated with longer survival time in patients with GBs who were treated with surgery, radiotherapy, and nitrosourea-based chemotherapy. MGMT immunohistochemistry is a simple and inexpensive method, however, further investigations will be necessary that the level of MGMT expression is an important predictor of the response to the alkylating agents. P195. CHROMOSOME 1P AND 19Q DELETION WITH PREDICTIVE AND PROGNOSTIC VALUE IN LOW-GRADE GLIOMAS A. Pace, C. M. Carapella, R. Merola, I. Sperduti, M. A. Carosi, A. Fabi, A. M. Mirri, A. Vidiri, A. Cianciulli; Regina Elena National Cancer Institute, Rome, Italy Chromosome 1p and 19q loss have been associated with chemosensitivity and with prolonged survival times in patients with low-grade gliomas. To verify the impact of these cytogenetic alterations on the outcome and response to temozolomide chemotherapy, we performed genetic analysis and correlated the preliminary results with patient outcome. Seventy tumors, grade II (WHO) histologically confirmed glioma, 25 astrocytomas (A), 40 oligodendrogliomas (O), and 5 mixed oligo-astrocytomas (OA), were analyzed by FISH (fluorescence in situ hybridization) method for chromosome 1p ad 19q deletion with LSI 1p36/1q25 and LSI 19q13/19p13 dual color probe (Vysis, Inc.). We considered deleted a sample when the ratio was <0.8, and/or monosomy >30% of examined cells was present. There was a correlation between an oligodendroglioma phenotype and chromosome 1p deletion, which was found in 21/40 oligodendrogliomas (52.5%), compared with 5/25 astrocytomas (20%) (p=0.009). A positive trend was found for chromosome 19q deletion, which was present in 6/23 (26.1%) astrocytomas and in 15/39 (38.5%) oligodendrogliomas. The patients, with deletion and oligodendroglioma phenotype, showed a higher objective response rate (90.55 vs 80% for 1p; 93.3% vs 83.3% for 19q), and overall survival (p=0.004 and p=0.01 for 1p and 19 q, respectively). Moreover preliminary data showed that chromosome 1p loss was significantly (p= 0.04) associated with longer survival on univariate analysis. When histological classification, response rate, and chromosome 1p status were entered into a multivariate statistical model, chromosome 1p deletion emerged as significant independent predictor of survival (p= 0.053), (1p intact vs 1p loss, HR: 2,772). Only future larger studies should determine the validity and clinical relevance of this genetic findings, confirming the potential role of molecular prognostic markers in clinical practice. P196. CLINICOPATHOLOGIC ASPECT OF 1P/19Q LOSS TO THE INVASIVENESS OR SENSITIVITY OF CHEMORADIOTHERAPY OF THE ANAPLASTIC OLIGODENDROGLIOMA C. Lee1, M. Kim1, Y. Kang2, M. Joo3, S. Park4; 1Neuroscience institute, Seoul, Republic of Korea, 2Pathology, Seoul Paik Hospital, Seoul, Republic of Korea, 3Pathology, Ilsan Paik Hospital, Ilsan, Republic of Korea, 4Neuropathology, Seoul National University Hospital, Seoul, Republic of Korea Objectives: The author reviewed the pathologic aspect of 1p/19q loss and clinicoradiologic features of the patients with anaplastic oligodendroglioma. We evaluated the relations of the 1p/19q loss and invasiveness of the tumor, or sensitivity of the chemoradiotheraphy of the anaplastic oligodendroglioma. Methods: The authors present twenty cases of pathologically proven anaplastic oligodendroglioma from 1988 to 2007. A retrospective analysis of the clinical presentation, radiological and pathological features, and effectiveness of the treatment was performed and factors relating the status of the 1p/19q loss were investigated. Results: The twenty patients comprised of 11 man and 9 women. The mean age at the diagnosis was 40.6 (16–71). The mean follow-up duration was 58.5 months and four patients died of tumor progression during the follow-up. The most common presenting symptom was seizure. All patients underwent surgery and the tumors were removed as much as possible. Postoperatively, radiation therapy was applied to 16 patients, and PCV (procarbazine, CCNU, vincristine) based chemotherapeutic agent was administrated to 14 patients. Gross total removal was achieved in 14 cases and subtotal was possible in 6, and partial removal was in one case. The patients were well tolerated the toxicity of chemotherapy. During the follow-up, tumor recurrence was observed in 8 patients, and they were treated with additional operations and/or chemotherapy. Seventeen of the 20 patients had a combined loss of 1p and 19q. The status of the 1p/19q loss was not correlated to the tumor invasiveness but related to the sensitivity of the chemoradiotherapy. Conclusions: In this study, the authors confirmed the good response of postoperative chemoradiotherapy in patients with 1p/19q loss anaplastic oligodendroglioma. The gene product loss of 1p/19q does not seem to be related to the tumor invasion. P197. DIAGNOSTIC VALUES OF 1P AND 19Q DELETIONS IN ADULT GLIOMAS: A META-ANALYSIS OF THE LITERATURE AND IMPLICATIONS IN DAILY CLINICAL PRACTICE D. Fontaine1, F. Vandenbos1, C. Lebrun1, V. Paquis1, M. Frenay2; 1Centre Hospitalier Universitaire de Nice, Nice, France, 2Centre anti-cancéreux Antoine Lacassagne, Nice, France Losses of chromosomes 1p and 19q are deemed correlated with the diagnosis of oligodendroglioma. We reviewed the literature to evaluate the usefulness of these correlations to help histological diagnosis in the daily practice. The rates of deletions relative to histology (WHO classifications) were extracted from 33 studies, including 2,666 patients (1,260 oligodendrogliomas, 327 astrocytomas, 603 oligo-astrocytomas and 476 glioblastomas). Mean rates were calculated according to histology and grade. For each grade of malignancy, specificity, sensibility, predictive positive values, and false negative rates have been calculated in order to evaluate the relevance of these deletions to differentiate pure oligodendrogliomas from other tumors (hypotheses 1) and oligodendroglial tumors from pure astrocytomas (hypotheses 2). The 1p deletion, 19q deletion and 1p19q co-deletion mean rates were respectively 65.4%, 69.2% and 63.3% in oligodendrogliomas; 28.7%, 42.2% and 21.6% in oligo-astrocytomas; 13.2%, 23.2%, and 7.5% in astrocytomas; 11.6%, 23.7%, and 2.9% in glioblastomas. The presence of 1p deletion and 1p19q co-deletion were strongly correlated with the histological diagnosis corresponding to oligodendroglioma. High positive predictive values (respectively 77.9% and 84.3% for hypotheses 1; 93.9% and 97.5% for hypotheses 2) suggest that the presence of deletion 1p or co-deletion represents a strong argument in favor of the diagnosis of oligodendroglioma. However, considering the high false negative rates (respectively 34% and 38.6% for hypotheses 1; 67% and 76.2% for hypotheses 2), this diagnosis may not be excluded in absence of such deletions. P198. GENE EXPRESSION BASED CLASSIFICATION OF OLIGODENDROGLIAL TUMORS. TRANSCRIPTOMIC PROFILE ASSOCIATED WITH 1P/19Q ALLELIC LOSSES R. Ferrer-Luna1, H. Martinetto2, M. Mata3, L. Nuñez2, E. Arias2, F. Dasi3, J. Calvar2, J. Piquer4, G. Sevlever2, B. Celda1,5; 1Biophysical and Biomedical NMR Applications Unit. Physical-Chemistry Dpt. University of Valencia, Burjassot, Spain, 2Department of Neuropathology, Fleni. Buenos Aires, Argentina, 3Multigenic Analysis Unit. Faculty of Medicine. University of Valencia, Valencia, Spain, 4Neurosurgery Service. La Ribera Hospital, Alzira, Spain, 5CIBER Bioengineering, Biomaterials and Nanomedicine, ISC-III, Valencia, Spain Introduction: Oligodendroglial tumors (OT) are constituted by pure oligodendrogliomas (OD), and oligoastrocytomas (OA) and their respective anaplastic grades (AOD, AOA). According WHO classification, pure and mixed classes are considered differential tumor entities. Both classes share genetic-molecular alterations but at different frequency. It has been observed that oligodendrogliomas are one of the most chemosensitive solid tumors and that loss of chromosome (LOH) 1p was tightly associated with chemotherapy response. We correlate gene expression with genetic and chromosomal aberrations and investigate whether gene expression profiling could be used to classify OT in an objective manner. Methods: Microarray analysis was used to determine the expression of ∼47,000 transcripts in a set of 16OD, 3AOD, 7OA, and 3AOA. LOH at 1p, 19q, and 10q was assessed by quantitative microsatellite analysis. EGFR and CDK2NA were studied by multiplex RT-PCR. Genes more differentially expressed among molecular groups were selected and evaluated by unsupervised analysis. 17 genes identified in our screen were validated by qRT-PCR using SYBER-Green. Supervised learning approaches were used to build a two class prediction model based on their histology class, pure or mixed. We performed an evaluation of 3 algorithms (DLDA, 1-NN, and PAM) and 8 different prediction model were built in each one (2,5,10,20,35,50,75,100 features). Training error of this prediction models were determined using CV-10, and LOO. The best number of genes that result in the smallest cross-validation error were selected. Results: LOH for 1p, 10q, and 19q was seen in 45%, 45%, and 41% of OT. EGFR amplification, and CDKN2A deletion was found in 14% and 17%, respectively. Expression profile showed that OT with 1p/19q loss, express high levels of genes related with neurogenesis; meanwhile OT with 1p/19q retention over expressed genes related with immune response and inflammation. We identify 72 features frequently used by predictors, the average mixed and pure predictive values were 79.64% and 94.38%. Conclusion: More functionally significant and differentially expressed genes were detected among molecular status than defined histological classes. Gene expression profile was decisively conditioned by 1p/19q allelic deletions. Detected alterations could reveal the divergent response showed by this molecular subgroup in chemotherapy treatment. Molecular predictors could be complementary to pathological diagnosis. P199. GENETIC PROFILE IN 1P-AND 19Q-DELETED OLIGODENDROGLIOMA WITH SHORT RELAPSE-FREE SURVIVAL J. Adachi, N. Uemiya, K. Totake, K. Mishima, T. Suzuki, M. Matsutani, R. Nishikawa; Department of Neuro-oncology, Saitama Medical University International Medical Center, Hidaka-shi, Saitama, Japan Objectives: Oligodendrogliomas (OLs) with combined allelic loss of 1p and 19q have been associated with longer relapse-free and overall survival. However, a subset of 1p- and 19q-deleted OLs recurs early despite post operative chemo-radiothrapy. In this study, we investigated the specific genetic or chromosomal abnormalities found in 1p- and 19q-deleted OLs with short relapse-free interval. Methods: Since 2000, we analyzed six and eight patients with histologically verified OL and anaplastic oligodendroglioma (AO), respectively. Combined loss of both 1p and 19q were confirmed in all cases using fluorescence in situ hybridization (FISH). Post-operatively, all patients received chemotherapy (eight cycles of procarbazine+ACNU+vincristine) and radiation therapy. The follow-up period was the time from diagnosis until death or final contact with the patient. Genetic and chromosomal abnormalities were determined by FISH and/or array-comparative genomic hybridization (Array-CGH). Results: Two of 6 OLs (33%) and two of 8 AOs (25%) recurred within 24 months after initial diagnosis. The remaining 10 cases showed no tumor recurrence during the follow-up period. EGFR amplification was identified in all of recurrent OLs and AOs by FISH and Array-CGH. However, only two AO cases demonstrated EGFR overexpression by immunohistochemical assay. Allelic loss of 10q23 was observed in two recurrent AO cases. In contrast, these alterations were seen in none of patients without tumor recurrence. Conclusions: These results suggest that 1p- and 19q-deleted oligodendroglioma with EGFR amplification or 10q loss, which genetically mimics glioblastoma, tends to recur early. FISH is a simple and useful technique for detecting EGFR amplification in tumor cells. P200. TGF-BETA ANTIBODY TREATMENT OF SUBCUTANEOUS GLIOMAS IN MICE P. Hülper1, W. Kugler1, M. Lakomek1, B. Erdlenbruch2; 1Department of Pediatrics, University of Göttingen, Göttingen, Germany, 2Children's Hospital Minden, Minden, Germany Glioblastoma multiforme is characterized by an intrinsic resistance to radio- and chemotherapy, which is largely responsible for the poor prognosis of patients with high-grade glioma. Thus, new therapeutic strategies are needed. Since TGF-beta is known to be a target molecule for tumor treatment, different kinds of tumors in mice were successfully treated by inhibition or down-regulation of the TGF-beta signaling pathway. For glioblastoma multiforme cell lines reduction of TGF-beta has been shown to either inhibit or promote growth in tumor cell lines and of tumors in mice. Here, human U87MG cells were subcutaneously implanted into nude mice and mouse GL261 cells into Black 6 mice. The resulting tumors were treated with TGF-beta 1–3 inhibiting 1D11 TGF-beta antibodies. Using near-infrared fluorescence labelled antibodies and the eXplore Optix imaging system it was possible to detect the marker antibodies in the tumor tissue in vivo in mice. The anti-TGF-beta-treated tumors in nude mice grew nearly twice as big as tumors treated with an isotype control antibody (13C4). In the xenograft mouse model used here, inhibition of TGF-beta binding to its receptor seems to lead to the established growth stimulatory response and the promotion of tumor growth. The well-known immune escape of gliomas is also triggered by TGF-beta. In the nude mouse model the immune stimulatory effect by inhibiting TGF-beta is almost undetectable because of the low amount of T-cells in nude mice. By contrast, Black 6 mice bearing syngenic subcutaneous GL261 mouse glioma cells are immunocompetent. The effect of the immune response can be compared to the low immune response in glioma growth under TGF-beta treatment. This work was supported by a grant fom Genzyme Corp. P201. TRANSLATION OF IMMUNOTHERAPY AGAINST PEDIATRIC MALIGNANT BRAIN TUMORS A. Darabi, E. Visse, P. Siesjö; Institution for Clinical Sciences, Lund, Sweden Aim: The aim of the described study is to find a basis for clinical immunotherapy of pediatric brain tumors. More specifically, we wanted to investigate whether a tumor specific immune response could be detected in leukocytes from children with brain tumors of different grade of malignancies. Background: Conventional therapy of brain tumors in children can cure many patients but with the cost of severe side effects, most importantly neuro-cognitive deficits. In many cases there is, however, no cure. The advantage of immunotherapy versus conventional therapy is that it specifically targets tumor cells, it can target non-dividing tumor cells, and that it is possible to redesign the therapy after tumor recurrence. Methods and Results: Five pediatric brain tumors of different grade of malignancy have been cultured after surgery. The tumors contained a small proportion of tumor stem cells as determined by the putative stem cell marker CD133, formation of neurospheres under serum free conditions and co-localization of nestin and glial fibrillary acidic protein (GFAP). Leukocytes were isolated from blood and re-stimulated in mixed-lymphocyte-tumor cell-culture (MLTC) against the tumor cells. We could detect CD8/CD107a (CD107a is a marker for granzyme B release and indicates a cytolytic function of the cell) double positive cells, indicating that we could activate tumor specific lymphocytes with a cytolytic function. A panel of Th1 and Th2 cytokines were measured using cytokine-bead-array (CBA). We could detect small amounts of IL-10 and IL-6; both have been reported to be associated with tumor progression. A small piece of the tumor was also minced in order to perform FACS-analysis of the phenotype of tumor infiltrating leukocytes. Of total amount of tumor infiltrating leukocytes, only a fraction was T-lymphocytes. Conclusions: Immunotherapy of pediatric brain tumors may be an alternative treatment modality in the future and it has the advantage to work better in children due to that children have a more active immune system than adults. In order to draw further conclusions about immune activation towards pediatric brain tumors, more patients with different grades of malignancy will be included in the study. P202. COMBINED CHEMOTHERAPY AND IMMUNOTHERAPY AGAINST EXPERIMENTAL MALIGNANT BRAIN TUMORS S. Fritzell, A. Darabi, S. Eberstål, L. Salford, E. Visse, P. Siesjö; Institution for Clinical Sciences, Lund, Sweden Aim: The aim of the described study is to investigate how combined chemotherapy and immunotherapy synergizes in our experimental rat and mouse brain tumor models. Background: The most common of the malignant primary brain tumors, glioblastoma multiforme (GBM), is also one of the most therapy resistant tumors of the human organism. In Sweden, over 400 persons die every year from this disease despite conventional treatments such as surgery or radiotherapy. Based on previously published data from our experimental rat model, we have launched a clinical trial (the BRain Immuno Gene Tumor Therapy-BRIGTT study) with immunotherapy using interferon-gamma (IFNγ) transduced autologous glioma cells in patients with GBM (over the age of 50). The initial eight patients in the clinical trial were immunized after surgery and radiotherapy. Since neo-adjuvant temozolomide (TMZ) treatment in patients with GBM is an accepted clinical treatment the continuing trial will encompass surgery, radiotherapy, and neo-adjuvant chemotherapy using TMZ followed by immunotherapy. Contrary to previous beliefs that the combination of chemo- and immunotherapy might be advantageous due to homeostatic re-constitution of immune cells, reduction of immune cells with suppressive capacity, and release of antigens intra-tumorally. Methods: In our rat and mouse models of glioma, different schedules of chemotherapy using TMZ and immunotherapy using combined cytokines (IFNγ, GM-CSF, IL-7) were launched. The optimal dose and timing of the treatments were determined. Endpoints were primarily survival and secondly assessment of homeostatic lymphocyte re-constitution, reduction of immune cells with suppressive capacity, and intra-tumoral cell-death using flow cytometry and immunohistochemistry. Preliminary Results: Preliminary results show a prolonged survival when combining TMZ with IFNγ-based immunotherapy in our rat glioma model. TMZ by itself did not induce any treatment benefit. Conclusion: Immunotherapy treatment against different forms of cancer is an area that is under expansion, and objective data from clinical trials is accumulating. Nevertheless, new successful therapies have to work in harmony with conventional treatment strategies. It is therefore of uttermost importance to increase the knowledge of how chemotherapy and immunotherapy synergize in the treatment of malignant brain tumors in order to improve the situation for the patients. P203. INHIBITION OF COX-2 AND NO ENHANCES AN IFN-GAMMA BASED IMMUNOTHERAPY OF N32 RAT GLIOMA S. Eberstål, P. Siesjö, W. Badn, M. Esbjörnsson, A. Darabi, E. Vsse; Neurosurgery, Lund, Sweden We have previously developed an immunotherapy against experimental gliomas based on IFN-γ producing tumor cells. Immune suppression triggered both by the growing tumor but also by the induced immune activation down-regulates the immune activation after immunizations. We have previously shown that inhibition of NO by intermittent administration of methyl guanine (MEG) enhanced the cure rate of immunized tumor bearing rats. As MEG has been described to also inhibit COX-2 we wanted to investigate the role of iNOS and COX-2 inhibition after immunizations. Methods: N32 rat glioma cells were stereotactically injected in the right caudate nucleus of syngeneic Fisher rats. Treatment consisting of immunizations with IFN-gamma producing N32 cells (N32IFN-gamma) or medium was combined with delivery of either MEG, the iNOS specific inhibitor L-NIL, or the COX-2 inhibitor parecoxib immunizations were given on days 1, 14, and 28 after establishment of intra cerebral tumors. Results: The survival rate after 120 days was increased in animals treated with immunizations and delivery of L-NIL and parecoxib (7/8) and immunizations and delivery of parecoxib (5/8) compared to immunizations only (4/8) or immunizations and MEG (0/8). Conclusions: The combination of COX-2 and iNOS inhibition enhances the effect of an IFN-gamma based immunotherapy of pre-established N32 rat gliomas. Interestingly continuously administered MEG did not have any effect at all. The results demonstrate that excess production of both prostaglandins and nitric oxide inhibits the therapeutic effect. P204. ENHANCING ANTITUMOR MECHANISMS OF DENDRITIC CELLS VACCINATION BY TEMOZOLOMIDE COMBINATION AGAINST EXPERIMENTAL BRAIN TUMOR Y. Hong1, C. Kim1, D. Chung1, C. Jung2, T. Kim1; 1The Catholic University of Korea, Seoul, Republic of Korea, 2Konyang University, Daejeon, Republic of Korea Many studies have reported that the combination of chemotherapy and immunotherapy may be more effective than the single modality in the treatment of cancers, however, its enhancing antitumor mechanisms are not well known in brain tumors. In this study, we investigated the therapeutic potentials of combination treatment with TMZ and tumor antigen-pulsed DCs and determined the underlying therapeutic mechanisms in an intracranial (i.c.) GL26 glioma model. The combined treatment significantly enhanced the tumor-specific immune responses and prolonged the survival more than the signal therapy in GL26 tumor-bearing animals. Apoptosis induction was detected in the tumor of animals treated with TMZ but not in untreated naïve group. Calreticulin (CRT) surface exposure was also detectable in the TMZ-treated GL26 cells by immunofluorescence staining. In addition, TMZ chemotherapy increased the tumor antigen cross-priming from tumor cells, leading to cross-priming of tumor antigen-specific CD4+ T cells and CD8+ T cells. However, TMZ failed to suppress the number of CD4+ CD25+ regulatory T cells (Treg). Collectively, this study provides the evidence that combined TMZ and DC-based vaccines leads to the enhancement of antitumor immunity through the increased tumor specific immune responses via the cross-priming of an apoptotic tumor cell death mediated by CRT exposure in part. P205. PLASMA PROTEIN BIOMARKER SIGNATURES AS INDICATORS OF THE EFFECTS OF IMMUNO GENE TUMOR THERAPY IN PATIENTS WITH GLIOBLASTOMA MULTIFORME L. G. Salford1, O. Persson1, A. Carlsson2, B. Widegren1, P. Siesjö1, G. Skagerberg1, J. Ingvarsson2, C. Wingren2, C. Borrebaeck2; 1Dept of Neurosurgery, Lund, Sweden, 2Dept of Immunotechnology, Lund, Sweden Malignant brain tumors are still among the most therapy resistant human malignancies. The malignant gliomas which infiltrate the brain are fatal in 99.8%. The mean survival time after diagnosis of a glioblastoma multiforme (GBM) is less than a year in spite of surgery and radiotherapy and chemotherapy administered separately. Based upon our results in animal experiments, we have explored the possibilities of adding immune therapy utilising the patients own tumor cells, transfected with the human IFN-gamma gene by the use of adenoviral vector, followed by 8–14 intradermal immunizations every third week. Patients, all in the age group 50–69 years, who received this treatment after surgery and radiotherapy, had a significantly longer time to progression as well as survival time than a control group. The treatment did not induce observable adverse effects and the treated patients reported improved quality of life during the immunization period. Plasma from all patients were spared before and after initial surgery and