Radiation Oncology

Summerer, Isolde; Niyazi, Maximilian; Unger, Kristian; Pitea, Adriana; Zangen, Verena; Hess, Julia; Atkinson, Michael J; Belka, Claus; Moertl, Simone; Zitzelsberger, Horst

2015 Radiation Oncology

doi: 10.1186/s13014-015-0394-8pmid: 25903761

Kawakami, Wataru; Takemura, Akihiro; Yokoyama, Kunihiko; Nakajima, Kenichi; Yokoyama, Syoichi; Koshida, Kichiro

2015 Radiation Oncology

doi: 10.1186/s13014-014-0315-2pmid: 25567003

Abstract Background Fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) is an important method for detecting tumours, planning radiotherapy treatment, and evaluating treatment responses. However, using the standardized uptake value (SUV) threshold with PET imaging may be suitable not to determine gross tumour volume but to determine biological target volume (BTV). The aim of this study was to extract internal target volume of BTV from PET images. Methods Three spherical densities of 18F-FDG were employed in a phantom with an air or water background with repetitive motion amplitudes of 0–30 mm. The PET data were reconstructed with attenuation correction (AC) based on CT images obtained by slow CT scanning (SCS) or helical CT scanning (HCS). The errors in measured SUVmax and volumes calculated using SUV threshold values based on SUVmax (THmax) in experiments performed with varying extents of respiratory motion and AC were analysed. Results A partial volume effect (PVE) was not observed in spheres with diameters of ≥ 28 mm. When calculating SUVmax and THmax, using SCS for AC yielded smaller variance than using HCS (p < 0.05). For spheres of 37- and 28-mm diameters in the phantom with either an air or water background, significant differences were observed when mean THmax of 30-, 20-, or 10-mm amplitude were compared with the stationary conditions (p < 0.05). The average THmax values for 37-mm and 28-mm spheres with an air background were 0.362 and 0.352 in non-motion, respectively, and the mean THmax values for 37-mm and 28-mm spheres with a water background were 0.404 and 0.387 in non-motion and 0.244 and 0.263 in motion, respectively. When the phantom background was air, regardless of sphere concentration or size, THmax was dependent only on motion amplitude. Conclusions We found that there was no PVE for spheres with ≥ 28-mm diameters, and differences between SUVmax and THmax were reduced by using SCS for AC. In the head-and-neck and the abdomen, the standard values of THmax were 0.25 and 0.40 with and without respiratory movement, respectively. In the lungs, the value of THmax became the approximate expression depending on motion amplitude.

Castelli, Joel; Simon, Antoine; Louvel, Guillaume; Henry, Olivier; Chajon, Enrique; Nassef, Mohamed; Haigron, Pascal; Cazoulat, Guillaume; Ospina, Juan David; Jegoux, Franck; Benezery, Karen; de Crevoisier, Renaud

2015 Radiation Oncology

doi: 10.1186/s13014-014-0318-zpmid: 25573091

Abstract Background Large anatomical variations occur during the course of intensity-modulated radiation therapy (IMRT) for locally advanced head and neck cancer (LAHNC). The risks are therefore a parotid glands (PG) overdose and a xerostomia increase. The purposes of the study were to estimate: - the PG overdose and the xerostomia risk increase during a “standard” IMRT (IMRTstd); - the benefits of an adaptive IMRT (ART) with weekly replanning to spare the PGs and limit the risk of xerostomia. Material and methods Fifteen patients received radical IMRT (70 Gy) for LAHNC. Weekly CTs were used to estimate the dose distributions delivered during the treatment, corresponding either to the initial planning (IMRTstd) or to weekly replanning (ART). PGs dose were recalculated at the fraction, from the weekly CTs. PG cumulated doses were then estimated using deformable image registration. The following PG doses were compared: pre-treatment planned dose, per-treatment IMRTstd and ART. The corresponding estimated risks of xerostomia were also compared. Correlations between anatomical markers and dose differences were searched. Results Compared to the initial planning, a PG overdose was observed during IMRTstd for 59% of the PGs, with an average increase of 3.7 Gy (10.0 Gy maximum) for the mean dose, and of 8.2% (23.9% maximum) for the risk of xerostomia. Compared to the initial planning, weekly replanning reduced the PG mean dose for all the patients (p < 0.05). In the overirradiated PG group, weekly replanning reduced the mean dose by 5.1 Gy (12.2 Gy maximum) and the absolute risk of xerostomia by 11% (p < 0.01) (30% maximum). The PG overdose and the dosimetric benefit of replanning increased with the tumor shrinkage and the neck thickness reduction (p < 0.001). Conclusion During the course of LAHNC IMRT, around 60% of the PGs are overdosed of 4 Gy. Weekly replanning decreased the PG mean dose by 5 Gy, and therefore by 11% the xerostomia risk.