before and after each immunization and we have performed differential plasma protein profiling of the non-immunized and the immunized GBM patients as well as of an age-matched group of healthy controls. We have developed a state-of-the art recombinant antibody microarray technology platform for high-throughput proteomics of non-fractionated biotinylated proteomes. The platform is based on human recombinant single-chain Fv (scFv) antibody fragments, microarray adapted by design, on black polymer Maxisorb slides. By the use of this platform we have found, that GBM patients and healthy controls display more similar plasma protein signatures prior to immunization, while distinct signatures were observed after immunization. Furthermore, we have identified tentative plasma protein biomarker signatures distinguishing between short-time (average 345 days) survivors (STS) and long-time survivors (LTS) (average 694 days) among the immunized patients. The level of IFN-γ is higher in LTS than in STS both preoperatively at the 4th and 8th immunization, and IL-5 increases in LTS and decreases in STS during immunization, while IL-12 increases strongly in LTS. In the long term run, such plasma protein signatures may be used for e.g., disease diagnostics, monitoring of the effects of immunization, and prediction of survival—not only for gliomas—based on a simple non-invasive blood test. P206. CYTOGENETIC BASIS OF BENIGN INVASIVE SKULL BASE MENINGIOMAS A. Bekyashev, A. Korshunov, V. Cherekaev, R. Sycheva; Burdenko Neurosurgical Institute, Moscow, Russian Federation Introduction: Meningiomas that arise in the skull base (SBM) often display growth patterns leading to widespread invasion and destruction of the surrounding structures. Consequently, there is still estimated recurrence rate up to 30% with SBM. Conventional cytogenetic studies have failed to reveal aberrations characteristic of invasive meningiomas. Materials and Methods: In total, 15 adult patients who were treated from January 1, 2003, to January 1, 2006, and who had newly diagnosed, histologically benign SBM were included in this study. We investigated 10 invasive and 5 non-invasive SBM using the array-based comparative genomic hybridization with the GenoSensor Array 300. Results: Histological examination of tumor samples revealed 8 meningiotheliomatous and 7 transitional meningiomas, grade I. Mean number of cytogenetic aberrations (CA) detected per tumor was significantly greater for invasive meningiomas—67.4 compared with 40.5 for noninvasive SBM. The frequency of 24 CA (6 losses and 18 gains), affecting > 50% of tumors examined, was found to be relatively similar for both meningioma subgroups. It is of note that all 15 tumors examined showed genomic losses at chromosome 22q and GSCL was found to be most frequently deleted clone (10 samples), followed by TBX1 and BCR loci (6 samples of each). Additionally, 35 CA (16 losses and 19 gains) were found more frequently in invasive tumors (Fisher's exact test, p < 0.05), while frequent losses at 1p, 6q, 9q, and 14q, as well as gains at 7q, 8, 18q, and 20 tended to distribute among invasive meningiomas. We failed to reveal recurrent chromosomal aberrations characteristic of non-invasive SBM alone. Conclusions: The presence of a complex cytogenetic profile and progression-associated chromosomal aberrations in benign SBM is associated with their increased invasive potential. Nevertheless, it is unclear, whether these invasive tumors are already intrinsically aggressive or they can progress in a stepwise cytogenetic fashion. Inasmuch as no reliable adjuvant therapy for recurrent meningiomas is available thus far, revealed genomic aberrations can provide a potential targets for drug discovery and therapeutic intervention in a future. P207. PROGNOSTIC IMPLICATION OF CYTOGENETIC FEATURES IN MENINGIOMAS R. Ketter1, J. Rahnenführer2, W. Henn3, W. Feiden4, W. Steudel1, S. Wemmert1, S. Urbschat1; 1Department of Neurosurgery, Saarland University, Homburg, Germany, 2Department of Statistics, Technical University, Dortmund, Germany, 3Institute of Human Genetics, Saarland University, Homburg, Germany, 4Department of Neuropathology, Saarland University, Homburg, Germany Meningiomas are mostly benign tumors that originate from the coverings of brain and spinal cord. Typically, they reveal a normal karyotype or monosomy for chromosome 22. Rare clinical progression of meningiomas is associated with a non-random pattern of secondary losses of other autosomes. Deletion of the short arm of one chromosome 1 appears to be a decisive step for anaplastic growth in meningiomas. We calculated an oncogenetic tree model that estimates the most likely cytogenetic pathways of 661 meningioma patients in terms of accumulation of somatic chromosome changes in tumor cells. The genetic progression score (GPS) estimates the genetic status of a tumor as progression in the corresponding tumor cells along this model. Large GPS values are highly correlated with early recurrence of meningiomas [p<10-4]. This correlation holds even if patients are stratified by WHO grade. Tumor location also has an impact on genetic progression. Clinical relevance of the GPS is demonstrated with respect to origin, WHO grade, and recurrence of the tumor. As a quantitative measure the GPS allows a more precise assessment of the prognosis of meningiomas than categorical cytogenetic markers based on single chromosomal aberrations. P208. YKL-40 EXPRESSION IN INTRACRANIAL MENINGIOMAS M. Okada, D. Ogawa, Z. Wei, S. Ookubo, K. Miyake, N. Kawai, T. Tamiya; Department of Neurological Surgery, Faculty of Medicine, Kagawa University, Kagawa, Japan Background: A chitinase 3-like-1 protein, YKL-40, is a glycoprotein secreted to the extracellular matrix by various tumor cells. Though the biological role of YKL-40 is yet to be clarified, YKL-40 expression and its relationship to tumor invasion or prognosis are discussed in malignant tumors. In brain tumors, while the expression in glioblastoma has been reported, to our best knowledge, meningioma has not been studied so far. Materials and Methods: Twenty cases with surgically excised meningioma were included in this study; 8 fibrous meningiomas, 4 meningothelial meningiomas, 4 transitional meningiomas, 2 atypical meningiomas, and 2 anaplastic meningiomas were immunohistochemically stained by mouse antihuman YKL-40 monoclonal antibody. We evaluated the presence or absence of YKL-40 expression as well as the localization of expression. Relationship of YKL-40 expression to cell proliferativity indexed by Ki-67 and histological subtypes of meningioma were investigated. Result: YKL-40 expressed dominantly in tumor cytosol and nucleus. YKL-40 expressed in one case out of eight with fibrous meningiomas, and three cases out of four with meningothelial and transitional meningiomas. In malignant meninigomas, one atypical meningioma and all two anaplastic meningiomas demonstrated YKL-40 expression. YKL-40 expression was significantly related to tumor proliferation evaluated by Ki-67 labeling index (p<0.05). Conclusion: YKL-40 was expressed in malignant meningioma and also in benign meningothelial meningioma. YKL-40 expression shed a new light on the further understanding of cell biology of meningioma. YKL-40 may be a potential biomarker alluding to meningioma proliferation as well as other tumors like breast cancer. P209. MICROARRAY-BASED GENE EXPRESSION PROFILING OF BENIGN AND ATYPICAL MENINGIOMAS M. Mata1, C. López-Ginés2, R. Gil-Benso2, O. Cortes3, J. Gonzalez-Darder3, B. Celda4,5, M. Cerdá-Nicolás6,7; 1Fundación de Investigación del Hospital Clínico Universitario, Valencia, Spain, 2Facultadv de Medicina y Odontologia. Universidad de Valencia, Valencia, Spain, 3Hospital Clinico Universitario, Valencia, Spain, 4Departamento de Química Física, Universitat de Valencia, Valencia, Spain, 55Centro de Investigación Biomédica en Red (CIBER-BBN), Valencia, Austria, 6Facultadv de Medicina y Odontologia, Valencia, Spain, 7Centro de Investigación Biomédica en Red (CIBER-RES), Valencia, Spain Meningiomas are one of the most common primary central nervous central tumors accounting for 26% of primary neoplasm. These tumors conform a complex and heterogeneous conjunct. Their wide clinicopatholical variants spectrum is reflected in the 133 histological variants and 3 malignancy grades recognized in the 2000 WHO. Although they are well characterized at the cytological and cytogenetic level, little is known about the molecular pathways critical for meningioma tumor formation and progression. In this study we used Affymetrix's high density microarrays to study 30 meningioma samples. U133 plus 2.0 array, including porbes to analyze more than 45,000 different transcripts, were used to study expression profiles of these tumors. Biotynilated complementary RNA, chip hybridization, and data acquisition were performed following manufacturer's instructions. Statistical analysis was performed using specific algorithms and software developed to analyze microarray data. Five different characteristics were considered in order to find correlations between expression profiles and tumor progression including location of the tumor, histological grade (sincytial, fibroblastic, transitional, secretor or meningotelial), malignity grade, recurrence rate, and karyotype. Biostatistical analysis was done at different levels: Our first approximation was done using the whole data included in the array using non supervised statistical approaches (PCA and hierarchical clustering). Then we increased the complexity of analysis following two different approaches: we selected genes according to biological functions involved in tumor progression, and genes included in chromosomes 1p, 6q, 10, 14q. Several conclusions were extracted from our analysis. We found a poor correlation between location and histology. Benign meningiomas (grade I) conform a more homogeneous group than atypical tumors or anaplasic tumors. Finally we selected a matrix of genes involved in different biological functions (differentiation, cell signaling, cellular cycle, apoptosis, extructural components of cellular matrix, and development) which are useful to distinguish and separate atypical and benign meningiomas inside our samples. This study was supported by grant FIS PI061134 and eTUMOR:FP6-2002-LIFESCIHEALTH 503094e. P210. PEDIATRIC NON-EPENDYMAL GLIOMAS HAVE GENETIC ABERRATIONS DIFFERENT FROM ADULT TUMORS T. Miwa1, Y. Hirose2, H. Sasaki1, K. Yoshida1, T. Kawase1; 1Department of Neurosurgery, Keio University, Tokyo, Japan, 2Department of Neurosurgery, Fujita Health University, Toyoake, Japan Recent progress in genetics for brain tumors revealed that genetic analysis provides information relevant to clinical course of glioma patients. However, knowledge in genetic aberrations in glioma has been obtained mainly from adult tumors, and little is known for pediatric tumors. To characterize pediatric non-ependymal gliomas by their genetic features, we investigated DNA copy number aberrations (CNAs) in pediatric non-ependymal gliomas using comparative genomic hybridization (metaphase CGH). To exclude intermixed normal brain tissue, especially in case of low grade tumors, we microdissected the small pieces of paraffin-embedded tissue that were histologically confirmed as neoplastic region, and DNA extracted from those microdissected tissues were subjected to analysis. We found gain on chromosomal arm 1q, 7q, 9q, and 17q frequently in our study cases. These CNAs were recognized in both supra- and infra-tentorial tumors. Especially, gain on 1q was frequent in tumors of histologically high grade and clinically aggressive, irrespective to tumor location and tumor cell type, and was associated with a higher number of CNAs. Loss of 1p and 19q, the most frequent aberration in adult oligodendrogliomas, respectively, were not recognized. Our analysis detected no CNAs in cerebellar pilocytic astrocytomas. Compared with CGH data which we have already obtained from more than 180 adult astrocytic and oligodendroglial tumors, pediatric non-ependymal gliomas had CNAs distinct from adult cases. This difference of genetic features supports the idea that pediatric tumors develop via unique pathways. Further investigation is warranted to identify genetic markers which may help development of treatment strategy for pediatric gliomas. P211. COMPARATIVE GENETIC AND METABOLIC STUDY IN A METASTASIZING ANAPLASTIC EPENDYMOMA IN AN ADULT C. López-Ginés1, C. Faus2, R. Gil-Benso1, D. Monleon3, M. Mata3, J. Morales3, J. Leon2, J. Gonzalez-Darder2, B. Celda4,5, M. Cerdá-Nicolás6,7; 1Facultad de Medicina y Odontologia, Valencia, Spain, 2Hospital Clinico Universitario, Valencia, Spain, 3Fundación de Investigación del Hospital Clínico Universitario, Valencia, Spain, 4Departamento de Química Física, Universitat de Valencia., Valencia, Spain, 5Centro de Investigación Biomédica en Red (CIBER-BBN) Valencia, Spain, 6Facultad de Medicina y Odontologia, Universidad de Valencia, Valencia, Spain, 7Centro de Investigación Biomédica en Red (CIBER-RES), Valencia, Spain Ependymoma is a tumor of neuroepithelial tissue that occurs in both brain and spinal cord, most frequently in children and young adults. Recurrence of tumor in the same site as the original one is a known complication especially in association with subtotal or incomplete resection. However, dissemination and metastasis has only rarely been described. Microscopic examination of original tumor showed a highly cellular picture of anaplastic ependymoma. Neoplastic cells presented cellular and nuclear pleomorphism, and perivascular rosettes. Metastatic tumor in cerebellum showed an increasing of cellular anaplasia with a diffuse organization. The original neoplasm and the metastasis showed frequent mitotic activity and a high proliferative index of Ki67-LI; this last increased in anaplastic areas of the metastatic tumor. Both tumors expressed GFAP, S100, and p53. Chromosomal analysis using G-banding and spectral karyotyping (SKY) showed the karyotype was the same as well in the original tumor as the metastasis with anomalies in chromosomes 2, 3, 5, 8, 16, and X. Interphase fluorescence in situ hybridization (FISH) analysis in culture cells and paraffin in both tumors revealed no deletion for TP53, no amplification of EGFR, and homozygotic deletion in INK4A in both tumors. Gene expression profiles were obtained using Affymetrix microarrays. A total of 1,362 annotated genes were identified as changed between metastasis and baseline sample, original tumor. These genes are involved in cell cycle control, cell differentiation, response to DNA damage, and extructural genes. The TP53, IGF-2, PRDX2, many collagen, cyclins, MAPkinases and heat shock proteins to be highly expressed in metastasis. The comparison between the high resolution magic angle spinning (HR-MAS) spectra of original and metastatic ependymoma and CNS normal tissue show a strong decrease of N-acetyl-aspartate, which reflects cellular destruction, and of creatine, which indicates a decrease of the energetic metabolism. Metabolic profiles for both samples are almost identical with some variations in the levels of phospholipids and related metabolites. To our knowledge, the present study is the first report of a genetic study of an original tumor and its metastasis in an anaplastic ependymoma. The genetics results in both tumors are similar, but there is a different expression of some genes and metabolic profiles related to increase of malignancy. This study was supported by grant FIS PI061134. P212. COMPARATIVE EPIGENETIC ANALYSIS OF THE MALIGNANT PROGRESSION OF PLEOMORPHIC XANTHOASTROCYTOMA R. Martinez1, O. Basten2, S. Ropero3, E. Hofmann4, A. Giese1, R. Behr5, M. Esteller3; 1Department of Neurosurgery, University of Goettingen, Germany, 2Institute of Pathology, Klinikum Fulda, Germany, 3Spanish National Cancer Centre, CNIO, Madrid, Spain, 4Department of Neuroradiology, Klinikum Fulda, Germany, 5Department of Neurosurgery, Klinikum Fulda, Germany Objective: Pleomorphic xanthoastrocytoma (PXA) is a rare WHO grade II tumor accounting for less than 1% of all astrocytomas. The biological behavior of PXA is benign with a 10-year survival rate of 70%. Malignant transformation of PXA is extremely unusual. We report the exceptional case of a patient harboring a WHO grade II right parietal PXA. 12 months after total resection a local relapse occurred. Histologically the recurrent tumor showed anaplastic features. Methods: Both tumor specimens were assessed by histological, immunohistochemical and molecular analyses. After DNA extraction methylation specific polymerase chain reaction (MSP) was applied for pro-apoptotic genes (CASP8, CASP3, CASP9, DcR1, DR4, DR5, TMS1), tumor suppressor genes (RASSF1A, BLU), cell adhesion regulating genes (CDH1, CDH13), cell cycle regulator genes (CHFR, p14ARF, p16INK) and DNA repair genes (MGMT, hMLH1). Bisulfite sequencing was performed to confirm MSP data. Results: Both tumors were similar regarding immunopositivity against GFAP, S100, vimentin, and EMA. The proliferation activity (assessed by MIB1) was higher in the malignant specimen (20% vs. 10%). p53 immunopositivity was more frequently observed in the anaplastic sample (20% vs. 10%). RASFF1A, TMS1, and MGMT were hypermethylated in both tumors whereas BLU and DR4 showed a new methylation in the anaplastic tumor not previously observed in the benign specimen. Conclusions: The anaplastic features of the 2nd PXA were underscored by higher tumor proliferation activity and p53 accumulation. Anaplastic transformation of PXA was accompanied by epigenetic inactivation of the tumor suppressor gene BLU and the pro-apoptotic gene DR4. Our data further suggest that methylation mediated inactivation of RASFF1A, TMS1, and MGMT may be early events in the pathogenesis of PXA. P213. CXCL12 AND CXCR7 EXPRESSION IN BRAIN METASTASES A. Salmaggi, E. Maderna, C. Calatozzolo, P. Gaviani, A. Boiardi, F. Di Meco, I. Milanesi, A. Silvani, B. Pollo; Fondazione IRCCS Istituto Neurologico C. Besta, Milano, Italy Brain metastases occur in about 25% of patients who die of cancer. The most common sources of brain metastases in adults are lung, breast, kidney, colorectal cancer, and melanoma. The chemokine/receptor system CXCL12/CXCR4 plays a key role in multiple biological functions, among these, the homing of neoplastic cells from the primary site to the target and the progression of the metastasis. Recently, an alternative CXCL12 receptor, CXCR7, has been discovered. Recent data underscore the relevance of CXCL12/CXCR4 pathway in the metastatization process in a large number of tumors, although the relationships with clinical outcome (survival time) has not been investigated in detail. The aim of our study was to investigate by immunohistochemistry the expression of CXCL12 and their receptors CXCR4 and CXCR7 in brain metastases from different non-CNS primary tumors in 56 patients operated on over 2 years in our institution, and to evaluate putative correlations of immunohistochemistry data and of other well-known prognostic factors with clinical outcome. At univariate analysis, we found statistically significant correlations with overall survival for RPA class (p=0.003 log-rank), single versus multiple metastasis (p=0.01 log-rank), early versus delayed or no post-surgery WBRT/SRS (p=0.02 log-rank), further treatment at recurrence (p=0.0002 log-rank). Among the investigated immunohistochemistry parameters, only CXCL12 expression in endothelial cells showed a statistically significant correlation with worse outcome (p=0.04 log-rank). We found immunohistochemical expression of CXCR7 in tumor and endothelial cells, suggesting a potential role of this receptor in facilitating the passage across the blood-brain barrier of CXCR7 positive metastatic cells. Thus, we have provided a first evidence of CXCL12/CXCR7 expression in brain metastases. P214*. TOWARD BRAIN TUMOR CLASSIFICATION BY MOLECULAR PROFILING: IMAGING, METABOLOMIC, AND GENOMIC TOOLS B. Celda1, D. Monleon2, J. Piquer3, J. Llacer3, A. Revert4, E. Molla4, M. Martinez-Bisbal1; 1CIBER-BBN-Universitat de Valencia, Burjassot (Valencia), Spain, 2Fundacíon Investigacion Hospital Clinico Universitario Valencia, Valencia, Spain, 3Neurosurgery Service Hospital La Ribera, Alzira (Valencia), Spain, 4Radiology Service Hospital La Ribera, Alzira (Valencia), Spain Introduction: There is an increasing interest for deeper biochemical knowledge of brain tumors for improving their diagnosis and for monitoring the treatment response. Proton magnetic resonance spectroscopy (1H MRS) is the only non-invasive technique able to investigate brain tumor molecular profiles and to provide molecular images. In addition, there are new molecular techniques that can provide detailed biochemical information in tumor biopsies: high resolution MR at magic angle (HR-MAS) and DNA microarrays. The aim of this communication is to verify the complementarity among in vivo 1H MRS and ex vivo metabolomics (HR MAS) and transcriptomics (DNA microarrays) data for improving the diagnosis and prognosis of brain tumor using multicenter protocols of a European project (eTUMOUR). Material and Methods: In vivo 1H MRS and ex vivo HR MAS and DNA microarrays were applied in 50 patients with histological diagnosis of: GBM, astrocytoma, meningioma, oligodendroglioma, oligoastrocytoma and metastasis. The range of tumor biopsy used was 16–35 mg. MRI studies were acquired in a clinical 1.5T instrument (Philips). 1H MRS protocols enclose SV (TE 31 and 136 ms) localized in the lesion, with TR=2,000 ms. The SV was adjusted to the largest cellularity region of the lesion by using spectroscopy imaging (CSI) (TE 272 ms). HR MAS studies were done at 0C and 4 KHz spinning in 11 and 14T instruments (Bruker). Standard methods of biopsies RNA extraction were applied in the 50 patients. The quality was verified through spectrometric analysis using Agilent bio-analyzer. The expression alterations were analyzed by using pangenomic Genechip Human-Genome U133Plus2.0. Results: In vivo (1H MRS) and ex vivo (HR MAS) metabolic profiles have allowed differentiating among different brain tumors through a particular set of metabolites (lipids, choline, mio-Inositol, alanine, among others). Likewise, the alterations in transcription processes (EGFR, PTK, etc.) has also allowed a molecular differentiation among brain tumors. Conclusions: The combined use of 1H MRS, HR MAS, and DNA microarrays multicenter protocols has provided a set of biomarkers for a molecular classification of brain tumors, allowing the identification of tumor subtypes (as in GBM and meningiomas) and correlation with survival. This set of biomarkers can be used for improving the diagnosis and prognosis and for helping in a better selection and control of the therapy of brain tumors. P215. ALLELOTYPING SIGNATURES TO DIFFERENTIATE PEDIATRIC AND ADULT GLIOMAS ON DIAGNOSTIC SAMPLES N. Entz-Werle1, E. Guerin2, M. Legrain1, A. Neuville1, D. Maitrot1, P. Lutz1, P. Kehrli1, M. Gaub2; 1CHRU Strasbourg, Strasbourg, France, 2Inserm U682, Strasbourg, France Background: Brain tumors are a heterogeneous group of cancers in adult and pediatric populations. To differentiate them at molecular level and to understand their molecular characteristics and oncogenesis, a molecular study was designed to screen by allelotyping the pediatric and adult populations referred in our centre for treatment from January 2004 to July 2007. Methods: 92 patients were included after informed consent: 24 oligodendrogliomas (7 grade A, 3 grade A/B, and 14 grade B), 60 gliomas (15 juvenile pilocytic astrocytomas (JPAs), 12 low and intermediate-grade gliomas, 30 glioblastomas (GBMs) and 3 pediatric high-grade gliomas (HGG), and 8 medulloblastomas. Paired normal and tumor DNAs were analyzed by allelotyping with 44 microsatelllites located in DNA regions containing cell cycle and differentiation genes and new potential therapeutic targets, as P53, APC, TOP2A, TWIST, etc. The association with histological subroups was examined using the chi-square test and combined with a PLS analysis. Results: No microsatellite instability, only allelic imbalance (AI) were detected which is the witness of both locus deletion and amplification without any precision of the real status of the locus. The high frequency of AI was mainly correlated to high grade histologies. Each histological subgroup could be at least characterized by a molecular signature and a discriminative analysis was shown significantly with the PLS analysis. Then, JPAs were only defined by the presence of 22q13 and 4p16 abnormalities, whereas GBMs were defined by the 7p21, 7q21, 7q31, 9q34, 10p13, 13q33, and 18q22 rearrangements. The oligodendrogliomas were mainly characterized by 1p and 19q AI associated with a specific panel of abnormalities for each grade. MBs were underlined by the accumulation of AI in 2q13, 8p23, and 17q11 and pediatric HGGs in 7p, 7q, 9q34, and 15q24. In high grade BTs, no abnormalities in 5q and in 20q11 were found. Conclusions: A wider cohort is mandatory to define more robust molecular conclusions, but these results are to be considered as the beginning of a more accurate basis for BT molecular characterization and differentiation. P216. TOWARD A EUROPEAN BRAIN TUMOR DATA BANK L. Bauchet1, V. Rigau2, H. Mathieu-Daudé3, D. Figarella Branger4, P. Fabbro5, L. Taillandier6; 1Neurosurgery, CHU Montpellier, Montpellier, France, 2Pathology, CHU Montpellier, Montpellier, France, 3Epidemiology Centre Anti Cancereux Montpellier, Montpellier, France, 4Neuropathology CHU Marseille, Marseille, France, 5Biostatistics CHU Nîmes, Nimes, France, 6Neuro-Oncology CHU Nancy, Nancy, France In order to develop cooperation between different countries in Europe, the goal of this presentation is to share an experience about collecting brain tumor data and to suggest the possibility to create a European brain tumor data bank. The French societies involved in neuro-oncology (Association des Neuro-oncologues d'Expression Française, Société Française de Neurochirurgie, Société Française de Neuropathologie) have recently created the French Brain Tumor Data Base (FBTDB). For each patients with histologically confirmed primary central nervous system tumor (PCNST), the neurosurgeon and the neuropathologist complete an easy data file containing socio-demographic, clinical, radiologic, and anatomopathologic information (including knowledge of cryopreservation of specimen). In 4 years, 16,753 cases of newly diagnosed PCNST have been recorded. Histological diagnoses included glioma (49.2%), other neuroepithelial tumors (4.8%), meningioma (30.3%), neurinoma (8.3%), lymphoma (2.9%), and others (4.5%). Cryopreservation was reported for 4021 PCNST specimens. Clinical and radiological aspects were also recorded. Tumor resections were performed in 75%, while biopsies accounted for 25. The median age (MA), sex, and the number of cryopreserved tumors for each histology will be detailed to the presentation (by example, on 3,819 glioblastomas [MA: 63 years, male: 58%], 1,023 were cryopreserved, on 23 atypical teratoid/rhabdoid tumors [MA: 5 years, male: 59%], 12 were cryopreserved). The EANO meeting is a good opportunity to discuss the possibility to create a European brain tumor data bank. P217. MET TYROSINE KINASE RECEPTOR EXPRESSION IN PITUITARY ADENOMAS S. Kim, B. Lee, H. Kim, J. Lee; Ajou University School of Medicine, Suwon, Republic of Korea Met tyrosine kinase receptor is known as the receptor of hepatocyte growth factor (HGF) and met-HGF signaling has been shown to affect a wide range of biological activities, including angiogenesis, cellular motility, growth, and morphogenic differentiation. However, little is known regarding its significance in benign brain tumors. The goal of this study is to verify met-expression and its implication in pituitary adenomas. Total RNA was extracted from the 29 surgical specimens obtained during pituitary adenoma surgery and the samples were subjected to RT-PCR using human wtMet and Δ13Met primers. Following PCR amplification, the products were analyzed by electrophoresis and the relationship between their expression and clinico-radiological factors was evaluated. There were 11 functioning (hormone-secreting) adenomas and 18 nonfunctioning adenomas. Among 29 adenomas, wtMet was expressed in 19 tumors and the incidence of its expression was significantly higher in functioning adenomas (90.9%) compared to nonfunctioning adenomas (50%). And patients' age was significantly younger in wtMet expressed group (mean: 42.8 years) compared to non-expressed group (mean: 55.1 years). Other clinico-radiological factors, such as invasiveness documented as sellar floor destruction or cavernous sinus invasion on MR imaging, were not related to wtMet expression. Δ13Met was expressed in only 4 adenomas (1 functioning and 3 nonfunctioning). Our results showed a positive relationship between wtMet expression and functioning status of pituitary adenomas. We suggest that wtMet expression might be one of the markers of functioning pituitary adenomas and its clinical implication should be studied further. P218. THE EXPRESSION OF SDF-1 IN PITUITARY ADENOMA R. Nomura, D. Yoshida, A. Teramoto; Nippon Medical School, Tokyo, Japan Objective: Recent study has disclosed that a chemokine, stromal cell-derived factor-1 (SDF-1) has a homing effect, recruiting endothelial progenitor cells (EPC) from the bone marrow to injured or ischemic tissue. In this study, we investigated the relationship between the expression of SDF-1 and CD34 in pituitary adenomas aiming to discuss its origin of angiogenesis. Methods: The expression of SDF-1 by mouse pituitary adenoma cell lines (AtT20) was quantitatively elucidated by ELISA in hypoxic condition. Double immunofluorescence study was performed with anti-SDF-1 and anti-CD34 antibodies in 59 pituitary adenomas of paraffin-embedded tissue samples. The relationship between expression of SDF-1- and CD34-positive vessels was statistically analyzed. Results: ELISA study indicated that the secretion of SDF-1 in AtT-20 was enhanced by hypoxic stimulation in a concentration-dependent manner. Immunohistochemistry showed that though SDF-1 expressed throughout subtypes of pituitary adenomas, there were no significant differences among each subtype. CD34-positive vessels was significantly increased along with elevated SDF-1 expression. The expression of SDF-1 was significantly seen in macroadenomas. Conclusion: The current study highly implicated that SDF-1 is a crutial factor of angiogenesis by the homing effect to mobilize CD34-positive endothelial progenitor cell from the bone marrow to pituitary adenomas. P219. EXPRESSION OF ABC TRANSPORTER PROTEINS AND VEGFR2 IN THE HUMAN MALIGNANT GLIOMAS K. Miyake, D. Ogawa, M. Okada, S. Ookubo, T. Tamiya; neurological surgery, Kagawa kita-gun miki-cho, Japan Background: Glioblastoma patients have a median survival of approximately 12 months following surgical resection and radiotherapy, and temozolomide increased the median survival from 12 to 15 months, but as with other regimens, it does not lead to cure, because the blood brain barrier (BBB) is one of the problems in chemotherapy for the central nervous system (CNS) cancers. The BBB forms a very effective barrier to the free diffusion of many polar solutes into the brain. Many metabolites that are polar have their brain entry facilitated by specific inwardly directed transport mechanisms. These molecules are substrated for the ABC (ATP-binding cassette) transporter proteins which are present in BBB, and the activity of these transporters very efficiently removes the drug from CNS, thus limiting the brain uptake. The malignant gliomas are among the highest vascularized tumors. In the process of vasculogenesis, de novo formation of blood vessels from bone marrow–derived endothelial progenitor cells (EPCs) takes place. The two surface markers CD133 and VEGFR2 characterize the primitive EPCs. So, we hypothesized that patients with the malignant gliomas have increased levels of EPCs, and the increased EPCs and amplified ABC transporter proteins reportedly play roles in the cancer chemotherapy problems. Methods: In the present study, we investigated the ABC transporter proteins (MDR1, MRP1, MRP2, and ABCG2), CD133, and VEGFR2 in human malignant gliomas specimens (24 glioblastoma multiformes [GBM], 13 anaplastic astrocytomas [AA]) using RT-PCR assay and immunohistochemical staining. Results: We detected MDR1 (23 GBM, 13 AA) and ABCG2 (21 GBM, 11 AA) in the microvessel endothelium. Moreover, we noticed different expression levels of MRP genes in each patient individually. We observed overexpression of CD133 and VEGFR2 in the recurrent glioblastoma. Glioblastomas with MDR1, ABCG2, CD133, and VEGFR2 amplification have a median progression free survival (PFS) of approximately 6 months, but glioblastomas with no amplification of CD 133 and VEGFR2 have a median PFS of 12.3 months. Conclusions: CD 133 and VEGFR2 amplification correlated with the recurrence of glioblastoma. Glioblastomas with MDR1, ABCG2, CD133, and VEGFR2 amplification tend to have a tendency a shorter median PFS. The increased EPCs and amplified ABC transporter proteins probably resist the cancer chemotherapy with consequent poor outcomes in glioblastoma. P220. REFERRAL FOR SUSPECTED BRAIN OR CNS TUMOR IN THE UNITED KINGDOM: AN AUDIT OF THE EFFICACY OF NATIONAL GUIDELINES D. Holliman, P. Kane; James Cook University Hospital, Middlesbrough, United Kingdom Background: In the United Kingdom (UK), primary care physicians refer patients with suspected diagnosis of brain or CNS tumor according to guidelines published by The National Institute for Clinical Excellence (NICE) in June 2005. Patients referred under these guidelines must not wait longer than two weeks to be seen by a specialist. The efficacy of these guidelines in improving the detection of brain tumors is unclear. Objective: To assess the referral patterns and efficacy of NICE guidelines in making a new diagnosis of brain tumor. Design: Retrospective case note review of patients referred under the NICE guidelines between April 2006 and March 2007. Results: Records of 73 patients were reviewed, (36 female, 37 male). Median age was 48 years (range 19–82 years). Only 3 (4%) patients referred using these guidelines resulted in a new diagnosis of CNS tumor. Six (8%) patients were referred with a pre-existing diagnosis of CNS tumor, usually as the result of primary care physician scanning. The most common diagnosis was headache/migraine in 23 (31.5%) patients. Only 44 (60%) patients appeared to have symptoms or signs for which the guidelines recommend referral. Conclusions: Analysis reveals that patients referred using NICE guidelines have a low yield of new tumor diagnosis and thus the NICE guidelines appear somewhat insensitive. This parallels findings in other areas of oncology using similar referral systems in the UK. We are unaware of equivalent guidelines being used in Europe. Guidance for UK primary care physicians regarding referral patterns or revision of the guidelines may be needed. P221. POPULATION BASED SURVIVAL OF CENTRAL NERVOUS SYSTEM (CNS) MALIGNANCIES IN THE GIRONA PROVINCE (SPAIN): RESULTS OF AN 11 YEAR SURVEY (1994–2004) R. Marcos-Gragera1,2, R. Fuentes Raspall1,2, L. Vilardell1, G. Barraza3, C. Joly3, M. Garcia-Gil2; 1Institut Catala d`Oncologia, Girona, Spain, 2Institut d`Investigació Biomedica de Girona (IDIBGi), Girona, Spain, 3Hospital Josep Trueta, Girona, Spain Background: Epidemiological data regarding survival of CNS malignancies are infrequently reported. We present an updated assessment of survival rates obtained from the Girona population-based cancer registry. Patients and Methods: The analysis included all cases of primary CNS malignancies registered during the period 1994–2004. Pathological diagnoses were reviewed and grouped according to the last WHO classification of Tumors of the CNS (2007). Meningeal, soft tissue tumors and primary CNS lymphomas were excluded from the survival analysis. Cases notified only by death certificate (27 cases [5.5%]) were also excluded. Dates of diagnosis and death and/or the end of the study (December 31, 2005) were used to estimate the survival rates by the Kaplan-Meier method. Results: A total of 493 patients were registered during the 11 year survey. Distribution by histology was: astrocytic tumors = 243 (49.3%); oligodendroglial and oligoastrocytic tumors = 17 (3.4%); ependimal tumors = 13 (2.6%); embryonal tumors = 18 (3.7%); and CNS primary malignancies without histological confirmation = 202 (41.0%). The mean ages for embryonal tumors and CNS primaries without histological confirmation were respectively: 18.2 yrs. and 66.3 yrs. Five-year overall survival rates were: astrocytic tumors=14.6%; oligodendroglial and oligoastrocitic tumors=35.7%; ependimal tumors=41.0%, embryonal tumors=32.4%, and CNS malignancies without histological confirmation=7.5%. Discussion: In agreement with earlier studies, Kaplan-Meier curves showed that ependimal and oligodendroglial tumors were the histological groups having a better survival rates. The worst survival ocurred in the group of patients with CNS malignancies without histological confirmation. These findings suggest that a more conservative management appears to occur during the diagnosis and treatment of elderly or poor-prognosis sub-groups of patients in our area. P222. COMPARISON OF CNS NEURO-ONCOLOGY CENTER AUDIT 2005 AND 2007—UK AND IRELAND H. Lee1, A. K. Gilbert2, R. MacArthur3; 1Sheffield Teaching Hospitals NHS Trust, Sheffield, United Kingdom, 2ANON, London, United Kingdom, 3Kings, Guys and St Thomas's Hospitals, London, United Kingdom Aim of Study: To compare the results of in-depth information gathered in 2005 to the same data collected in 2007, post NICE Guidance (June 2006) about all aspects of the neuro-oncology services offered throughout the UK and Ireland. Background: Over the last few years there has been a dramatic rise in the service needs for the neuro-oncology patient and their family. The role of the clinical nurse specialist (CNS) has become much more comprehensive since NICE guidance was introduced. The incidence of brain and CNS primary tumors is 15–16 per 100k population and is increasing. Method: 49 CNS's that work in centers in the UK and Ireland were sent the same questionnaire as they were sent in 2005 in 2007 post NICE guidance. 33 surveys were collected from neuro-oncology centers in the UK and Ireland. In 2005 (pre NICE guidance) 32 surveys were included. Results: Newly diagnosed patients seen by CNSs included: high or low grade tumors, metastatic and pituitary. There are more low grade tumors being seen (2% in 2005, 22.5% in 2007) an increase of 20.5%. High grade, metastatic and pituitary have not changed dramatically. Overtime has increased; 63% worked a minimum 6–10 hours overtime every week, an increase of 28% since 2005 (35%); 34% of CNSs ran nurse led clinics in 2007 similar to the 33% in 2005. There are less MDT co-ordinators working full time in neuro-oncology in 2007 a decrease of 2% since 2005. Meetings have now moved from weekly (82.14% in 2005) to monthly (71.4% in 2007) neuro-oncology patients are still mainly given their histology results in the neuro-surgical unit and by the neuro-surgeon. The CNS is still very much present at this time for the patient, nearly 82% in 2007, and 85% in 2005. Just as in 2005, nearly 100% of CNSs had teaching responsibilities. 93% of units had an MDT in 2007, a decrease of 4% since 2005 (97%) And 33.3% of those did not have a co-ordinator, leaving more of this responsibility to the CNS in 2007. Out of the 60.6% (53% in 2005) of units that ran regular patient support groups, 75% (84% in 2005) of these sessions were run voluntary out of working hours. The number of units with a dedicated research nurse has reduced dramatically from 72% in 2005 to 57% in 2007 increasing the workload of the CNS. Conclusion: There is a need for more resources and personnel to address the growing workload of the neuro-oncology CNS. This workload has increased dramatically since NICE guidance was introduced in June 2006. There are gaps in the provision of service for the neuro-oncology patient and their family in the UK and Ireland today due to lack of resources and manpower. P223*. WHO GRADE II-III GLIOMA DIAGNOSED BEFORE 2000 RECLASSIFIED IN LIGHT OF THE NEW CLASSIFICATION ACCORDING TO IMMUNO-HISTOCHEMISTRY AND IMAGING: A RETROSPECTIVE STUDY OF 129 PATIENTS M. Fabbro1, A. Maran2, V. Rigau2, L. Bauchet2, H. Duffau2, P. Peray3, V. Costes2; 1CRLC, Montpellier, France, 2CHU, Montpellier, France, 3CHU, Nimes, France Rationale: Most studies have emphasized the discrepancies in glial tumors' classification. The aim of this study was to describe how patients with WHO grade II-III glioma diagnosed before 2000 are classified according new WHO classification and imaging. Methods: Patients with grade II-III glioma were extracted from the pathological database of neuro-surgery hospital, Montpellier, since 1990 to 2000. In a blind procedure, slides were prepared from paraffin embedded blocks. Immuno-chemistry staining was performed with GFAP, p53, neuN, synaptophysine, and Ki 67. A new morphological and IHC interpretation was performed. When available, MRI was interpreted according gadolinium enhancement (Gad Enh) or not, allowing Sainte Anne classification. Overall survival (OS) was calculated from diagnostic date and date of dead. Results: 129 pts fullfilling the criteria were identified in the database; MRI and sufficient block material for second interpretation was available for 81 pts; 43% were female and 57% male. Gad Enh. was noted in 76%. There were at initial diagnostic n(%)-at second interpretation n(%), respectively: astro. II 20(25)-4(5); astro. III 48(59)-3(3); oligoastro. II 2(2.5)-0; oligoastro III 5(6)-17(21); oligo. III 6(7)-22(27); glioblastoma mult. 0–20(25). According to the Sainte Anne classification, we observed: oligo. A 10(12); oligo. B 40(49); oligoastro. B 4(5); GBM 19(23). Discussion: These results show that the reproducibility of the WHO classification is low, as we already know. That could impact the decision of treatment the medical team will propose to the patients, and in some cases could lead to the wrong way. The long follow up of this study allows correlating with overall survival and de facto point out the discrepancy between prognostic factor and histology. Mature data will be presented at the congress. Conclusion: The new classification helped by IHC and imaging indisputably is more in concordance with recent prospective phase III data. P224*. THE IMPACT OF CHANGES IN PATHOLOGICAL CLASSIFICATION AND REFERRAL PATTERNS ON TREATMENT AND OUTCOME OF PATIENTS DIAGNOSED WITH A GLIOMA 1988–2002 S. C. Erridge1,2, G. R. Kerr2, M. Hart1, S. McNamara1, C. Smith1,3, R. Grant1, I. Whittle1,3, A. Gregor1,2; 1Edinburgh Centre for Neuro-Oncology, Edinburgh, United Kingdom, 2Edinburgh Cancer Centre, Edinburgh, United Kingdom, 3University of Edinburgh, Edinburgh, United Kingdom Introduction: This retrospective audit was conducted to examine the changes in patient characteristics, referral, treatment, and outcome over a fifteen-year period in a large center specializing in neuro-oncology, particularly focusing on the impact of the changes in WHO classification of gliomas. Methods: Using departmental database all cases referred to the Edinburgh Cancer Centre were identified, and patient, tumor and treatment characteristics noted and pathology records searched to confirm date of surgery and pathology. Survival was calculated from date of surgery or, if no operation performed the date of referral. Comparison was made between three periods 1988–1992 (C1), 1993–1997 (C2), 1998–2002 (C3). Results: 824 patients with glioma were referred during this period. The number referred increased by 50% from 229 in C1 to 344 in C3 (compared with 22% increase in Scottish Cancer Registry). Median age increased 53 to 57 yrs (p<0.001). The proportion without pathology remained unchanged at 10% (p=0.3), but the distribution of pathological grades changed G1-2: 25%, 7%, 5%, G3: 41%, 27%, 17% G4: 24%, 60%, 68% in C1, C2, C3, respectively (p<0.001). Immediate RT was given to 72% C1, 74% C2, 76% C3. Median interval from resection to RT reduced from 41days C1 to 34 days C3 (p<0.001). 5-year survival for G3 increased 19% C1, 34% C2, 39% C3. The 1-year survival for G4 also increased 18% C1, 26% C2, 29% C3. Both these improvements in survival over time probably reflect the change in pathological classification of GBM. In a proportional hazards analysis of G4 1993–2002 (to reduce pathological variation) younger patients, frontal lesions, excision, higher RT dose had reduced hazard of death. Delay from surgery to RT had no impact. Conclusions: There were significant changes in type of referral and in pathological classification reflected in the changing survival. The revised system appears a more accurate predictor. P225*. INTRACRANIAL TUMORS IN A COHORT OF NEUROFIBROMATOSIS I PATIENTS J. M. de Campos1, M. E. Kusak2, C. J. Klein1, J. Ayerbe1, A. del Villar3, J. L. Sarasa1; 1Fundacion Jiménez Diaz - Universidad Autónoma, Madrid, Spain, 2H Ruber Internacional, Madrid, Spain, 3HU Río Hortega, Valladolid, Spain Although neurofibromatosis type I (NFI) was initially described as peripheral neurofibromatosis, it is associated with tumors of the central nervous system in a higher frequency than random. These tumors are mainly gliomas, preferently seated on optic tract. The characteristics of brain tumors in NF1 patients have been scarcely analyzed. In the present study we revise the incidence, location, type and epidemiological characteristics of brain tumors diagnosed in a series of NF1 patients followed in a reference NF-clinic seated in a neurosurgical department. One hundred and seventy one patients have been diagnosed and followed for NF1 disease for a mean follow-up of 10 years. Patients were screened at least once with brain MRI study and only symptomatic and/or growing lesion were surgically biopsed or resected; entity diagnosis for other lesions were based on image and evolution characteristics. Twenty six from 171 patients showed optic/brain glial tumor. From these, 16 patients showed an optic glioma, 9 of them symptomatic but only 4 progressive. Fourteen patients showed a brain tumor out of optic tract, and four of these patients were affected from both and simultaneous optic and brain tumors. Mean age at diagnosis for optic glioma patients was 9.9 years, and 24.4 for brain tumor patients. Three brain tumors were malignant gliomas, two of them seated on the brain stem, and mean age was 29.3 years. Mean age for low grade brain glioma patients was 18.6 years, and the pathological picture for biopsed/resected low grade tumors was consistently a pilocytic astrocytoma. Two additional NF1 patients developed a vestibular schwannoma and a temporal fossa meningioma, respectively, and considered as incidental intracranial tumors not releted to the NF disease. NF1 patients are prone to intracranial glioma development, most of them optic gliomas, followed with pilocytic astrocytomas. Malignant gliomas, although more frequent than random, are rare. Optic gliomas are diagnosed in children, low-grade gliomas in young NF1 patients, and malignant gliomas in adults. P226. DOUBLE OR COLLISION POSTERIOR FOSSA TUMORS IN NF2 PATIENTS J. M. de Campos1, M. E. Kusak2, L. A. Vallejo3, J. L. Sarasa1, A. del Villar3; 1Fundación Jiménez Díaz - Universidad Autónoma, Madrid, Spain, 2H Rúber Internacional, Madrid, Spain, 3H. U. Río Hortega - Universidad de Valladolid, Valladolid, Spain Two tumors of discrete pathology occurring simultaneously and in close proximity to each other have been termed collision tumors. In Neurofibromatosis type 2 (NF2), both schwannoma sand meningiomas are present, and both are related to NF2 gene defect. We here present four events of collision or double tumors with schwannoma and meningioma components, in three NF2 patients operated on for four posterior fossa symptomatic tumors. In three cases the tumor was growing in ponto-cerebellar angle cistern, and the fourth one in the foramen magnum border. One of the patients, 69 years old, was operated on for a pontocerebellar mass that showed a bi-nodular mass during the surgery. The other two patients, 37 and 30 years old, had received 5 and 7 seven years before, respectively, stereotactic radiosurgery for vestibular schwannoma, that eventually progressed as multinodular tumors; a surgical resection was performed on these growing tumors and one of them on a consecutive foramen magnum bi-nodular tumor. In all four cases, histopathological study showed both meningioma and schwannoma pictures in separated fragments, keeping in mind that resections were performed rthough piece-meal fragmentation.A mixed tumor consisting of schwannoma and meningioma components is very rare, with only 13 cases reported before. Posterior fosas atumors in NF2 patients can have a double neoplastic tissue components, schwannoma and meningioma. This fact should be kept in mind before planning surgical or radiosuregical treatments for these patients. The origin of these double or collision tumors could be favored by the germinal NF2 gene lesion in all cells of the patient, with the eventual addition of a second hit on the other NF2 allele in both, arachnoidal and schwann neighbor cells. A possible role of radiosurgery in increasing the spontaneous prone development of schwannomas and meningiomas in NF2 patients can be considered. P227. RESULTS OF A SERIES OF 147 PATIENTS WITH GLIOBLASTOMA OLDER THAN 65 YEARS Á. Oszvald, V. Seifert, K. Franz; Neurosurgical Clinic, Frankfurt am Main, Germany Objective: To analyze whether elderly patients with glioblastoma can cope with the same aggressive treatment as younger patients and whether it effects the survival time. Methods: The data for this study derive from a large prospectively conducted database of cerebral gliomas with regular follow up from diagnosis to death. 370 patients (male/female; 215/155) with histopathological confirmed diagnosis of glioblastoma from 2000 to 2006 were included. Regardless of age all patients underwent complete or partial resection or biopsy. After the surgical treatment all patients underwent either radiation, chemotherapy or combined treatment and further therapies, if needed. The cut off age for elderly patients was 65 years. Results: The overall survival after resection or biopsy in older patients (mean age 71 years) was significantly lower than in younger patients (mean age 57 years) (p<0.0001). Analyzing the subgroup of patients with at least partial resection no difference in survival time between elderly and younger patients could be found (p=0.67). In contrast, elderly patients that underwent biopsy and further adjuvant therapy had significant shorter survival time (p=0.007). Conclusions: Our current data show that resection to the extent feasible, followed by adjuvant therapies, in elderly patients with glioblastoma is warranted. Therefore, regardless of age these therapeutic options should be standard for all patients in good clinical conditions. P228. MANAGEMENT OF HIGH-GRADE GLIOMAS IN THE ELDERLY: A RETROSPECTIVE COHORT STUDY A. Rodríguez-Hernández, I. Arrese, M. Armendariz, A. Bollar, P. Torres, I. Ruiz, M. Arrazola, N. Samprón, E. Urculo; Hospital Donostia, San Sebastian, Spain Background: Malignant gliomas represent more than 80% of intracranial tumors in the elderly and, according to several recent studies, an increasing proportion of patients with gliomas in the near future will be in this group of age. Predominantly glioblastoma histology with invariable fatal outcome, disabling comorbidities and presumed low tolerability of surgery and adjuvant treatments are the main reasons why elderly patients have been under-represented in most of clinical trials. So, the balance of benefits and side effects of surgical resection and radiochemotherapy versus more conservative treatments remains controversial. Patients and Methods: We have retrospectively analyzed the cohort of patients histopathologically diagnosed of high-grade gliomas in our hospital from Jan/1996 to Dec/2006, comparing the prognosis of patients aged 65 years or more with younger patients. Sex, type of surgery, tumor grade, Karnofsky performance status, and adjuvant treatment were analyzed using multivariate method. Results: 200 patients were diagnosed of high-grade glioma, being 71 the cases aged 65 years or more. The surgical morbid-mortality was higher in elderly patients, but this difference was not significative when adjusting by clinical conditions. Long term prognosis of elderly population was also poorer, but surgical and adjuvant treatments were more conservative in older patients. Conclusions: The optimal treatment of elderly patients with high-grade gliomas has not been determined and, in our study, this population was undertreated when compared to younger patients. Further prospective studies should be designed to delineate clarifying profile of elderly patients who would obtain benefit of an aggressive treatment both in terms of quality and quantity of life. P229*. THE GLIOBLASTOMA MULTIFORME OF THE ELDERLY: THE PROGNOSTIC IMPACT OF RESECTION ON SURVIVAL M. Goeppert, W. Stummer, H. Steiger, M. Sabel; Department of Neurosurgery, Duesseldorf, Germany Objective: According to recent developments the best treatment options for glioblastoma (GBM) patients consist in maximal safe resection and additional adjuvant treatment with radiotherapy (RT) and alkylating chemotherapy (CHX). These options have been evaluated for populations with a median age of approximately 58 years. We therefore addressed the issue whether elderly patients (>65 y) could also benefit from cytoreductive surgery (CS) and adjuvant treatment using alkylating chemotherapy. Method: 96 patients (>65 y, median 70.7 y) diagnosed with primary GBM (resection or biopsy) were retrospectively divided into group A (n=29) treated with surgery alone (Biopsy, B, n=17, CS n=12), group B (n=36) surgery and radiation (B n=18, CS n=18) and group C (n=31) surgery, RT and Chx (B n=4, CS n=27). Progression free survival (PFS) and overall survival (OS) were determined in each group and correlated to age, Karnofsky performance score (KPS), and extent of resection (biopsy [B], partial [PR] and complete resection [CR], respectively. Results: For the whole population PFS and OS were 3.6 m and 5.6 m, respectively. PFS and OAS for groups A/B/C were 2.2m/3.7m/7.3m (p=0.00) and 2.2m/5.1m/13.9m (p=0.00), respectively. Median age for groups A/B/C was 73.1y/70.6y/68.5y and median KPS was 60/70/80. Age (<75, >75) was correlated with OS (6.4 m / 3.2 m, p=0.01). KPS (<70, >70) was correlated with PFS 2.5 m/3.9 m (p=0.006) and OS 3.3 m/7.1 m (p=0.000). Extent of resection (biopsy, PR and CR) correlated with PFS (2.4 m/3.6 m/8.8 m, p=0.001) and OS (2.5 m/7.0 m/13.6 m, p=0.001), respectively. Conclusions: Our study clearly demonstrates that elderly GBM patients benefit from aggressive treatment protocols including cytoreductive surgery, radiation therapy, and chemotherapy. Treatment decisions in this population are obviously influenced by KPS and age. The most impressive outcome predictor in this population was the extent of surgical resection. In summary elderly GBM patients should not be per se excluded from intensive treatment protocols. P230. LOMUSTINE (CCNU) AS AN ALTERNATIVE OF TEMOZOLOMIDE IN ELDERLY PATIENTS WITH GLIOBLASTOMA G. Kaloshi, A. Rroji, R. Alimehmeti, M. Petrela; UHC, Tirane, Albania Background: Upfront temozolomide is the most often proposed treatment for elderly patients as an alternative to radiotherapy (RT). However, due to its expensive cost, this treatment is not available in Albania. Consequently, other chemotherapy regimens are proposed to such patients. We analyze here a cohort of elderly patients with high-grade glioma treated with CCNU alone. Methods: We retrospectively reviewed all elderly patients (age>65 years) from our institution with glioblastoma who received upfront chemotherapy by CCNU (110mg/m2/day every 6 or 8 weeks). Results: Five eligible patients (mean age 72 years, [range 67–79], mean KPS 70 [range 50–80], all histologically proven glioblastomas) were treated with oral CCNU for 1–6 cycles (mean = 4). Median overall survival (OS) and median progression free-survival (PFS) were 30 weeks and 17 weeks, respectively. One grade IV hematotoxicity was observed. No death related to the treatment was observed. Conclusion: The survival of CCNU treated patients seems comparable to the TMZ regimen or to radiotherapy. Due to its good tolerance profile, further studies are needed to better evaluate the benefit of CCNU in the elderly in the lack of standard therapies. P231. CHEMOTHERAPY FOR MALIGNANT GLIOMAS WITH POSITIVE MGMT PROTEIN EXPRESSION: EXPERIENCE OF 51 CASES J. Zhang, Z. Chen; Cancer Center, Guangzhou, China Purpose: To compare the efficacy and toxicity of three chemotherapy regimens. Methods: Fifty-one patients with histologically confirmed malignant gliomas and MGMT positive expression were enrolled in this study. The glioma tissues were examined for MGMT protein expression by immunohistochemistry. The patients were treated with: 1, regimen contained of nitrosourea (nitrosourea group) 11 cases; 2, regimen contained of temozolomide (temozolomide group) 18 cases; regimen contained of neither nitrosourea nor temozolomide (no alkylating agent group) 22 cases. Response to chemotherapy was evaluated according WHO criteria, and toxicity was evaluated according National Cancer Institute (NCI) criteria. Results: The overall objective response rate (CR+PR) for 51 cases with MGMT position gliomas was 20%, and disease control rate (CR+PR+SD) was 59%. The objective response rates and disease control rates in nitrosourea group, temozolomide group, and no alkylating agent group were 0%, 18.2%, 16.7% and 61.1%, 31.8%, 77.3%, respectively. There was significant difference between no alkylating agent group and nitrosourea group (P<0.05). Hematological toxicity and nausea/vomiting were main side-effects observed in nitrosourea group. While there was comparative lower incidence of side-effects in temozolomide group. Hematological toxicity, nausea/vomiting, and alopecia were main side-effects observed in no alkylating agent group. Though there was higher incidence of 3–4 grade hematological toxicity in this group, but it could recovered by oneself in one week or through treatment with G-CSF for 3–5 days. Conclusion: Regimen contained no alkylating agent group can obtain higher response rate and thus is worth of recommending to patients with MGMT positive gliomas. However, because of a modest response rate and good toleration, regimen with temozolomide should not be given up in MGMT position gliomas. Nevertheless, It is necessary to discover more efficiency way of using temozolomide. Nitrosourea should not be recommended to MGMT position glioma patients. P232*. BIODEGRADABLE CARMUSTINE-IMPREGNATED WAFERS (GLIADEL): THE FRENCH EXPERIENCE P. Menei1, P. Metellus2, H. Loiseau3, L. Capelle4, G. Jacquet5, J. Guyotat and the club of neuro-oncology of the FSN6; 1CHU d' Angers, Angers, France, 2Hopital de la Timone, Marseille, France, 3Hôpital Pellegrin Tripode, Bordeaux, France, 4Hôpital Pitié Salpétrière, Paris, France, 5CHU de Besançon, Besançon, France, 6Hôpital Neurologique, Lyon, France Introduction: Gliadel was registered in France in 1998 for treatment of recurrent glioblastoma (GB) by implantation in the resection cavity. In early 2005, this was extended to primary malignant glioma (MG). Recently, a standard regimen (Stupp protocol) of radiochemotherapy (RCT) with concomitant and then monthly Temodal (TMZ) was shown to prolong survival vs. radiotherapy (RT) alone in pts with primary GB. There are currently no standards for combining Gliadel and RCT with TMZ. Methods: A prospectve, open-label, multicenter study was conducted in 26 French neurosurgery departments to evaluate adding Gliadel to standard treatment regimens for GB and MG. All pts on study received Gliadel. Results were compared with those of previous phase III studies in terms of adverse events (AEs) and survival. Results: A total of 163 pts were included; 83 (51%) with primary MG, and 80 (49%) with recurrent MG. For 72.5% of pts with recurrent MG, Gliadel was employed as a second-line therapy. Median age was 60 and 52.5 years for the primary and recurrent groups, respectively, and median Karnofsky Performance Score (KPS) was 80 in each group. For primary MG, 51.8% of pts received standard RCT with TMZ. The remaining 48.2% of pts received RT or chemotherapy (CT) as follows: RT (31.3%), radiosurgery (2.4%), no RT (14.5%), nonstandard TMZ (6%), other systemic CT (7.2%), or no CT (34.9%). AEs were reported for 44.6% of pts, including 6% with septic abscesses. The AE rate was not statistically correlated with Gliadel or with RCT with TMZ. Median survival for pts with primary disease was 76.8 weeks. Prognostic factors included extent of resection and use of adjuvant RT. Univariate analysis showed that extent of resection and adjuvant RT but not the addition of systemic CT were associated with survival. After adjusting for these factors, survival benefit was observed in pts treated according to the Stupp protocol. For pts with recurrent MG, postoperative treatments in addition to Gliadel were: conventional RT (20%), systemic CT (32.5%), or standard RCT with TMZ (12.5%). Median survival in pts was 34.1 weeks, and extent of resection and KPS were strong prognostic factors. Conclusions: Improved overall survival was observed with the combination of Gliadel and TMZ compared with previously published phase III studies. This regimen was well-tolerated without additional adverse effects. P233. THALAMIC MALIGNANT GLIOMAS: A CLINICOPATHOLOGICAL ANALYSIS OF 19 CASES WITH REFERENCE TO MR IMAGING J. Hwang, S. Hwang, Y. Park; Department of Neurosurgery, School of Medicine, Kyungpook National University, Daegu, Republic of Korea Malignant gliomas of the thalamic region constitute approximately 1–5% of intracranial tumors, and the treatment outcome is still dismal due to their deep seated, midline location. We retrospectively reviewed the clinical record and MR imaging of the patients with histologically proven malignant gliomas in the thalamus. The study group included nineteen patients (ten men, nine women; mean age, 39.7 years; range 9–61 years). Headache (17, 89.5%), blurred vision/diplopia (10, 52.6%) and motor weakness (7, 36.8%) were the common presenting symptoms. Mean symtpom duration was 9.3 weeks. Based on MR imaging, growth pattern of tumor was diffuse bulging type in 8 patients, exophytic in 7, and combined in four. The histological diagnosis was diffuse astrocytoma in 5 patients, anaplastic astrocytoma in 7, and glioblastoma in 7; three patients with astrocytoma showed dedifferention to anaplastic astrocytoma during follow-up (mean transformation time, 18.7 weeks). The growth pattern of tumor on MR showed good correlation with histologica grade. The initial surgical treatment was stereotactic biopsy in 6 patients, open biopsy in 5, partial resection (>50% of tumor volume) in 3, and subtotal resection (>90% of tumor volume) in 5. Radiotherapy followed by chemotherapy in 8, concurrent chemoradiotheray in 2, and radiation only in 5. Six patients needed shunt operation. Sixteen patients (84.2%) showed tumor progression and mean time to tumor progression (TTP) was 20.1 weeks (range 7–100 weeks). Subtotal tumor resection was performed in 7 patients in total with acceptible morbidity during follow-up period. The extent of surgical resection was favorable prognostic factor for TTP. Mean survival was 81.6 weeks (range 2–189 weeks). In univariate analysis, histological grade and tumor growth pattern on MR were significant prognostic factors for survival. Thalamic malignant gliomas have a poor prognosis, despite multimodal treatment. Maximum microsurgical resection may be helpful in selected patients with exophytic tumor growth pattern. P234. GLIOBLASTOMA WITH OLIGODENDROGLIAL COMPONENT: ANALYSIS OF 36 CASES M. Salvati1, C. Brogna1, A. d`Elia1, A. Melone1, J. Lenzi1, A. Frati1, A. Santoro1, V. Esposito2, F. Giangaspero1,2, R. Delfini1; 1Neuroscience-Neurosurgery Department, Sapienza University, Rome, Italy, 2Neurosurgery Department, INM Neuromed IRCCS, Pozzilli, Isernia, Italy Background: Glioblastoma multiforme (GBM, grade IV WHO) is the most malignant glial tumor, and despite treatment overall survival (OS) still remains poor. On the last decade it has been noticed that not all GBM develop the same clinical course, and that different prognostic classes may arise from different morphologic and genetic profiles. One important feature is morphology, particularly through the observation of foci within GBM samples that resemble oligodendroglioma. Materials and Methods: 450 patients affected by histologically proven supratentorial cerebral glioblastoma (GBM, grade IV according to WHO) were treated at our institutions from January 2002 to December 2006: all patients received at least subtotal surgical removal, followed by the same standard radio- and chemotherapy as adjuvant treatment. In a subgroup of 36 cases (8.0%) among these, an oligodendroglial component was observed. Molecular assessment of these cases was performed, and LOH for 1p, 19q and 10q, EGFR amplification and TP53 gene expression was determined. Mean follow-up was of 16.1 months, ranging from 10.5 to 44.5 months. Results: Median age of this group of patients was 52.1 years (range: 38–68 years), vs. 56.4 years of the entire GBM population. Chromosome analysis of this subgroup of patients resulted as follows: LOH 1p and/or 19q in 27 cases (75.0%), LOH of 10q 21 cases (58.1%), EGFR amplification resulted in 14 cases (39%), and TP53 mutation resulted in 8 patients (22.2%). Overall survival (OS) was 28 months vs. 15.2 years for the entire GBM population, and progression-free survival (PFS) was 20.4 months vs. 13.6 months for the entire group. 2-year survival was 55%. Conclusions: The presence of an oligodendroglial component in GBM appears to be an important prognostic feature to which is related a better prognosis, that resemble more that of anaplastic oligodendrogliomas. No particular molecular features were observed, except LOH of 1p and 19q, that was significantly associated with GBM with oligodendroglial component. P235. MULTIDISCIPLINARY APPROACH TO SUPRATENTORIAL CEREBRAL GLIOBLASTOMA: PERSONAL EXPERIENCE ON A SURGICAL SERIES OF 450 CASES M. Salvati1, C. Brogna1, A. Melone1, A. D`elia1, V. Donato2, V. Esposito3, A. Santoro1, F. Giangaspero1,3, R. Delfini1, G. Cantore3; 1Neuroscience-Neurosurgery department, Sapienza University, Rome, Italy, 2Radiotherapy, San Camillo Hospital–Rome, Italy, Rome, Italy, 3Neurosurgery Department, INM Neuromed IRCCS, Pozzilli, Isernia, Italy Materials and Methods: 450 patients affected by histologically proven supratentorial cerebral glioblastoma (GBM grade IV according to WHO) were treated at our institutions from January 2000 to December 2006 (mean age: 56.4 years, range 16–83). In this series we included all patients with a Karnofsky Performance Status (KPS) > 60 and who received at least subtotal surgical removal. Molecular assessments were performed, and EGFR, PTEN gene, and p53 expression was defined. In 110 cases the MGMT-enzyme expression was defined by evaluating the methylation status of the relative promoter gene, and YKL-40 protein expression was evaluated by immunohistochemical technique. With the aim of parallel two different adjuvant regimens, we retrospectively compared two groups of patients: the first group of 83 patients was treated with postsurgical adjuvant conformational radiotherapy (with a mean of 60 Gy delivered in 30 fractions) alone, followed by a mean of 12 cycles of adjuvant temozolomide (TMZ), administered 5 days every 28, 200 mg/m2 of body surface; the second group of 367 patients received concomitant radiotherapy (with a mean of 60 Gy delivered in 30 fractions) and TMZ chemotherapy with 75 mg/m2 of body surface, administered one hour before every radiotherapy fraction, followed by the same adjuvant TMZ-based regimen, administered 5 days every 28, 200 mg/m2 of body surface for a mean of 12 cycles. 38 patients (8.4 %) manifested important hematologic toxicity: for 20 of these (52.6%) toxicity was limited to platelet series. In three cases hematologic toxicity determined interruption of the treatment and modification of the chemiotherapeutic regimen. Results: Mean overall survival (OS) was 15.2 months, with a PFS of 13.6 months. Mean survival of the subgroup of patients with a methylated MGMT gene promoter, YKL-40 protein not expressed and that underwent a reoperation with at least subtotal removal was 26 months. MGMT enzyme and YKL-40 expression were related to a poorer prognosis. Moreover, in a subgroup of 36 cases (8.0%) in which an oligodendroglial component was observed, mean survival was 28 months with a 2-year survival of 55%. Conclusions: OS and particularly progression-free survival (PFS) were significantly higher in patients with these characteristics: age<45 years, KPS>80, surgical removal of the lesion>98%, even at reoperation, MGMT not expressed (a methylated promoter of the gene), YKL-40 protein not expressed, and concomitant radio- and chemotherapy as adjuvant treatment. P236. TREATMENT AND SURVIVAL OF GLIOBLASTOMA PATIENTS IN SLOVENIA, 1997–2006 U. Smrdel, A. Secerov; Institute of Oncology Ljubljana, Slovenia, Ljubljana, Slovenia Glioblastoma multiforme (GBM) accounts for around 0.5% of all patients treated for malignant disease in Slovenia. Each year there are 40 to 50 new patients diagnosed with GBM. We revived treatment and survival data for patients treated between 1997 and 2006. 424 Patients with GBM were reported. All patients were revived at the Institute of Oncology in Ljubljana. All but one patient had the diagnosis of GBM histological confirmed, and half of patients have had tumor macroscopically removed. 337 patients received postoperative radiation therapy while others received symptomatic treatment. Most of the patients received no chemotherapy (292/424), 61 received concomitant chemo radiotherapy followed by adjuvant chemotherapy with temozolomide, and 70 patients received other types of chemotherapy. Survival was significantly longer in patients younger than 50 years and in patients receiving concomitant chemo-radiotherapy followed by adjuvant chemotherapy with temozolomide. In multivariate analysis the other important prognostic factor was performance status, while the extent of operation proved not to be of significance. While the increase of overall survival, though significant, remained modest, the increase in population of younger patients who received concomitant chemo-radiotherapy followed by adjuvant chemotherapy with temozolomide is marked. P237*. QUANTIFYING ASSESSMENTS FOR GLIOBLASTOMA MULTIFORME (GBM) FOR CLINICAL TRIALS —AN ALTERNATIVE APPROACH G. Dresemann1, G. Sorenson2, D. A. Reardon3, C. Hosius4, R. Parker5, Z. Nikolova5; 1CTC-Standort Franz-Hospital, Dülmen, Germany, 2Massachusetts General Hospital, Charlestown, MA, United States, 3Duke University Medical Center, Durham, NC, United States, 4Novartis Pharma Oncology, Nürnberg, Germany, 5Novartis Pharma Oncology, Basel, Switzerland Background: MacDonald et al. (1990) combined review of tumor imagery (e.g., MRI/CT scans), with neurological and steroid information for tumor assessment of patients with GBM in clinical trials. Completion of a randomized phase III clinical trial comparing Imatinib (I) plus Hydroxyurea (HU) vs. HU alone, as well as interim reviews of other GBM trials, demonstrated key differences between investigator and central independent review (CIR) results, and the impact of steroids within the assessment. The inclusion of a CIR team in clinical trials is ensuring consistent, high quality data when CIR teams and investigators follow and interpret assessments in a similar manner. Discussion: When using the MacDonald criteria, sensitivity analyses of progression free - (PFS) and overall survival (OS) highlighted strong similarity between the site assessment and the CIR data excluding steroids. When the same review was conducted including steroid information, site and CIR response data were markedly different. CIR review adopted a strict algorithmic approach, which was closely matched when reproducing the results programmatically. Where possible, the same methodologies as outlined in other key clinical trials were adopted, but evidently, different emphasis was placed on different aspects: MRI frequency, and the impact of steroid and neurological information varied. The discrepancy between sensitivity and specificity of neurological and/or steroid dose assessment for determination of progressive disease (PD) especially within the first 2 months after starting a new treatment is well known. Alignment and appropriate consideration of practicalities is required to permit uniform assessment across different therapies in the treatment of GBM. This will be of use to regulators, physicians, and the pharmaceutical industry as a whole. Recurrent GBM remains an unmet medical need. A comprehensive review of the impact of different ways of handling steroid, MRI, and neurological assessments was performed in relation to assessment of recurrent GBM using the MacDonald criteria. Modifications to the existing criteria are suggested to increase the specificity of assessments performed. Conclusions: Evaluation of neurological, steroid, and MRI assessments should be conducted within the same time window—initially at 4 weekly (at least first 3 months), later on at 8 weekly intervals. These intervals can be easily mapped onto each other for comparison purposes and provide a good compromise for fluctuation around the world of different timeframes in standard of care treatments. Neurological and steroid assessments should be used as preliminary-factor in determination of PD during the first 2 months of assessment to be confirmed or corrected by following clinical/neurological, steroid, and MRI assessment. Especially the influence of dexamethasone on ventral upper leg muscles must be taken into consideration. P238. LONGITUDINAL IMPROVEMENT OF PROGNOSIS IN GLIOBLASTOMA PATIENTS BY CHANGES IN SURGICAL AND ADJUVANT THERAPY: A SINGLE-CENTER DATABASE ANALYSIS P. Slotty, W. Stummer, M. Goeppert, H. Steiger, M. Sabel; Department of Neurosurgery, Duesseldorf, Germany Introduction: Throughout the past years the primary therapy of glioblastoma has changed due to the introduction of ALA-fluorescence guided resection and concomitant radiochemotherapy according to the Stupp scheme. The impact of these modifications on the prognosis of glioblastoma patients were subject of this analysis. Methods: Since 2003 epidemiological and clinical data on glioma patients have been collected in the Neurooncological Database of our department. For the present analysis 231 surgically treated primary glioblastoma patients from the years 2003 to 2006 were stratified by operation with or without ALA and adjuvant therapy with or without concomitant therapy. Results: Overall survival appeared to improve over the years 2003 to 2006 (10.1 vs. 14.5 months, p=0.117). Patients without fluorescence-guided resections or concomitant radiochemotherapy had a median survival of only 6.3 months, those with fluorescence-guided resection and adjuvant radiotherapy 11.5 months, and patients treated with fluorescence-guided resections and adjuvant concomitant radiochemotherapy 16.7 months. Groups were not quite balanced regarding age and pre-surgery Karnofsky Performance Score (KPS). Conclusions: Due to changes in treatment overall survival in patients with primary glioblastomas has improved in the last years. Fluorescence-guided resections and adjuvant radiochemotherapy according to the Stupp scheme seem to have additive effects. However, a selection bias in these series cannot be ruled out due to the misbalances in age and pre-surgical KPS. P239. GLIOBLASTOMA WITH EXTRANEURAL METASTASES M. E. Loghin, D. Suki, M. A. Hatiboglu, G. N. Fuller, F. DeMonte; M.D. Anderson Cancer Center, Houston, TX, United States Background: Extraneural metastases of glioblastoma multiforme are rare and usually occur in the context of recurrent intracranial tumor. Here we present a small series of patients with metastatic glioblastoma. Methods: Through an IRB-approved, retrospective chart-review, spanning 1955–2006, we identified 9 patients with glioblastoma and extraneural metastases. Clinicopathological findings are reported. Results: Median age at the time of primary diagnosis was 49 (15–59 years); two patients were under the age of 20. All patients received surgical resection of the tumor (n=1–3) and one patient had a ventriculo-peritoneal drainage. Five patients developed extraneural metastases within 6 months from their initial tumor resection. Six patients died within 2 years of diagnosis and one patient is still alive and undergoing systemic chemotherapy. At the time of death, 3 patients had apparent tumor control at their primary site. Direct tumor growth leading to extracranial tumor manifestations, all on the same side, occurred in 4 patients. Distribution of distant metastases was as following: lung (n=2), liver (n=1), lymph nodes (n=2), parotid gland (n=1), and bones (n=3). One patient developed neoplastic meningitis, as well. Histopathology was consistent with de novo glioblastoma in 7 cases and secondary glioblastoma in 2 cases. Two patients had a gliosarcomatous transformation at the time of their local recurrence. Two of 9 patients had TP53 mutations. In two cases, the primary and metastatic tumor had identical genotype. Conclusions. The present case series demonstrates that metastatic glioblastoma tend to occur in younger adults, following neurosurgical procedures. Further analysis and identification of molecular alterations may aid in the early diagnosis and targeted treatment of glioblastoma with metastatic potential. P240. GLIOBLASTOMA MULTIFORME OUTCOME AFTER BIOPSY J. Marruecos, E. Verger, N. Viñolas, L. Caral, T. Pujol, T. Ribalta, F. Graus; Hospital Clínic de Barcelona. Brain tumors group, Barcelona, Spain Introduction: Glioblastoma multiforme (GBM) is the most common malignant primary brain tumor in adults. It is often fatal, as conventional multidisciplinary treatment approaches have limited efficacy. Median survival time (MST) of patients is poor. When biopsy is the only surgical procedure prognosis is worse. Surgical debulking approach is frequently not feasible because of poor Karnofsky (KPS), or anatomical limitations such as multicentricity and involvement of eloquent areas or corpus callosus. Objectives: This review aimed to analyze the outcome in GBM patients with cerebral biopsy-only surgical procedure and postoperative radiotherapy (RT). Material and Methods: We evaluated clinical characteristics and outcome of 52 of 151 consecutive patients with GBM treated in our institution between 1999–2004, in whom debulking surgery was not feasible and biopsy was the only surgical procedure realized. Results: Biopsy was the only surgical procedure in 34.4% (52 of 151) of the patients with GBM. 19 of those 52 patients did not receive further treatment due to bad KPS (63.2% KPS ⩽ 50) or rapid clinical impairment. 33 patients were treated with postoperative RT. Mean age was 54.6 years (23–73). Only 4/33 patients that started radiotherapy did not finish it; 3 because of tumor progression during treatment and one due to hepatic vein thrombosis. 88% of patients (n=29) completed the treatment as prescribed. Radiological response one month after finishing radiation therapy was 14 progressions (PG), 2 partial responses (PR), and 9 stabilizations (ED). 4 patients did not have a radiological assessment due to rapid deterioration. MST in patients who underwent biopsy was 141 days (74–208 days); with a MST of 75.7 days for those not treated and 299 days for those who were. Conclusions: 1/3 of patients with GBM undergo a biopsy as the only surgical procedure. Outcome in the biopsy only group is poor. In our series, patients that received further treatment had a longer MST (MST 10 months vs. 2.5 months). 88% of patients who started treatment were able to finish it. Despite poor prognosis in this group of patients, individualized treatment may prolong survival. P241. TIME TO RECURRENCE IN PATIENTS WITH MALIGNANT GLIOMA DEPENDING UPON THE CONCOMITANT USE OF ANTICONVULSANTS AND CHEMOTHERAPY M. Molina-Garrido1, C. Guillen-Ponce1, M. Guirado-Risueño1, A. Mora2, M. Molina1, M. Molina1, A. Carrato1; 1Medical Oncology, Elche (Alicante), Spain, 2Internal Medicine, Elche (Alicante), Spain Background: Commonly, glioma patients are treated with enzyme-inducing antiepileptic drugs (EIAEDs). Patients receiving EIAEDs show decreased plasma levels of several chemotherapeutic drugs when administered at conventional doses. Induction of hepatic enzymes by EIAEDs can alter the metabolism of concurrently administered chemotherapeutic agents, which might lead to ineffective dosing. The primary objective of the current study was to determine the time to tumoral recurrence in patients with malignant glioma treated with chemotherapy that are taking concomitant anticonvulsants. Secondary objectives were to determine which factors could influence the time to tumor progression. Methods: Twenty-four patients with high-grade cerebral gliomas were retrospectively examined between December 2003 and June 2007. Age, sex, kind of tumor, localization of tumor, type of treatment, tumor recurrence, and EIAEDs were evaluated. Results: From January 2003 to June 2007, 24 patients were diagnosed of high-grade glioma. 50% were women. Median age: 47.67 years. 50% anaplastic astrocytoma. Tumor localization: temporal (40.9%), parietal (36.4%); right cerebral lobe (59.1%). 81% of all them took phenytoin as antiseizure drug, alone or together with another medication. Surgery was radical in 45.8% of cases. 70.8% took at least radiotherapy and 73.9% of all them, chemotherapy. The most frequent antitumoral medication as front therapy was temozolomide (94.12%). 80% of all patients had at least one first tumoral recurrence (median 7.3 months). After a second recurrence, just 6.7% of patients followed palliative symptomatic treatment. At the end of the analysis, 83.3% of patients had died; median overall survival: 17.02 months. Regression analysis of time to recurrence (p=0.001): age (p=0.001), sex (p=0.975), pathology (p=0.662), radicality of surgery (p=0.698), radiotherapy (p=0.963), kind of chemotherapy (p=0.956), tumoral localization (p=0.951), kind of antiseizure drugs (p=0.977). Conclusion: In this study, overall survival is higher than in other series. Recurrences take account very early (median 7.3 months) and they are actively treated in 93.7% of all cases. Age is the only factor that influences tumor recurrence significantly (sex, pathologic type, kind of chemotherapy or tumoral localization do not). P242. SUPRACHIASMATIC EXTRAVENTRICULAR CHORDOID GLIOMA P. P. Molnár1, S. P. Barla2, D. Nagy2, G. Nagy3, E. Berényi4, J. Dobai2; 1University of Debrecen, Medical and Health Sci. Ctr. (UD-HMSC), Dept. Pathology, Debrecen, Hungary, 2B-A-Z County Hospital, Dept. Neurosurgery, Miskolc, Hungary, 3B-A-Z County Hospital, Dept. Radiology, Miskolc, Hungary, 4University of Debrecen, Medical and Health Sci. Ctr. (UD-HMSC), Dept. Radiology, Debrecen, Hungary Aim: Chordoid glioma is a rare, intraventricular tumor of which by March 2008 a total of 43 cases have been reported. The authors wish to present a case of an extraventricular, suprachiasmatic tumor with features of a chordoid glioma that seems to be the first cases presenting intraoperatively as an optic glioma. Case Report: The 34-y-old female patient had had visual symptoms, nausea, ataxia and headaches for 1 month prior to her surgery. CT showed a 30 × 40 × 15 mm large tumor that was homogeneously hypodens. MRI T1 sequences were of low-, T2 sequences of high intensity, and the tumor enhanced inhomogeneously. The tumor was somewhat infiltrative. Neurosurgically the lesion seemed to have arisen from the optic chiasm. Radical removal was not feasible and the patient eventually died of circulatory failure among septic conditions. Pathology: Rather monomorphous, ovoid, or polygonal cells with moderate amount of eosinophilic cytoplasm were embedded in a microvacuolated, mucinous stroma. The cells formed cords and islands, the nuclei had salt-and-pepper chromatin. Mitoses were rare, necrosis was absent, and focal endothelial proliferation and hemorrhages were observed. Most of the cells were GFAP and S-100 positive with focal, ambiguous EMA reactivity. CEA and panCK were negative. Mib-1 LI was < 1%, and EGFR reactivity was present in a heterogeneous distribution with 1+ intensity. Discussion and Conclusion: The clinical assumption of a craniopharyngeoma could be discarded, the classical features of optic gliomata were not present. The histo- and cytomorphology as well as the immunohistochemical profile were congruent with those described for chordoid glioma. We could not confirm ependymal differentiation of the tumor. Detailed neuroradiological and pathological documentation is presented. To the best of the authors' knowledge (Google Scholar search) no prior report of a chordoid glioma that was intimately adhered to the optic chiasm and did not cause hydrocephalus has been as yet described. This case calls attention to a rather unexpected differential diagnostic aspect of juxtasellar neoplasms. The exact histogenesis of chordoid gliomas awaits further clarification. P243. A SYNCRONOUS MENINGIOMA AND GLIOSARCOMA WITH LONG SURVIVAL P. Linhares1, O. Martinho2, J. Lopes1, R. Vaz1, R. Reis2; 1Hospital São João/Faculty of Medicine, Porto, Portugal, 2Health Sciences Institute, Braga, Portugal Gliosarcomas are rare variants of glioblastoma characterized by a biphasic tissue pattern with alternating areas displaying glial and mesenchymal differentiation. The clinical presentation and the biologic behavior are similar to glioblastoma with a median survival of less than approximately 1 year. In the present study we report a unique case of a long survival primary gliosarcoma (32 months) with a synchronous meningioma. In order to determine tumor clonality and assess the biological nature of such long survival we perform an immunohistochemical and molecular characterization of the two lesions. A 51-year-old woman underwent a right frontal with complete excision of the two tumors, a meningioma (located in the interhemispheric cysure) and a gliosarcoma (located in the posterior region). Patient was submitted to radiotherapy in the location of the gliosarcoma remaining asymptomatic for the next 20 months, where the patient exhibited clinical and imagiological signals of recurrence. Following a second craniotomy with complete removal of the gliosarcoma recurrence, the patient started temozolomide-based chemotherapy. After recovering from the neurological deficits, the patient showed progressive symptoms of deterioration confirmed by imagiological tumor re-growth, leading to death 12 months later. MGMT was assessed by immunohistochemistry and methylation status. MGMT methylation was observed in all 3 tumors, confirmed by loss of immunoreactivity in neoplastic cells. The mutation analysis of tumor suppressor gene TP53 and oncogenes BRAF and PIK3CA showed the absence of any mutation in any tumor. The EGFR analysis showed the absence of overexpression and gene amplification in both primary gliosarcoma and meningioma, whereas gliosarcoma recurrence showed strong positivity and concomitant gene amplification. Analysis of COX2 immunohistochemistry depicted overexpression in the meningioma tumor and absence in both primary and recurrence gliosarcoma. In conclusion, we report for the first time the occurrence of synchronous meningioma and gliosarcoma. We observed the absence of mutations in TP53, BRAF, and PIK3CA genes. MGMT methylation was present in all 3 malignancies, which could in part explain the good prognosis. EGFR gene overeexpression/amplification was present only in the recurrence, supporting its association with tumor aggressiveness. COX2 frequently associated with meningioma neoplasms was observed only the meningioma tumor. P244. THIRD VENTRICULAR GLIOSARCOMA ASSOCIATED WITH NEUROFIBROMATOSIS TYPE I: CASE REPORT J. Hwang1, Y. Sohn2, S. Hwang1; 1Department of Neurosurgery, School of Medicine, Kyungpook National University, Daegu, Republic of Korea, 2Department of Pathology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea We describe a very rare case of third ventricular gliosarcoma with neurofibromatosis type I (NF I). A 45-year-old man presented with aggravating headache, urinary incontinence, and gait disturbance for 3 weeks. Multiple neurofibromas over whole body with many cafe au lait spots had been presented since early childhood. Neuroradiological studies revealed a large solid mass in posterior third ventricle and remarkable ventricular enlargement. The mass showed sharply demarcated high intensity with Gd-DTPA enhancement. Tumor staining on angiography revealed that the blood supply was predominantly from medial posterior choroidal arteries. The tumor was sucessfully removed via an anterior transcallosal transchoroidal approach. The mass was composed of central hard, peripheral soft friable portion and the demarcation was obscure in the deep lateral part. Histological examination disclosed gliosarcoma with epitheloid differentiation. Tumor tissue stained positively with trichrome, reticulin, and GFAP. We could not find subarachnoid dissemination of tumor with spine MR and CSF cytology. Despite radiotherapy and shunt operation, the patient died twelve months after surgery due to tumor progression. This combination is extremely rare and the first observed case of ventricular gliosarcoma arising in the third ventricle. Type I neurofibromatosis is usually associated with benign intracranial tumors, but malignant neoplasms such as gliosarcoma should be considered in patients with NF I. P245. CEREBELLAR GLIOBLASTOMA MULTIFORME OCCURRING AT THE SITE OF A MEDULLOBLASTOMA TREATED 10 YEARS BEFORE R. Martinez1, E. Hofmann2, R. Behr3, O. Basten4, S. Ropero5, M. Esteller6; 1Department of Neurosurgery, University of Goettingen, Germany, 2Department of Neuroradiology, Klinikum Fulda, Germany, 3Department of Neurosurgery, Klinikum Fulda, Germany, 4Institute of Pathology, Klinikum Fulda, Germany, 5Spanish National Cancer Centre, CNIO, Madrid, Spain, 6Spanish National Cancer Centre, Madrid, Spain Objective: The occurrence of a glioblastoma multiforme (GBM) in association with a medulloblastoma is extremely rare. We report such a case 10 years after treatment of cerebellar medulloblastoma. The patient was a 42-year-old female who had undergone gross-total removal of a medulloblastoma and received cranio-spinal radiotherapy at the age of 32. After 1st surgery no tumor relapse occurred during follow-up for 10 years until a new tumor mass was observed at the original site of the medulloblastoma. Methods: Both tumor specimens were assessed by histological, immunohistochemical, and molecular analyses. In order to define a major epigenetic tumor characteristic methylation specific polymerase chain reaction (MSP) was applied for the promoter status of the DNA repair gene MGMT. Bisulfite sequencing was performed to confirm MSP results. Results: Histologically, both tumors were strikingly different. The first tumor was highly cellular and consisted of small cells with scanty cytoplasm and hyperchromatic nuclei. The second tumor consisted of large pleomorphic cells with hyperchromatic nuclei. Multinucleated cells, microvascular proliferation, mitoses, and apoptotic nuclei were observed as well. Immunohistochemical assessment revealed positivity for GFAP but not for synaptophysin. A molecular level, hypermethylation of MGMT promoter was demonstrated in the GBM but not in the medulloblastoma. Conclusions: Although medulloblastoma is capable of differentiation along astrocytic lines, this tumor entity has been rarely observed in association with an astrocytoma. According to Cahan, the reported GBM rather represents a radiation-induced neoplasm since it developed within the primary irradiation field, there was a prolonged latency of 10 years between both tumors, the patient did not suffer from genetic predisposing conditions and consistent molecular and histological differences were patent. The development of a new local intracranial mass should be kept in mind as a possible late sequel of medulloblastoma radiotherapy. P246*. ANTI-ANGIOGENIC COMPOUNDS CAUSE VESSEL NORMALIZATION IN GLIOMAS A. Claes, C. Maass, J. W. Jeuken, W. P. Leenders, P. Wesseling; Dept. of Pathology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands Glioblastomas are characterized by a marked angiogenic reponse. The promising results of angiogenesis inhibitors (AIs) in other cancers have led to the first clinical trials with AIs in GBM patients. Various clinical trials are currently performed in which GBM patients are treated with a combination of chemotherapy (temozolomide [TMZ], irinotecan) and an AI (e.g., bevacizumab, PTK787). However, the results of these studies are disappointing so far. The aim of this research is to test various anti-angiogenic regimens that affect different components of VEGF-A or PDGFR signaling pathways and select the optimal therapeutic regimen for AIs and for combination of AIs with TMZ. For this, we use the genotypically and phenotypically relevant, orthotopic E98 xenograft model which reproducibly shows both a typical diffuse infiltrative growth pattern and an angiogenesis-dependent, more compact growth pattern. Mice carrying intracerebral E98 tumors were treated with four different anti-angiogenic regimens (vandetanib, avastin, sutent, combination of vandetanib and sutent). Vandetanib and avastin affect angiogenesis predominantly via VEGF-A signaling pathways, whereas sutent also affects pericyte coverage and maturation of blood vessels via PDGFR. All regimens caused an obvious anti-angiogenic response. The angiogenesis-dependent component of the E98 tumor showed a strong increase in hypoxia and absence of microvascular proliferations. However, none of the treatments had a notable effect on the diffuse infiltrative components or resulted in prolonged survival. This can be explained by resistance of diffuse glioma parts to AIs due to the incorporation of the pre-existent brain microvascular network. In addition, all compounds induced restoration of the blood-brain barrier (BBB), resulting in reduced visibility in Gd-DTPA enhanced MRI-scans. This latter effect was also found in another orthotopic glioma model (U87) characterized by compact growth. Such AI induced normalization of the brain tumor microvasculature may not only lead to overestimation of the effect of anti-angiogenic therapy in a clinical setting, but may under certain circumstances also hamper the extravasation of chemotherapeutic compounds (e.g., TMZ). Based on these studies, we conclude that the application of anti-angiogenic therapy (whether or not in combination with chemotherapy) for human glioma patients should be performed with caution. P248. AN IMMUNOHISTOCHEMICAL ANALYSIS OF INVASION AND ANGIOGENESIS IN HUMAN MALIGNANT GLIOMA S. Inoue, T. Ichikawa, T. Maruo, H. Kosaka, K. Yoshida, M. Onishi, H. Kambara, I. Date; Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan Introduction: One of the most important hallmarks of malignant gliomas is their invasive behavior. Invasion is a critical prognostic factor for primary brain tumors, yet its pathophysiology is not well understood. Here we evaluated surgical specimen of human glioblastomas to clarify invasive patterns of glioma cells and their relationship with angiogenesis. Materials and Methods: Five patients who suffered from glioblastoma were selected for this study. Lobectomy was performed to remove entire tumor and surrounding brain parenchyma beyond the boundaries of the tumor demonstrated by MRI. Immunohistochemical analysis of these specimen were performed using antibodies against MAP2e; a specific marker for human malignant glioma cells, von Willebrand factor (vWf); a marker for vascular endothelial cells, vascular endothelial growth factor (VEGF) and annexin A2; and angiogenic factors. Results: To analyze the relationship between invasion and angiogenesis, double staining with anti-MAP2e and anti-vWf antibodies was performed. Marked angiogenesis was seen in the core of the tumor and in the normal parenchyma adjacent to the tumor margin. Invading glioma cells were clearly shown by immunohistochemical staining against MAP2e. In the normal parenchyma adjacent to the tumor margin, glioma cells formed clusters around newly developed vessels. Single-cell infiltrations which were independent of vasculature were also seen in this area. Such infiltrations of single cells preceded the cluster formation around new vessels in normal parenchyma distant from tumor core. Immunohistochemical analyses of VEGF and annexin A2 showed predominant expression in the tumor cells around newly developed vessels. Conclusions: The results of this study indicated that malignant glioma cells had at least two patterns of invasion. Glioma cells in the advancing front produced angiogenic factors and promoted vascular formation toward tumor core. These cells coopted newly developed vessels and extended along perivascular spaces. This phenotype of invasion was thought to be angiogenesis-dependent. Other single invading cells did not follow the vasculature and reached distant area where angiogenic event did not take place. This phenotype of invasion was angiogenesis-independent and was rather reliant on high motility. Understanding pathophysiology and molecular mechanisms of glioma invasion may lead us to the development of new treatment modality. P249*. ESCAPE FROM ANTI-ANGIOGENIC THERAPY? PHENOTYPIC CHANGES INDUCED BY ANTI-VEGF TREATMENT S. J. Grau, J. Thorsteinsdottir, F. Winkler, L. von Baumgarten, J. Tonn, R. H. Goldbrunner; Grosshadern University Hospital, Munich, Germany Background: Neoangiogenesis is a critical feature in malignant solid tumors. Thus, anti-angiogenic therapies targeting the VEGF-A/VEGFR-2 system are promising adjuvant treatment modalities. First clinical and preclinical studies demonstrate that therapies using anti-VEGF-A antibodies (e.g., bevacizumab, Avastin) are capable to improve progression free survival in some solid tumors. However, increasing data show that during long term anti-VEGF-A therapy, resistance phenomena resulting in secondary reangiogenesis occur after a transient reduction and normalisation of tumor vascularisation. Thus, alternative signaling molecules are discussed to be involved in escaping anti-VEGF therapies. Methods: Human brain derived endothelial cell lines and CD31 positive endothelial cells freshly isolated from glioblastoma as well as glioma cell lines U87, U373 and U251, were treated with bevacizumab (Avastin) for different time periods. Cell growth and expression of vascular endothelial growth factors VEGF-A, VEGF-C, VEGF-D, and VEGFR-3 were assessed. Additionally, intracellular and functional response of the cells to these factors were investigated. Results: Bevacizumab decreased proliferation by 10% after 12 days of treatment in all cell types. No growth reduction was observed during short time treatment (four days). After long term treatment all cell lines showed a significant up-regulation of VEGF-D protein expression. Even more, cells developed reactivity to VEGF-C and -D by means of increased proliferation while being unreactive to these substances before bevacizumab treatment. VEGFR3 protein expression was not increased significantly, however, phosphorylation of VEGFR3 by VEGF-A, VEGF-C and -D was enhanced in cells treated with bevacizumab. Intracellular response to VEGF, VEGF-C and -D changed in a cell type specific manner with a shift from Erk1/2 to p38 and SAP/JNK phosphorylation. Conclusion: Treatment with anti-VEGF antibodies in glioma leads to a phenotypic change with upregulation of VEGF-D and increased reactivity to VEGF-C and -D accompanied by intracellular changes in signal transduction. This may represent an escape mechanism of the tumor to therapies targeting the VEGF-A/VEGFR-2 system with a secondary activation of the VEGF-C/D-VEGFR3 system. P250. NARCICLASINE DISPLAYS POTENT AND SELECTIVE ANTI-TUMOR EFFECTS BY IMPAIRING GLIOBLASTOMA CELL MIGRATION THROUGH A PHOSPHOCOFILIN-MEDIATED INCREASE OF ACTIN STRESS FIBERS F. Lefranc1, L. Ingrassia2, E. Van Quaquebeke2, F. Darro2, R. Kiss1; 1Free University of Belgium, Brussels, Belgium, 2Unibioscreen, SA, Brussels, Belgium Among the compounds isolated from amaryllidaceae, the isocarbostyrils have long been under scrutiny as promising anti-cancer agents, and notably narciclasine (NCL) and pancratistatin are in the NCI database. However, little is known of the mechanism of action of this family of compounds. NCL was originally described as anti-mitotic and displaying colchicine-like effects. More recently, it has been demonstrated that pancratistatin, whose chemical structure is very close to that of NCL, induces rapid apoptosis in SHSY-5Y neuroblastoma cells. We have recently shown that NCL at 1 μM in vitro induces marked apoptosis-mediated cytotoxicity in certain human cancer cells but not in normal fibroblasts, by triggering the activation of initiator caspases in the death receptor pathway (capase-8 and 10) at least in human MCF-7 breast and PC3 prostate carcinoma cells. In the studies reported here, NCL inhibited cell growth with mean IC50 values of 30 nM for 6 human tumor cell lines (including U373 glioblastoma [GBM]) investigated, 100 nM for 3 distinct human umbilical vascular endothelial cell lines and 7.5μM for 3 distinct normal human fibroblast cell lines. At 0.1 and 1.0 μM, NCL failed to induce cell death and/or apoptosis in human U373 GBM cells, although it inhibited cell growth with an IC50 of 40nM. At concentrations of 10 and 100 nM, NCL markedly impaired the migration of GBM, prostate and breast cancer cells, a feature paralleled by compound-induced loss of tumor cell polarity. NCL also induced rapid increases in F-actin concentrations (principally at the cortical cell location) in U373 and PC3 cells, an effect not observed with normal fibroblasts at the same concentration. Moreover, the increase in F-actin was associated with a dramatic modification in serine/threonine phosphoprotein expression in human U373 GBM cells. Given that altered cofilin expression controlled by phosphorylation is associated with the initiation and progression of conditions involving actin dynamics, such as cancer, the effects of NCL on cofilin phosphorylation status were assessed. NCL treatment significantly and rapidly increased cofilin phosphorylation levels in vitro and through this mediated increases in actin stress fibers responsible for the reduced migration seen in cancer cells. In conclusion, NCL could represent an interesting chemical scaffold to derive novel isocarbostyril derivatives for combating apoptosis-resistant migrating malignant gliomas. P251. ESTABLISHMENT OF NOVEL INVASIVE GLIOMA MODELS IN ANIMAL M. Onishi1, T. Ichikawa1, S. Inoue1, T. Maruo1, H. Kosaka1, K. Yoshida1, K. Kurozumi1, H. Kambara1, E. A. Chiocca2, I. Date1; 1Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama City, Japan, 2Department of Neurosurgery, Ohio State University, Columbus, OH, United States Introduction: Despite recent advances in neurosurgical techniques, radiation therapy, and chemotherapy, malignant glioma still have a poor prognosis. Malignant glioma is a highly invasive tumor, and this characteristics contribute to the failure of therapies. The investigation on invasive behavior is indispensable for the development of new therapeutic strategy. Conventional research has employed animal brain tumor models, in which tumor shows noninvasive mass with well-circumscribed borders that push aside the adjacent normal brain rather than invade into it. Here we have established novel invasive animal glioma models which reflect invasive phenotype of human malignant glioma. Materials and Methods: Two canine glioma cell lines (J3T-1 and J3T-2) were derived from the same parental strain by passaging in the subcutaneous space of SCID mice. Brain tumors were established in athymic rat by stereotactic inoculation of cultured cells into the right basal ganglia. Five weeks after tumor implantation, rats were sacrificed and brain sections were made. These sections were stained with hematoxylin and eosin, and immunostained for rat endothelial cell antigen-1 for histological evaluation. Results: J3T-1 cells formed well-demarcated and highly angiogenic tumor in rat brain. Angiogenic activity was predominant in the core of the tumor and normal brain adjacent to the tumor margin. Clusters of tumor cells were seen around newly developed vessels in adjacent normal brain. No single-cell infiltration was seen in this tumor. J3T-2 cells formed poorly-demarcated tumor with a gradient of tumor cell density from center of the tumor to the normal brain parenchyma. Single cells migrated along neuronal fibers without forming cluster. Minimal angiogenesis was seen at the center of tumor. Conclusions: The results of this study clearly showed different types of invasion in relation to the angiogenesis. We have previously shown that malignant glioma cells had at least two patterns of invasion in human surgical specimen. One is angiogenesis-dependent and the other is angiogenesis-independent. In this study, these models separately reflected two different invasive phenotypes of human malignant glioma. J3T-1 glioma showed angiogenesis-dependent invasion which is limited to perivascular space of newly developed blood vessels. On the other hand, J3T-2 glioma showed angiogenesis-independent and single-cell invasion. These novel invasive glioma models may be new tools for the investigation of glioma invasion and development of a new therapeutic strategy. P252. TEMOZOLOMIDE DISPLAYS ANTI-MIGRATORY EFFECTS IN HUMAN GLIOBLASTOMA CELLS MEDIATED THROUGH NEUREGULIN-1 DOWN-REGULATION F. Lefranc1, S. Spiegl-Kreinecker2, B. Haibe-Kains3, G. Bontempi1, C. Decaestecker1, W. Berger4, R. Kiss1; 1Free University of Belgium, Brussels, Belgium, 2Wagner Jauregg Hospital, Linz, Austria, 3Jules Bordet Institute, Brussels, Belgium, 4Medical University of Vienna, Vienna, Austria Glioblastoma (GBM) patients have a median survival expectancy of only 14 months on the current standard treatment of surgical resection, followed by adjuvant radiotherapy plus temozolomide (TMZ). At TMZ concentrations of 100 μM, cytotoxicity to GBM cells in vitro seems to be exerted through pro-autophagic and late apoptotic processes. However, we do not believe that these effects of TMZ in vitro at 100 μM can explain the significant therapeutic benefits (T/C index of ⩾200%) of relatively low repeat TMZ p.o. or i.v. administration (40 mg/kg) to athymic mice bearing orthotopic xenografts of human GBM cells. The current study has investigated the: (i) impact of TMZ treatment duration on the survival of GBM bearing mice, (ii) survival of 97 GBM patients under different regimens, including surgery + radiotherapy with TMZ treatment performed following relapse or as soon as radiotherapy began, (iii) effects of TMZ on human GBM cell migration and iv) genome-wide effects of TMZ on U373 cells. Our results reveal that the U373 1p19q non-deleted and T98G malignant astrocytic invasive cells as well as several GBM primocultures present a methylated MGMT promoter. No clear-cut cytotoxic effects were achieved with TMZ up to 100 μM in vitro in several GBM cell lines (U87, U373, and T98G) or primocultures including certain with the methylated MGMT promoter, although this concentration provoked a significant decrease in the wound healing process of U373 cells. The therapeutic benefit of TMZ in mouse models of human U373 and T98G GBM was found to correlate directly to the duration of treatment. The therapeutic benefit of TMZ in mouse models of human GBM primocultures was also demonstrated. The sooner TMZ treatment began, the higher the survival rate achieved. Genomic analysis of TMZ-treated U373 cells revealed 30 genes with >2 or <0.5 fold modification in expression compared to untreated cells. Three categories of genes were modified, including clusters involved in morphogenesis and iron ion homeostasis. One of these, neuregulin-1, known to activate the erbB receptor and enhance glioma cell motility, was significantly decreased after TMZ treatment. In conclusion, TMZ, which has already been reported to display pro-apoptotic and pro-autophagic effects in GBM cells in vitro, also displays significant anti-migratory effects which could be partly mediated by a down-regulation of neuregulin-1. These data bring additional understanding how TMZ contributes therapeutic benefits to GBM patients. P253*. GLIOMA-CELL MIGRATION ON MYELINATED AXONS IN VITRO P. Oellers1, V. Senner2, W. Paulus3, S. Thanos1; 1Department of Experimental Ophthalmology, School of Medicine, Münster, Germany, 2Institute of Neuropathology, School of Medicine, University Hospital Münster, Münster, Germany, 3Institute of Neuropathology, School of Medicine, University Hospital Münster, Münster, Germany Malignant gliomas invade diffusely within the healthy brain via existing white-matter tracts, which limits the therapeutic options and hence renders these tumors incurable despite the continuing advances in brain imaging, neurosurgery, and chemotherapy. The interactions between migrating glioma cells and myelinated fiber tracts are poorly understood. We identified that C6 glioma cells can migrate along myelinated chicken retinal axons in a novel coculture. Glioma cells migrated faster in vitro along myelinated axons than on laminin-1. Treatment of the coculture with Rho-kinase inhibitor Y27632 led to diametral cell responses pending on the substrate: C6 cells on myelinated axons virtually abolished cell migration, whereas C6 cells merely contacting laminin-1 enhanced their migration rate. These data suggest that the mechanisms underlying the migration of glioma cells on myelinated axons differ from those underlying the migration on basement membrane molecules such as laminin-1. P255. INHIBITION OF CYCLIN-DEPENDENT KINASES BY ROSCOVITINE INDUCES SUPPRESSION OF PROLIFERATION AND MIGRATION IN HUMAN GLIOMA CELLS A. L. Hoffmann, K. Eckermann, M. Bähr, J. Weishaupt, H. M. Strik; Department of Neurology, Göttingen, Germany Introduction: Cyclin-dependent kinases (CDK) play an important role in numerous cellular processes. CDK1, 2, 3, 4, and 6 are potent regulators of the cell cycle machinery, whereas CDK5 activity is limited to the CNS as a key regulator of neural development and neuronal cytoarchitecture. Galectins are overexpressed in different types of neoplasms and are also involved in various cellular processes, including resistance to apoptosis, proliferation and migration. Roscovitine is an orally available small-molecule inhibitor mainly of CDK5, and with lower activity of CDK-1, -2, -7 and -9. Davanat is a polysaccharide-galactomannan polymer directed against some galectins (i.e., Davanat binds with Galectin-1 [data by Pro-Pharmaceuticals, Inc., Newton, Massachusetts]). We tested here the effect of Roscovitine and Davanat (obtained from Pro-Pharmaceuticals) on migration and proliferation in human glioma cell lines in monotherapy and combination. Methods: Five human glioma cell lines (A172, U87MG, U118, U373, T98G) were treated with 25 or 50 μM Roscovitine, with 1 μg/μl Davanat, and with both compounds in combination. Proliferation was assessed after 48h with cell titer blue reagent. Migration was assessed with a transwell assay. Results: Proliferation and migration was suppressed significantly with Roscovitine in both concentrations. While Davanat alone showed no effect, it enhanced the migration-inhibiting effect of Roscovitine by two- to four-fold in combination. Discussion: We present here evidence that inhibitors of CDKs suppress migration of human glioma cells. Effects on migration in other cell types have been previously described for Roscovitine. Suppressed proliferation has been described only when Roscovitine was combined with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). In view of these observations, CDK inhibition appears to be a promising strategy for the treatment of human malignant gliomas which may be further enhanced by galectin-inhibition. The exact value of additional galectin inhibition and / or conventional chemotherapy has to be assessed in future studies. P256. PROTEOMICS-BASED ANALYSIS OF INVASION-RELATED PROTEINS IN MALIGNANT GLIOMAS T. Maruo1, T. Ichikawa1, H. Kanzaki2, M. Onishi1, S. Inoue1, K. Yoshida1, H. Kambara1, M. Ouchida2, K. Shimizu2, I. Date1; 1Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan, 2Department of Molecular Genetics, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan Introduction: One of the insidious biological features of gliomas is its potential to invade normal brain tissue extensively, yet molecular mechanisms that dictate this locally invasive behavior remain poorly understood. To understand the molecular basis of the invasion in malignant gliomas, we performed proteomic analysis of invasion-related proteins by using invasive glioma cell lines. Methods and Results: We previously established two glioma cell lines (J3T-1 and J3T-2) that show different phenotype of invasion in rat brain; J3T-1 forms well-demarcated and more angiogenic tumor. In contrast, J3T-2 forms tumor with obscure margin by highly invasive tumor cells. These cell lines have similar genetic background because they were established from the same parental strain, so it makes easy to compare molecular fluctuation between them in the experimental settings. For proteomic analysis, whole cell lysate of each cell line was isolated by standard method. Two-dimensional protein electrophoresis (2-DE) was performed using pH3–10 IPG DryStrip (BIO-RAD), followed by SDS-PAGE. The images of SYPRO Ruby-stained gels were analyzed using PDQuest software (BIO-RAD), with spot densities compared at defined coordinate positions. Twenty-four distinct spots were recognized when significant alteration was defined as more than a 1.5-fold change in spot density between gels of J3T-1 and J3T-2. The protein spots were excised manually from the gels, and in-gel digestion was performed. Five proteins that demonstrated increased expression in J3T-1, and 15 proteins that demonstrated increased expression in J3T-2 were identified using LC-MS/MS (Agilent). To confirm differential expression of these proteins, we performed quantitative RT-PCR of cultured cells and immunohistochemical staining of rat invasive brain tumors. Conclusions: Our results revealed significant differences in the proteomic profile between the two cell lines that may correlate with difference of invasiveness. Analysis of these proteins and proteome may enhance understanding of the mechanism of glioma invasion and eventually contribute to the development of new therapeutic modalities. P257. SCREENING OF 100 CNS TUMORS FOR ANTI-INVASIVE THERAPY SENSITIVITY USING AN EX VIVO ASSAY P. C. Costello, J. Megyesi, E. Dyer, W. McDonald, R. Hammond, D. MacDonald; University of Western Ontario, London, ON, Canada Background: Improved treatment for brain tumors is needed. Most models assessing chemotherapies fail to incorporate heterogeneity of patient responses. Tumor progression is dependent on growth and invasion. In this study, 100 surgical samples of primary or metastatic CNS tumors were assessed for invasion and growth parameters while exposed to a panel of clinically relevant chemotherapies. Methods: Surgical tissue specimens were placed into a nutrient-rich collagen matrix and monitored microscopically for 5 days following surgical removal to measure actual distance tumor cells invaded in the presence of several chemotherapies. All samples were preserved for examination of markers related to tumor growth and invasion. Assay data were compared to patient response, time to recurrence and survival up to 3 years. Results and Conclusions: 100 patients' individual tumor therapy sensitivity was assessed. The degree of invasion by tumor cells correlated directly and significantly with degree of malignancy. All 100 tumors displayed a unique and significant (p<0.05) response profile. Results from these data were compared to patient response, time to recurrence, and survival up to 3 years. Individual response to chemotherapy is highly variable both clinically and in our ex vivo assessment. There is however a significant correlation with assay response and post-surgical survival (p<0.05). Pre-screening each patient's responsiveness to therapies could lead to individualized and effective treatment of tumors. P258. ROLE OF METALLOTHIONEIN 1E IN THE MIGRATION AND INVASION OF HUMAN MALIGNANT GLIOMA CELLS S. Jung1, H. H. Ryu2, J. Pei2, S. G. Jin2, T. Y. Jung1, K. S. Moon1, I. Y. Kim1, S. S. Kang1; 1Chonnam National University Hwasun Hospital, Hwasun-eup, hwasun-gun, Republic of Korea, 2Chonnam National University Hwasun Hospital, Brain Tumor Research Lab, Hwasun-eup, hwasun-gun, Republic of Korea Objective: Metallothionein 1E (MT1E) has been found to be highly expressed in motile cell lines. Whether MT1E actually modulates the migration and invasion of human glioma cell lines and what kinds of factors have an effect on MT1E were investigated. Material and Methods: In the human glioma cell lines U343MG-A, U87MG, and U87MG-10`, RNA differential display was evaluated using Genefishing technology; the results were validated by RT-PCR and Northern blot analysis, in order to detect possible genetic changes as the determining factors for motile ability in malignant glioma. MT1E was identified in U87MG, a highly motile cell line. The migration and invasion abilities of human glioma cell line, and MT1E transfectants were investigated using simple scratch testing and matrigel invasion assays. Morphologic and cytoskeletal (actin, vimentin) changes were documented by light and confocal microscopy. The expression of MT1E in four glioma cell lines and astrocytic tumor was assessed by RT-PCR and Western blot. And then the effects of MT1E on the activity of NFkB p50/p65 transcription factor, MMP-2 and -9 were examined in by Western blot and zymography Results: The endogenous MT1E expression in the human glioma cell lines was statistically correlated with their migratory abilities and invasion. The U87-MT-AS cells became more round and decreased stress fibers, compared with the U87MG cells. Endogenous MT1E expressions in the four human glioma cell lines and human astrocytic tumors were directly correlated with their migratory and tumor grade. Two antisense MT1E transfected cell lines showed decreased NFkB p50 translocation into nucleus, which led to decreased the activity of MMP-9 in conditioned media. Conclusion: It may be postulated that MT1E could enhance the migration and invasion of human glioma cells by inducing MMP-9 inactivation via the up-regulation of NFkB p50. P259*. ERUCYLPHOSPHOHOMOCHOLINE-INDUCED CELL DEATH IN HUMAN GLIOMA CELLS: ROLE OF THE 18 KDA TRANSLOCATOR PROTEIN AND THE ANT2 ISOFORM OF THE ADENINE NUCLEOTIDE TRANSPORTER W. Kugler1, P. Hülper1, M. Lakomek1, M. Gavish2, L. Veenman2; 1Universitäts-Kinderklinik, Göttingen, Germany, 2Technion-Israel Institute of Technology, Haifa, Israel Our previous studies indicated that the 18 kDa Translocator protein (TSPO), formerly called peripheral-type benzodiazepine receptor (PBR), may be an important component in the mitochondrial permeability transition pore (MPTP)-related pro-apoptotic mechanisms activated by erucylphosphohomocholine (ErPC3). The use of two well-known TSPO ligands, PK 11195 and Ro5 4864, showed that both ligands interfered with ErPC3's pro-apoptotic activity, i.e., with all stages of the mitochondrial apoptosis cascade. We propose that ErPC3 induces endogenous TSPO activators, while TSPO in turn causes the MPTP to open leading to collapse of the mitochondrial membrane potential, the first stage of the mitochondrial apoptosis cascade. TSPOs are often found in conjunction with the adenine nucleotide transporter (ANT), a suggested core component of the MPTP. ANT appears as a bi-functional protein: an ADP/ATP translocator and a lethal pore regulated by multiple apoptosis modulators. The ANT2 isoform operates to reverse the normal mitochondrial ATP/ADP exchange, importing glycolotic ATP into mitochondria. Here, we studied the effects of ANT2 gene silencing by applying short interfering RNAs. Compared with controls knockdown cells showed a reduced tumor cell proliferation, i.e., reduced DNA synthesis rate over 3 days post-transfection. To determine the effects of TSPO and ANT2 knockdown on ErPC3-induced apoptosis, U87MG cells were transfected with a pool of siRNAs to TSPO and ANT2 and treated with ErPC3 60 h after transfection. Interestingly, we found that silencing both the expression of TSPO and ANT2 resulted in reduced apoptosis induced by a 12 h treatment of ErPC3. Possibly, either ErPC3 prevents ANT2 to fulfill the energy requirements of the mitochondria, or ErPC3 treatment leads to transformation of ANT into the lethal pore mentioned above, as an initiating step for the mitochondrial apoptosis pathway. To study in more detail the mechanisms whereby ErPC3 may affect mitochondrial functions, we analyzed a possible correlation between ErPC3, TSPO, and ANT by investigating cellular ATP levels. ErPC3 reduced cellular ATP levels in U87MG and U118MG cells, while co-administration of ErPC3 with the TSPO ligands, PK 11195 and Ro5 4864, restored cellular ATP levels. Together, these results suggest that TSPO as well as ANT are involved in ErPC3's mechanisms of action. Supported by Joint Lower Saxony-Israeli Research Projects; VWZN2047. P260*. THE INFLUENCE OF RAD51 MEDIATED REPAIR ON TREATMENT RESISTANCE IN HIGH-GRADE GLIOMAS S. C. Short1, C. Martindale1, M. Worku1, S. Bourne2; 1UCL Cancer Institute, London, United Kingdom, 2University of Oxford, Oxford, United Kingdom Purpose: To investigate the influence of Rad51 mediated homologous repair of DNA double strand breaks on radio and chemo-resistance in glioma cell lines Materials and Methods: 4 glioma cell lines were investigated. Western blotting was used to assess Rad51 protein levels before and after irradiation and/or temozolomide (TMZ) treatment in asynchronous and growth arrested cells. Immunohistochemistry was used to assess protein levels in equivalent xenograft tumors. Immunofluorescence was used to investigate changes in Rad51 foci formation after clinical XR doses and/or TMZ exposure. DSB repair kinetics following XR and/or TMZ were studied using phosphorylated H2AX foci counting. The effect of short interfering RNA targeting Rad51 on radiosensitivity and chemosensitivity was assessed in clonogenic survival experiments. Results: All 4 glioma cell lines exhibited high Rad51 protein levels, which did not increase following irradiation or exposure to temozolomide. 3 of these cell lines that could be established as xenografts also demonstrated high Rad51 levels in tumor tissue sections. All 4 cell lines showed a dose dependent increase in Rad51 foci formation after XR, significant increase following clinically relevant TMZ exposure, and a further increase after combination treatment. Rad51 knockdown produced significant radio and chemosensitisation assessed by clonogenic survival and produced a marked effect on reducing cell survival when both agents were used together. Rad51 knockdown also delayed DSB repair assessed by phosphorylated H2AX foci counting after irradiation, temozolomide and most markedly after combination treatment. Conclusions: High Rad51 levels in radioresistant glioma cells are replicated in equivalent xenograft models and are associated with significant Rad51 activation at repair foci on DNA following XR, TMZ, and combination treatment. Targeting Rad51 dependent repair causes significant radio and chemo-sensitisation and suggests that agents that inhibit recombination repair may be useful clinical adjuncts to treatment for high-grade gliomas. Increased residual unrepaired DSB 24h after combination treatment suggests that Rad51 inhibition may significantly improve the outcome of repeated exposure to combination treatment given within 24h. P261. EFFECTS OF TYROSYNE KINASE INHIBITORS IN GLIOMA CELL LINES AND PRIMARY TUMOR CULTURES A. García-Claver, Y. Ruano, E. Pérez-Magán, J. Orradre, G. Guzmán, J. Andrade, M. Mollejo, B. Meléndez, Y. Campos-Martín; Hospital Virgen de la Salud, Toledo, Spain Introduction: The epidermal growth factor receptor (EGFR) is a tyrosine kinase receptor which is usually overexpressed in various epithelial tumors and gliomas. Activation of the EGFR/PI3K/AKT pathway is a common process in the development and progression of the tumors of the central nervous system, making it a compelling target for directed therapy. The use of tyrosine kinase inhibitors (TKIs) either alone or in combination with other inhibitors downstream of the pathway is currently being considered for the treatment of human tumors including malignant glioma. Materials and Methods: Twelve glioma cell lines (U373, U87MG, U118, SW1088, A172, SW1783, H4, GOS3, LN18, LN405, SF767, T98G) and 5 primary cultures from glioblastoma multiforme (GBM) tumors were treated with erlotinib and gefitinib (EGFR inhibitors), LY294002 (PI3K inhibitor), or temsirolimus (mTOR inhibitor), either alone or in combination. Cell viability after 72 hours treatment was measured by MTT assay. Expression of EGFR, PTEN and p53 in these cell lines was studied by immunohistochemistry and Western blot. RT-PCR was carried out in order to identify the mutant EGFRvIII commonly expressed in patients with GBM. Results and Conclusion: Based on the results of the MTT assay, cell lines were classified as sensitive or resistant according to their response to each inhibitor. Combined treatment showed that some monotherapy-resistant cell lines responded to the TKI therapy when using an additional inhibitor downstream of the pathway, such as temsirolimus. In particular, 5 erlotinib-resistant cell lines (U118, A172, SF767, H4, LN405) become sensitive after a combined treatment with temsirolimus. Molecular analyses revealed that EGFR overexpression was observed in all glioma cell lines and that none of them expressed the mutant receptor EGFRvIII. Expression of PTEN and p53 were also analyzed and correlated with response to each treatment. Understanding the molecular mechanisms involved in response to inhibitor therapies using glioma cell line models will help us to predict the possible effectiveness of a given therapy in GBM patients. P262. BRAIN CANCER F98 GLIOMA MODEL TREATED WITH IONIZING RADIATION AND PLATINUM COMPOUNDS: STUDIES ON CYTOTOXICITY, SYNERGISM AND CELL UPTAKE G. Charest, L. Sanche, D. Fortin, B. Paquette; Université de Sherbrooke, Sherbrooke, QC, Canada Background: Free platinum formulation: cisplatin, carboplatin and oxaliplatin as well as their liposomal formulation (Lipoplatin for cisplatin and Lipoxal for oxaliplatin) are largely used as cytotoxic agents in the treatment of many tumor types. However, free platinum formulation are known to cause severe adverse reactions including renal toxicity, gastrointestinal toxicity, peripheral neuropathy, asthenia and ototoxicity. On the other hand, radiotherapy potentially can cause the appearance of new cancers and may enhance invasion of existing cancer. To reduce side effects of these therapies and maintain an efficient antineoplasic effect, one may consider lowering the dose of individual therapeutic treatments and combining both therapies to obtain a synergistic superadditive effect. In treatment against glioblastoma multiform, the development of an aggressive but selective therapy is needed. In this project, we tested different platinum compounds to identify which one shows the best synergy with radiation. Material and Methods: The cytotoxicity of platinum compounds against F98 glioma cell line in-vitro was assessed by colony formation assay. Cell uptake of platinum in this cell line and platinum was measured by Induced coupled plasma mass spectrometer. After four hours exposure to platinum, cells were irradiated (2.21 Gy) with a 60Co source. Results: The relative cytotoxcicity induced by the five platinum formulations was oxaliplatin > Lipoxal > cisplatin > Lipoplatin > carboplatin. On the other hand, when F98 cell line incubated with platinum were irradiated, the combination index calculated and the relative potency were Lipoplatin > carboplatin > oxaliplatin > Lipoxal > cisplatin. Cell uptake of platinum were Lipoplatin > Lipoxal > oxaliplatin > cisplatin > carboplatin. Conclusions: In the present work, Lipoplatin shows the best cytotoxic combination with radiation to treat F98 cell line in vitro and shown the best cellular uptake. These results establish the efficiency of platinum compounds for radio-chemotherapy in vitro to treat F98 provide clues to manage in vivo experiments. They indicate new avenues to improve the treatment of brain cancer and increase the survival rate of GBM patients. P263. BYPASSING THE STEREOTACTIC IMAGING STEP PRIOR TO GAMMA KNIFE RADIOSURGERY FOR RECURRENT EXPERIMENTS IN SMALL ANIMALS G. Charest, D. Mathieu, M. Lepage, D. Fortin, B. Paquette, L. Sanche; Université de Sherbrooke, Sherbrooke, QC, Canada Objective: Accurate targeting is crucial for the irradiation of a small volume in an animal model, such as lesions produced in the rat brain by a Gamma Knife. To assure precise targeting, usually X-ray imaging or magnetic resonance imaging (MRI) step was done before each radiosurgery planning. To avoid this step, prior recurrent experiments of radiosurgery in rats, we build an enhanced new type of stereotactic frame that allow exact repositioning of animal scull. We propose an original method based on a polymer gel dosimeter to determine the accuracy and reproducibility of irradiation using this new stereotactic frame. Methods: An in-house designed rat stereotactic frame compatible with the Gamma Knife Automatic Positioning System was constructed. Initial spatial coordinates to target the right frontal lobe were acquired by X-ray imaging of the rats positioned in the stereotactic frame using the Gamma Knife angiographic fiducial box. The rat brain was then removed through a small burr hole and the intracranial cavity was washed and filled with the polymer gel dosimeter. This “gel brain” was irradiated at a dose of 15 Gy using 4 or 8 mm collimator helmets. The irradiated volumes coordinates were measured non-invasively by MRI or visually after excision of the polymer gel. The position of the polymerized areas revealed that the stereotactic frame is able to accurately reproduce the same position of irradiation in each animal. The average location of the center of the polymerized areas was as follows: X = 3.07 ± 0.31 mm, Y = 5.50 ± 0.26 mm, and Z = 0.90 ± 0.45 mm when using 8 mm collimators; and X = 2.86 ± 0.18 mm, Y = 6.00 ± 0.22 mm, and Z = 0.58 ± 0.39 mm for 4 mm collimators. The small standard deviation demonstrated that assessment of the irradiated volume performed with the gel dosimeter was highly reproducible. Conclusion. The polymer gel dosimeter confirmed the ability of the rat stereotactic frame to accurately and reproducibly position a small animal for precise radiosurgery procedures. Protocol for irradiating implanted glioblastoma in rat brain using Gamma Knife can then be executed repeatedly without the need of stereotactic imaging before irradiation. P264. CYCLOPHOSPHAMIDE ENHANCES HUMAN TUMOR GROWTH IN NUDE RAT XENOGRAFTED TUMOR MODELS E. A. Neuwelt, Y. Wu, D. Dickey, S. Lewin, C. Varallyay, L. L. Muldoon; Oregon Health and Science University, Portland, OR, United States Background: We investigated pretreatment with the immuno-modulatory chemotherapeutic agent cyclophosphamide as a mechanism to improve tumor growth in primary and metastatic intracerebral and subcutaneous nude rat xenograft models. Methods: Nude rats were treated with cyclophosphamide (100 mg/kg IP) 24 h before inoculation of human ovarian carcinoma (SKOV3), lung carcinoma (LX-1), and glioma (UW28, U87MG and U251) cells. Tumor cells were inoculated subcutaneously (2.5 × 107 cells mixed with matrigel) or 106 cells were injected in the right cerebral hemisphere or infused into the right internal carotid artery. Intracerebral tumor growth was monitored by magnetic resonance imaging and histology. Results: Only animals that received both cyclophosphamide and matrigel showed consistent growth of subcutaneous lung and ovarian carcinoma tumors. In intracerebral implantation tumor models, cyclophosphamide pretreatment increased tumor volume and the percentage of animals showing tumors. Cyclophosphamide increased lung carcinoma bone and facial metastases after intra-arterial injection, and 20% of animals showed brain metastases. Cyclophosphamide transiently decreased nude rat white blood cell counts and glutathione concentration, while serum vascular endothelial growth factor (VEGF) was significantly elevated 7 days after cyclophosphamide administration. Cyclophosphamide also increased CD31-positive cell populations and macrophage (CD68-positive) infiltration into glioma cell-inoculated rat brains. Conclusions: Decreased serum glutathione, elevated serum VEGF level and infiltration of brain by CD31-positive and CD68-positive cells after cyclophosphamide may modulate inflammation and angiogenesis, resulting in enhanced primary and metastatic tumor growth. These findings may be clinically relevant, because chemotherapy may predispose human cancer subjects to tumor growth in the brain or other tissues. P265. SC68896, A NOVEL PROTEASOME INHIBITOR, DELAYS GROWTH OF MALIGNANT GLIOMA CELLS IN VITRO AND IN VIVO P. Roth1, F. Schmidt2, C. Herrmann2, M. Kissel3, J. Leban3, M. Weller1; 1Department of Neurology, Zurich, Switzerland, 2Department of Neurology, Tuebingen, Germany, 34SC AG, Planegg-Martinsried, Germany Despite multimodal therapy, the prognosis of patients with malignant gliomas remains poor. Inhibition of the proteasome of glioma cells may provide a promising therapeutic strategy. Here, we describe the in vitro and in vivo effects of SC68896, a novel substance that has been developed as an inhibitor of the proteasome. Application of SC68896 to cancer cells of different origins, including gliomas, inhibited their proliferation in vitro. Only nanomolar concentrations were necessary to reduce the enzymatic activity of the proteasome by more than 90%. Administration of SC68896 efficiently sensitized glioma cells for TRAIL- or FasL-induced apoptosis. SC68896 did not affect the expression of p53 and p27, while p21 levels were markedly increased. Using an orthotopic glioma nude mouse model, we observed an increased survival of mice treated with SC68896 compared with the control-treated mice. These data demonstrate that SC68896 has in vitro and in vivo activity against malignant glioma cells and may therefore be of interest for therapeutic studies in glioma patients. P266. TRANS-MEMBRANE-P53 PEPTIDE THERAPY FOR GLIOMAS H. Kanno1, N. Kobayashi2, T. Yoshida3; 1School of Medicine, Yokohama, Japan, 2Institute for Advanced Sciences, Toagosei, Ltd., Tsukuba, Japan, 3Institute for Advanced Sciences, Toagosei, Ltd., and Keio University, Tsukuba, Japan Recent studies suggest that several proteins can transverse biological membranes through protein transduction. The protein transduction domains of these proteins, 10–16 residues long, have been identified as critical domains for the protein transduction. Poly-arginine peptide also has the ability of protein transduction. Here, we show that the protein delivery system using 11 poly-arginine peptides (11R) is a powerful tool for the transduction of the biologically active tumor suppressor protein, p53, to suppress the proliferation of oral cancer cells. Nine amino-acid sequence corresponding to MDM2 binding site shows proliferation inhibitory effect for cancer cells. The 11R-nuclear localization sequence (NLS) fused p53 peptide corresponding to MDM2 binding site (11R-NLS-p53) effectively penetrated across the plasma membrane of the glioma cells and translocated into the nucleus. From 10μM in concentration, the peptides inhibited the proliferation of human glioma cells, in which the p53 gene was mutated. Moreover, 11R-p53 enhanced the chemotherapeutic agent-dependent induction of apoptosis of the cells. These data suggest that this protein transduction method may become a promising glioma therapy as an alternative gene therapy. P267. UNBS5162, A NOVEL NON-HEMATOTOXIC NAPHTHALIMIDE DERIVATIVE THAT INDUCES AUTOPHAGIC AND SENESCENCE PROCESSES IN GLIOBLASTOMA CELLS AND DECREASES THE EXPRESSION OF PROTEINS INVOLVED IN CHEMORESISTANCE F. Lefranc1, T. Mijatovic2, N. De Neve2, J. Gaussin2, E. Van Quaquebeke2, F. Van Vynckt2, F. Darro2, R. Kiss1; 1Free University of Belgium, Brussels, Belgium, 2Unibioscreen, SA, Brussels, Belgium Glioblastomas (GBM) are characterized by diffusely infiltrating malignant glioma cells that are resistant to apoptosis. Although cell death can be achieved not only by apoptosis (type I programmed cell death) but also by necrosis, autophagy (type II programmed cell death), mitotic catastrophe and senescence, drugs inducing apoptosis remain the main chemotherapeutic agents in medical oncology. Amonafide, a naphthalimide which binds to DNA by intercalation and poisons topoisomerase II, has demonstrated activity in phase II cancer trials, but has failed thus far to enter clinical phase III because of dose-limiting bone marrow toxicity which is linked to its metabolism to a toxic metabolite, N-acetyl-amonafide. The present study aims to report the effects of a novel non-hematotoxic naphthalimide on human GBM cells. We originally designed a novel anti-cancer naphthalimide with a distinct mechanism of action; the compound UNBS3157 (2,2,2-trichloro-N-({2-[2-(dimethylamino)ethyl]-1,3-dioxo-2,3-dihydro-1H-benzo[de]isoquinolin-5-yl}carbamoyl) acetamide is obtained in three chemical steps from commercially available 3-nitro-1,8-naphthalic anhydride. UNBS3157 presents in vitro anti-proliferative activity (IC50 range of 0.8–1.8μM) against human cancer cell lines, including GBM (Hs683 and U373-MG), similar to that of amonafide (IC50 range of 2.7–5.8 μM). This compound which has a 3–4-fold higher maximum tolerated dose compared to amonafide and does not provoke hematotoxicity in mice at doses which result in significant anti-tumor effects, is readily hydrolyzed into the compound UNBS5162. Preliminary data indicate that UNBS5162 at 10μM induces autophagic and senescence processes (cell proliferation arrest associated with a significant increase in the percentage of cells in the G2/M phase of the cell cycle) in human Hs683 and U373-MG GBM cells after 72h. Additionally, there is an increase in intra-cellular acidic compartments after 72h, associated with an increase in intra-cellular cathepsin B without modification of Hsp70 levels. Moreover, UNBS5162 significantly decreases the expression of several proteins involved in drug resistance: glucosylceramide synthase and Rho guanine nucleotide dissociation inhibitor. UNBS5162 also increases the therapeutic benefits of temozolomide in immuno-compromised mice bearing orthotopic xenografts of human U373 GBM cells. P268*. TARGETED DELIVERY TO PRIMARY BRAIN TUMORS USING LIPOSOMES M. Bellavance, F. Gobeil, D. Fortin; Sherbrooke University, Sherbrooke, QC, Canada Introduction: Systemic treatment of many CNS diseases, such as brain tumors, is considerably impaired by limited delivery of therapeutics by an intrinsic obstacle, the blood-brain barrier (BBB). Moreover, highly active efflux pumps can expel therapeutic molecules from the parenchyma back in the bloodstream. We therefore undertook the design of a liposome formulation to deliver increased concentrations of therapeutic agents across the BBB, to primary brain tumors. Material and Methods: Briefly, a lipid mixture (DSPC, cholesterol and DSPE-PEG2000-carboxyfluorescein 65:30:5 molar ratio) was dissolved in chloroform and subsequent removal of the solvent was accomplished by rotary evaporation at 65°C during 1 h. Dried lipids were hydrated with an aqueous solution containing 0.03 mg/mL of propidium iodide (PI) and shaken at 65°C during 1 h. Resulting liposomes were freeze-thawed 5 times and extruded 10 times through 2 stacked polycarbonate membranes with pores of 100 nm. The separation of non-entrapped PI was performed by chromatography with pre-packed columns of Sephadex G-25M. The final liposome suspension was stored in glass vials at 4°C. Liposome size and morphological analysis were carried with transmission electron microscopy. For in vitro delivery studies, 106 F98 cells were incubated in complete medium with liposomes or free PI (0.03 mg/ml) at 37°C for 2, 4, 6, 8 and 10 h and cells samples were prepared for FACS analysis. Epifluorescence and confocal microscopy were also employed to monitor the localization of fluorescent markers in transfected cells. Results: The mean size of liposomes was 111±29 nm. FACS analysis results showed that liposomes were taken up by 76% of F98 cells after 2 h and a maximum of 93% was obtained after 10 h. In contrast, free PI stained only 7% of F98 cells at 10 h. Epifluorescence and confocal microscopy studies suggest endocytosis as the delivery mechanism as both liposomal fluorescent markers (membrane-bound and inner markers) co-localize in the cytosol. Conclusion: These promising results show that high lipofection levels of F98 can be obtained with this liposome formulation in vitro. In vitro delivery studies to murine and human cell lines, as well as real-time delivery studies (confocal) and in vivo experiments are underway to determine if the liposomes are successful to circumvent the BBB and deliver their contents to primary brain tumors. P269. CONVECTION ENHANCED DELIVERY (CED) OF IL-4 PSEUDOMONAS EXOTOXIN (PRX321): INCREASED DISTRIBUTION AND MR MONITORING Y. Mardor1, D. Last1, N. Merchant2, S. Denmeade2, D. Daniels1, Z. Ram3; 1Sheba Medical Center, Ramat-Gan, Israel, 2Protox Therapeutics Inc., Vancouver, BC, Canada, 3Tel-Aviv Medical Center, Tel-Aviv, Israel Introduction: Therapeutic efficacy with brain tumors is limited by the poor penetration of drugs across the blood brain barrier. Regional drug delivery using convection, established by creating an infusion-mediated pressure gradient through intracranial catheters, achieves drug concentrations within the brain tumor that are orders of magnitude higher than those achievable by systemic administration. While multi-center clinical trials using convection have been performed, creating efficient convection, monitoring its extent/effect and assessing brain toxicity remain a challenge. Previous phase I and phase IIa trials using intratumoral PRX321 (IL4-PE) have demonstrated an acceptable safety/toxicity profile in patients with recurrent glioblastoma multiforme and anaplastic astrocytoma with promising signs of therapeutic activity. In this study, we used MR imaging to evaluate whether increased infusate viscosity would enhance the efficiency of convection of PRX321 in a normal rat brain model. We studied drug distribution and toxicity of intracranial PRX321 at concentrations used in previous clinical trials, and optimized the formulation in preparation for an upcoming phase IIb trial. Methods: Low viscosity (0.02% HSA, previously used clinically) infusates and high viscosity (3% HSA) infusates mixed with Gd-DTPA (1:70) and PRX321 (1.5mcg/ml) were compared to low/high viscosity infusates without the drug. 40 mcl of each infusate were convected in 8 rats (n=32, total) at 1mcl/min. T1/T2 MRIs were acquired immediately post treatment for assessment of drug distribution and infusion-related toxicity. T1/T2/diffusion-weighted MRIs were acquired 24 hrs and 2 weeks post treatment for assessment of early and late toxicity. Results: The average distribution of 0.02% HSA was larger than that of 0.02% HSA with PRX321 by a factor of 1.98 (p<0.02). The volume of 3.0% HSA with or without PRX321 was larger than that of 0.02% HSA with PRX321 by a factor of 2.93 (p<0.015), suggesting that high viscosity increases CED efficiency of PRX321 by nearly a factor of 3, resulting in similar distribution to that of a high viscosity placebo. No evidence of drug-related toxicity was detected. Conclusions: These results suggest that the low viscosity PRX321 infusate used in previous clinical trials may have convected poorly, and demonstrate that increased viscosity significantly augments CED efficiency by nearly a factor of 3 with no detectable toxicity. On the basis of these results, a high viscosity formulation will be used in the protocol of an upcoming phase IIb PRX321 CED clinical trial. P270. ROLE OF ERCC1 PROMOTER HYPERMETHYLATION IN DRUG RESISTANCE TO CISPLATIN IN HUMAN GLIOMAS H. Chen1, A. Kwan2, Z. Chen1; 1Sun Yat-sen University, Guangzhou, China, 2Kaohsiung Medical University, Kaohsiung, China Background: Overexpression of ERCC1 mRNA and/or protein is associated with drug resistance to cisplatin in human gliomas, but role of ERCC1 promoter in drug resistance has not been demonstrated yet. Methods: In order to determine whether DNA methylation can inhibit ERCC1 expression in human gliomas, we have used sodium bisulfite sequencing to compare ERCC1 promoter methylation patterns in cisplatin-sensitive and cisplatin-resistant glioma cells. Cisplatin cytotoxicity in glioma cells was tested after 5-aza-2′-deoxycytidine or trichostatin A treatment. The levels of ERCC1 DNA methylation, mRNA and protein in 32 human glioma samples were examined by methylation specific PCR, real-time RT-PCR and immunohistochemistry, respectively. Meanwhile cisplatin sensitivities to these human glioma samples were tested by histoculture drug response assay. Results: Hypermethylation was observed in the upstream 5Kb region of the ERCC1 promoter of cisplatin-sensitive glioma cell lines. ERCC1 expression has been enhanced through 5-aza-2′-deoxycytidine or trichostatin A treatment in cisplatin-sensitive glioma cell lines but not in cisplatin-resistance cell lines. ERCC1 DNA methylation levels were highly variable in 32 human glioma samples ranging from 0.1 to 0.87 (95% confidence interval [CI] =0.39 to 0.51), which have showed significant difference between cisplatin-sensitive samples and cisplatin-resistant samples (P<0.05). The relative expression levels of ERCC1 mRNA in 32 glioma samples were also variable from 0.01 to 5.71 (95% confidence interval [CI] =1.46 to 2.46). While no detectable or low expression of ERCC1 protein was showed in 7 glioma samples. ERCC1 promoter methylation was inversely correlated to mRNA expression (r=–0.903 P=0.001) as well as protein expression (r=–0.884 P=0.001). Moreover, ERCC1 mRNA expression was significantly associated with ERCC1 protein levels (r= 0.840 P=0.001). Conclusions: The aberrant CpG island methylation in ERCC1 promoter region exists in human glioma cell lines as well as clinical glioma samples. ERCC1 DNA methylation could regulate the expression of downstream mRNA and protein, and was associated with cisplatin chemosensitivity. P271. ABERRANT PROMOTER HYPERMETHYLATION PROFILE OF CELL CYCLE REGULATORY GENES IN MALIGNANT ASTROCYTOMAS T. Ohta, K. Yachi, A. Ogino, T. Fukushima, T. Watanabe, A. Yoshino, Y. Katayama; Department of Neurological Surgery, Nihon University School of Medicine, Tokyo, Japan Purpose: Aberrant hypermethylation of CpG islands in the promoter region plays a casual role in the inactivation of various key genes involved cell cycle regulatory cascade, which could result in loss of cell cycle control. The aim of the present study was to investigate the role of promoter methylation of genes with a proven role of the cell cycle regulation in malignant astrocytomas. Experimental Design: We profiled the CpG island methylation status of RB1, p14ARF, p15INK4b, p16INK4a, p21Waf1/Cip1, p27Kip1, and p73 genes by methylation-specific polymerase chain reaction assay in a homogeneous cohort of patients with malignant astrocytomas, and assessed their relationships with clinical behavior. Results: Promoter hypermethylation of the RB1, p14ARF, p15INK4b, p16INK4a, p21Waf1/Cip1, p27Kip1, and p73 genes was detected in 3 (5.6%), 7 (13.0%), 4 (7.4%), 2 (3.7%), 1 (1.9%), 3 (5.6%), and 12 samples (22.2%) of the 54 newly diagnosed malignant astrocytomas, respectively. A total of 50% of the cases carried methylation of at least one gene, and only 9.3% of the cases displayed concordant hypermethylation of two genes. None of the tumors disclosed three or more methylated loci. The presence of methylation of these genes or a group of genes was not associated with any distinct clinicopathological characteristics including tumor grade, proliferation activity, responsiveness to adjuvant therapy, and patient survival. p73 protein accumulation examined by immunohistochemical staining was found in 6 (15%) of the 40 samples examined, with no significant association with the methylation status of p73 and any of the clinicopathological parameters tested. Conclusions: Aberrant hypermethylation of the key cell cycle regulatory genes occurs at a relatively high frequency in malignant astrocytomas, independent of each other methylation and clinicopathological parameters. This epigenetic change may be an important early event during the pathogenesis of malignant astrocytomas. P272*. AUTOCRINE AND PARACRINE CONTRIBUTIONS OF FGF5 TO THE MALIGNANT PROGRESSION OF HUMAN ASTROCYTIC BRAIN TUMORS S. Allerstorfer1, C. Pirker1, S. Spiegl-Kreinecker2, J. Pichler3, J. Buchroithner2, M. Grusch1, R. Silye4, J. Fischer2, M. Micksche1, W. Berger1; 1Clinics of Medicine I, Medical University, Vienna, Austria, 2Department of Neurosurgery, Wagner-Jauregg Hospital, Linz, Austria, 3Department of Internal Medicine, Wagner-Jauregg Hospital, Linz, Austria, 4Department of Pathology, Wagner-Jauregg Hospital, Linz, Austria Human fibroblast growth factors (FGFs) are a family of small signal polypeptides (N=22) activating respective transmembrane tyrosine kinase receptors (FGFRs). FGF/FGFR-mediated signals include target cell survival and proliferation. Consequently, deregulation may result in uncontrolled and thus neoplastic cell growth. Aim of this study was to screen for FGF/FGFR expression in human glioma primary cell cultures/tissues and to investigate whether FGF/FGFR-mediated signals might play an important role in the progression of human gliomas. Initial screening demonstrated almost general overexpression of FGF5 mRNA in cell lines (N=51) and tissue samples (N=26) derived from primary gliomas as compared to normal tissues (N=8). Quantitative real-time PCR analyses of in vitro cell cultures and tumors as well as immunostaining of glioma sections confirmed a significant increase of FGF5 mRNA levels with malignant progression of astrocytic brain tumors. FGF5 mainly activates the FGFR1 splice variant IIIc. Consequently, we blocked FGF5/FGFR1 signals at the ligand level by FGF5 siRNA and at the receptor level by a dominant-negative FGFR1IIIc-GFP molecule. While the siRNA approach led to a significantly reduced cell proliferation and hypersensitivity to serum starvation, the dominant-negative FGFR1 additionally activated programmed cell death in several glioblastoma cell lines. Moreover, glioblastoma cell-derived FGF5 exerted paracrine, neoangiogenic effects by promoting endothelial cell (HUVEC) proliferation, migration and tube formation. Moreover, stable overexpression of FGF5 in U373 human glioblastoma cells led to a distinctly more aggressive and invasive tumor cell growth in SCID mice. Summarizing, these data suggest that FGF5 promotes malignant progression of human astrocytic brain tumors by autocrine and paracrine signals. Thus FGF5 and the respective FGFR might represent feasible new therapeutic targets for human glioblastoma multiforme. P273. EXPRESSION OF SYNAPTIC VESICLE PROTEIN 2A (SV2A), THE BINDING SITE FOR LEVETIRACETAM, IN EPILEPSY-ASSOCIATED BRAIN TUMORS AND IN THE PERILESIONAL EPILEPTIC CORTEX S. T. Toering1, K. Boer2, J. J. Heimans1, E. Aronica2, J. C. Reijneveld1,2; 1VU University Medical Centre, Amsterdam, The Netherlands, 2Academic Medical Centre, Amsterdam, The Netherlands Synaptic vesicle protein 2A (SV2A), a membrane glycoprotein present in synaptic vesicles of neurons and endocrine cells, has been identified as the binding site for the anti-epileptic drug levetiracetam. In the present study we compared the expression and cellular distribution of SV2A in surgical specimens of patients with glial (30 glioblastoma multiforme, 5 grade III astrocytoma, 8 grade III oligodendroglioma, 2 grade II astrocytoma, 4 grade II oligodendroglioma, 1 grade II oligoastrocytoma) and glioneuronal (6 ganglioglioma, GG; 6 dysembryoplastic neuroepithelial tumors, DNT) brain tumors with or without epilepsy, with perilesional cortex from patients without an underlying tumor with or without epilepsy. The peritumoral tissue is of particular interest for its contribution to the generation, maintenance and propagation of seizure activity in epilepsy-associated tumors. Immunohistochemical analysis in control neocortical tissue specimens demonstrated strong and diffuse SV2A immunoreactivity of the neuropil, with punctuate labeling over the soma and dendrites of neurons throughout all cortical layers. SV2A was co-localized with the presynaptic marker synaptophysin. Similar distribution of SV2A staining was observed in the peritumoral cortical specimens from patients with or without epilepsy. Modest SV2A immunoreactivity was observed within the tumor area, particularly within glial tumors. There was little evidence of SV2A expression in astroglial and oligodendroglial tumor cells. Glioneuronal tumors displayed variable SV2A neuropil staining. In GG strong SV2A immunoreactivity was present along the dysplastic neuronal cell borders and processes (perisomatic synapses). In both GG and DNT SV2A immunoreactivity was occasionally observed within the neuronal perikarya. The pattern of SV2A immunoreactivity in the peritumoral regions of glial tumor patients with chronic epilepsy suggests that treatment with levetiracetam could be effective in case of epilepsy refractory to traditional AEDs. The distinct pattern of SV2A immunoreactivity in glioneural tumors suggests a redistribution of the SV2A protein. How this may affect the epileptogenicity and/or the effectiveness of levetiracetam needs to be further investigated. P274. COMPLETE SEPARATION AND PHENOTYPING OF THE TUMOR-HOST CELLULAR COMPARTMENTS IN TUMOR BEARING NOD/SCID MICE S. P. Niclou1, C. Danzeisen1, N. H. C. Brons1, H. P. Eikesdal2, P. O. Enger2, R. Bjerkvig1,2; 1CRP-Santé, Luxembourg, Luxembourg, 2University of Bergen, Bergen, Norway Brain tumor research is highly dependent on successful animal models to address tumor initiation and progression in vivo. Immunodeficient rodents such as nude, Rag-1, or NOD/Scid mutant mice are routinely used for implantation of human tumor cell lines and patient biopsies to study tumorigenicity, tumor take and metastasis. In particular the use of fresh patient biopsy material allows a close replication of the human tumor phenotype, however, until recently these models did not allow a straightforward distinction between tumor and host cells. We have generated a green fluorescent protein (GFP)-expressing mouse on the NOD/Scid mutant background by crossing NOD/Scid mice with a transgenic GFP-expressing line. We have characterized this novel mouse line and evaluated its potential for cancer research. GFP-NOD/Scid mice express GFP in all cells except hair cells and erythrocytes. Similar to the parental NOD/Scid line, GFP-NOD/Scid mice lack T and B lymphocytes and have strongly reduced natural killer cell activity in blood and spleen. GFP-NOD/Scid mice accept allogeneic and xenogeneic transplants and develop tumors when injected subcutaneously with different cancer cell lines (brain, breast, colorectal). Highly invasive brain tumor phenotypes can be closely recapitulated using biopsy material from glioblastoma multiforme grown as spheroids and implanted in the brain of GFP mice. The use of red fluorescent protein (RFP)-expressing cell lines allows a clear distinction between red tumor mass and green host cells. Using fluorescence activated cell sorting (FACS) red tumor cells can be separated from invading host cells and will allow us to characterize the tumor microenvironment at the molecular level. Thus, these mice constitute an ideal model to study tumor-host interactions, tumor cell invasion, metastasis and vascular mimicry. The possibility to identify individual green host cells within the tumor, will further allow us to follow the fate of isolated cells (e.g., stem cells) in the tumor and to investigate the occurrence of cell fusion phenomena. P275. THE INGREDIENTS OF ANTINEOPLASTON AS2-1 DOWN-REGULATE GLYCOLYSIS PATHWAYS IN GLIOBLASTOMA CELLS S. Patil1, S. Burzynski1, S. Chittur2, E. Mrowczynski1, K. Grela1; 1Burzynski Research Institute, Houston, TX, United States, 2Center for Functional Genomics, University of Albany, NY, United States Antineoplastons are peptides, amino acid derivatives, and carboxylic acids that inhibit the growth of neoplastic cells without growth inhibitory effect in normal cells. In 2004, the FDA granted orphan drug designation for antineoplastons A10 and AS2-1 for the treatment of brainstem glioma. Twelve FDA-supervised phase II clinical trials have confirmed anti-tumor efficacy in several types of brain tumors. The formulation of antineoplaston AS2-1 is a 4:1 mixture of synthetic phenylacetate (PN) and phenylacetylglutaminate (PG). We have found a dose dependant antiproliferative effect on U87 cells by PG and PN used seperately and in a fixed ratio combination. This report describes one of the studies on the molecular mechanism of action of PG and PN. The human U87 glioblastoma cell line was used as the model system in this study. A total human gene array screen using the Affymetrix Human Genome plus 2.0 oligonucleotide arrays was performed using mRNA derived from U87 cells exposed to PG and PN. The expression of mRNA for vitamin D3 up-regulated protein 1 (VDUP1) was found to be over 100 fold higher in cells treated with PG and PN. This up-regulation was confirmed by quantitative PCR. VDUP1 has been shown to mediate the nuclear export of hypoxia inducible factor 1 alpha (HIF1 alpha) leading to its destabilization. HIFs are transcription factors that activate glycolysis and angiogenesis under hypoxic conditions usually found in tumors. The substantial up-regulation of VDUP1 may play a critical role in the blockade of tumor glycolysis by destabilizing HIF1alpha. Pathway analysis was performed to allow the visualization of the effect on metabolic pathways and gene interaction networks. We found significant down-regulation of genes involved in glycolysis in U87 cells treated with PG and PN. These include succinate dehydrogenase C (SDHC), fumarate hydrogenase (FH), succinate-CoA ligase 1 and 2 (SUCLG1 and 2), and aconitase 2 (ACO2). Malignant brain tumor cells are known to have an abnormally high rate of glycolysis. Therefore targeting these energy metabolism pathways may be considered one of the mechanisms by which antineoplastons inhibit tumor growth. P276. CHEMICAL SYNTHESIS OF GLYCOLIPID DERIVATIVES WITH HIGH INHIBITORY ACTIVITY OF GLIOMA TUMOR GROWTH: IN-VITRO AND IN-VIVO APPROACHES B. Valle-Argos1, D. Gómez-Nicola1,2, M. Nieto-Sampedro1,2; 1CSIC (Cajal Institute), Madrid, Spain, 2National Hospital of Paraplejics, Toledo, Spain In spite of their low incidence, tumors of the central nervous system are responsible for about 2.3% of total cancer deaths, these tumors have an elevated morbidity and mortality. The ganglioside 9-O-Ac-GD1b or neurostatin, present in the mammalian brain, is a potent inhibitor of the division of astroblasts and astrocytoma cells, appearing as a possible candidate for treatment of nervous system tumors. Because the purification of neurostatin from brain is highly laborious, we designed its preparation by chemical O-acetylation of GD1b. Searching for a more stable compound with higher inhibitory activity of tumor cell growth, we also tested O-butyrylation of GD1b. The semi-synthetic compounds efficiently inhibited the in-vitro division of rat and human glioma cells (C6 and U373 cell lines), with ID50 values for neurostatin of 2 μM and 0.2 μM respectively, and ID50 values for 9-O-But Gd1b of 0.8 μM and 0.3 μM respectively. These results have been corroborated by xenotransplants of both rat and human glioma cells (C6 and U373) in nude mice Foxn1nu, obtaining a significant decrease of tumor growth with the administration of low doses of semi-synthetic gangliosides (40 μg/Kg), for both C6 and U373 glioma. Similar results were observed with alotransplants of C6 cells in striatum of Sprague-Dawley rats; low intratumoral doses of semi-synthetic gangliosides (3 μg/kg) decreased the tumoral growth directly reducing tumor size, but also by an indirect effect, leading the recruitment and activation of immune cells (T cells and macrophages). The present results indicate that semi-synthetic O-acetylated and O-butyrylated gangliosides are potent antitumoral compounds that should be considered in strategies of brain tumor treatment. P277. EGF RECEPTOR HETEROGENEITY DRIVES GLIOMA DEVELOPMENT M. Inda1, R. Bonavia1, P. Tan2, P. Hadwiger2, A. Mukasa3,1, Y. Narita4,1, D. W. Y. Sah5, F. B. Furnari1, W. K. Cavenee1; 1Ludwig Institute for Cancer Research-Univeristy of California, San Diego, La Jolla, CA, United States, 2Alnylam Pharmaceuticals, Kulmbach, Germany, 3Department of Neurosurgery, University of Tokyo, Tokyo, Japan, 4Saitama Medical School, Saitama, Japan, 5Alnylam Pharmaceuticals, Cambridge, MA, United States Glioblastoma is typified by a heterogeneous composition of diverse cytological subtypes carrying a variety of gene alterations. An example of heterogeneity that is present in >50% of cases is amplification of the epidermal growth factor receptor (EGFR) gene. This amplification is often accompanied by structural alterations leading to expression of a variant form of the gene, deltaEGFR (also referred to as EGFRvIII, EGFR-de2-7 and EGFR*), which conveys enhanced tumor aggressiveness. This potent tumor-promoting function of deltaEGFR would suggest that it should be the predominant amplified receptor in clinical samples, however, paradoxically, deltaEGFR is usually present as minor and focal populations within tumors having more homogeneous wtEGFR amplification. This disconnect between tumorigenic potential and the frequencies and proportions of the amplified mutant EGFR and wtEGFR in GBM might arise if mutant EGFR occurs later in tumor progression where it not only enhances the tumorigenicity of cells which express it, but also potentiates, the proliferation of neighboring cells expressing amplified wtEGFR. If this were so, the potentiation loop might provide an attractive and novel therapeutic target. Here we report that in vitro treatment of cells expressing wtEGFR with conditioned media from cells overexpressing deltaEGFR resulted in activation of STAT3, Akt, Erk1/2 and wtEGFR. We also observed that an in vivo tumor growth potentiation when wtEGFR overexpressing cells were mixed with deltaEGFR expressing cells, but not when those cells were mixed with cells with normal levels of wtEGFR or overexpressing a dead kinase version of deltaEGFR. Based on these observations, we employed siRNA technology to knock-down either wt or deltaEGFR to assess the effect of specific receptor ablation on tumorigenicity and contribution to heterogeneity. siRNAs specific for deltaEGFR or wtEGFR were able to reduce tumor growth after subcutaneous injection of ex vivo transfected cells. This suggests that specific targeting of signaling molecules as well as the signal between them might enhance the therapeutic potential of targeted inhibitors in heterogeneous cancers. P278*. CIRCULATING ADULT HUMAN MESENCHYMAL STEM CELLS CONTRIBUTE TO NEOANGIOGENESIS IN MALIGNANT GLIOMAS C. Schichor1, I. Teichert von Luettichau2, B. Krebs3, S. Grau1, J. Herms3, J. Tonn1, P. Nelson4, R. H. Goldbrunner1; 1Dept. Neurosurgery, Munich, Germany, 2Clinical Biochemistry, Dept. Pediatrics, Munich, Germany, 3Center for Neuropathology, Munich, Germany, 4Clinical Biochemistry, Munich, Germany Glioblastoma multiforme is an aggressive and highly vascularized tumor of the brain, with very limited mean survival time despite multimodal therapeutic treatment regimens. In this study, we evaluated the use of adult human mesenchymal stem cells (hMSC) as potential vehicles in the context of cell-based stategies for the treatment of residual tumor following surgical resection. In vitro, the cells found to be readily incorporated into growing endothelial tubes in tube formation assays using endothelial cells derived from human malignant gliomas. In vivo, hMSC showed to be actively integrated into tumor vessels of implanted human gliomas (U373) in immunodeficient rats. The use of the endothelial specific Tie2 promoter/enhancer in engineered MSC demonstrated the selective activation of the reporter gene in the context of MSC differentiation while being recruited into the neoangiogenetic vasculature of the glioma. This is the first report about hMSC, contributing to neoangiogenetic vasculature of gliomas in vitro as well as in vivo. The results suggest that human mesenchymal stem cells may provide a ready source of cells for the generation of a genetically modified cellular vector directly targeting neoangiogenetic vasculature of gliomas. Copyright 2008 by the Society for Neuro-Oncology
TI - Abstracts for the Eighth Congress of the European Association for Neuro-Oncology (EANO)
JF - Neuro-Oncology
DO - 10.1215/15228517-2008-045
DA - 2008-12-01
UR - https://www.deepdyve.com/lp/oxford-university-press/abstracts-for-the-eighth-congress-of-the-european-association-for-ZCZ6wynAZg
SP - 1061
EP - 1149
VL - 10
IS - 6
DP - DeepDyve
ER -