Gurka, Marie K; Chen, Leonard N; Bhagat, Aditi; Moures, Rudy; Kim, Joy S; Yung, Thomas; Lei, Siyuan; Collins, Brian T; Krishnan, Pranay; Suy, Simeng; Dritschilo, Anatoly; Lynch, John H; Collins, Sean P

2015 Radiation Oncology

doi: 10.1186/s13014-015-0351-6pmid: 25890265

Abstract Background Hematuria following prostate radiotherapy is a known toxicity that may adversely affect a patient’s quality of life. Given the higher dose of radiation per fraction using stereotactic body radiation therapy (SBRT) there is concern that post-SBRT hematuria would be more common than with alternative radiation therapy approaches. Herein, we describe the incidence and severity of hematuria following stereotactic body radiation therapy (SBRT) for prostate cancer at our institution. Methods Two hundred and eight consecutive patients with prostate cancer treated with SBRT monotherapy with at least three years of follow-up were included in this retrospective analysis. Treatment was delivered using the CyberKnife® (Accuray) to doses of 35–36.25 Gy in 5 fractions. Toxicities were scored using the CTCAE v.4. Hematuria was counted at the highest grade it occurred in the acute and late setting for each patient. Cystoscopy findings were retrospectively reviewed. Univariate and multivariate analyses were performed. Hematuria-associated bother was assessed via the Expanded Prostate Index Composite (EPIC)-26. Results The median age was 69 years with a median prostate volume of 39 cc. With a median follow-up of 48 months, 38 patients (18.3%) experienced at least one episode of hematuria. Median time to hematuria was 13.5 months. In the late period, there were three grade 3 events and five grade 2 events. There were no grade 4 or 5 events. The 3-year actuarial incidence of late hematuria ≥ grade 2 was 2.4%. On univariate analysis, prostate volume (p = 0.022) and history of prior procedure(s) for benign prostatic hypertrophy (BPH) (p = 0.002) were significantly associated with hematuria. On multivariate analysis, history of prior procedure(s) for BPH (p < 0.0001) and α1A antagonist use (p = 0.008) were significantly associated with the development of hematuria. Conclusions SBRT for prostate cancer was well tolerated with hematuria rates comparable to other radiation modalities. Patients factors associated with BPH, such as larger prostate volume, alpha antagonist usage, and prior history of procedures for BPH are at increased risk for the development of hematuria.

Rades, Dirk; Conde, Antonio J.; Garcia, Raquel; Cacicedo, Jon; Segedin, Barbara; Perpar, Ana; Schild, Steven E.

2015 Radiation Oncology

doi: 10.1186/s13014-015-0483-8pmid: 26282125

Abstract Background Elderly patients become more important in oncology. In this group, personalized treatment approaches taking into account survival prognoses and comorbidities play a major role. Predictive instruments are necessary to estimate the survival of elderly cancer patients. The importance of separate instruments for different tumor entities has been recognized. In this study, an instrument was generated to estimate the survival of elderly patients developing metastatic spinal cord compression (MSCC) from breast cancer. Methods In 218 elderly patients (age ≥65 years) irradiated for MSCC from breast cancer, nine factors were evaluated for survival: fractionation regimen, age, time from breast cancer diagnosis to RT of MSCC, visceral metastases, other bone metastases, time developing motor deficits, pre-radiotherapy ambulatory status, number of involved vertebrae, and Eastern Cooperative Oncology Group (ECOG) performance score. Factors significantly associated with survival in the Cox regression analysis were included in the prognostic instrument. Scores for each factor were calculated by dividing the 6-months survival rates by 10. The sums of these scores represented the patients’ scores. Results On multivariate analyses, visceral metastases (p < 0.001), time developing motor deficits (p < 0.001), ambulatory status (p < 0.001), number of involved vertebrae (p = 0.032), and ECOG performance score (p < 0.001) were significant and included in the prognostic instrument. Based on the patients’ scores, three groups were designed: 18–27 points, 28–39 points and 40–42 points. Six-months survival rates were 4, 62 and 100 %, respectively (p < 0.001). Conclusions This new instrument contributes to personalized treatment in elderly patients with MSCC from breast cancer by predicting an individual patient’s survival prognosis.

Yoon, Hong In; Cha, Jihye; Keum, Ki Chang; Lee, Ha Yoon; Nam, Eun Ji; Kim, Sang Wun; Kim, Sunghoon; Kim, Young Tae; Kim, Gwi Eon; Kim, Yong Bae

2015 Radiation Oncology

doi: 10.1186/s13014-014-0320-5pmid: 25582425

Abstract Purpose To review the clinical outcomes of extended-field radiation therapy (EFRT) and to analyze prognostic factors significant for survival in patients receiving EFRT for uterine cervical carcinoma with para-aortic node (PAN) metastasis. Patients and methods We retrospectively reviewed 90 patients with stage IB-IVA cervical cancer and PAN metastasis between 1987 and 2012. Median age was 50 (range, 24–77). Patients received median 70.2 Gy (range, 56–93) to point A and median 50.4 Gy (range, 45–60.4) to PAN over median 69 elapsed days (range, 43–182). Forty-six patients (51.1%) received concurrent chemotherapy. Survival was calculated using the Kaplan–Meier method. We analyzed prognostic factors for overall actuarial survival (OS) and progression-free survival (PFS) using a Cox regression method. Results The median follow-up period for surviving patients was 55 months (range, 3–252). Seventy patients (77.8%) had complete remission. Forty-six patients experienced treatment failure as follows: 11 patients (12.2%) as local recurrence, 19 (21%) as regional recurrence and 33 (36.7%) as distant metastasis. The 5-yr OS and PFS were 62.6% and 43.9%, respectively. Treatment response was the only statistically independent prognostic factors for OS (p= 0.04) and PFS (p< 0.001) on multivariate analysis. Grade 3 or 4 hematologic gastrointestinal and urogenital toxicities were observed in about 10% of patients. Conclusions Our institutional experiences showed that EFRT was an effective treatment for cervical cancer patients with PAN metastasis. The addition of chemotherapy to EFRT seems to have uncertain survival benefit with higher hematologic toxicity.

Laaksomaa, Marko; Kapanen, Mika; Haltamo, Mikko; Skyttä, Tanja; Peltola, Seppo; Hyödynmaa, Simo; Kellokumpu-Lehtinen, Pirkko-Liisa

2015 Radiation Oncology

doi: 10.1186/s13014-015-0383-ypmid: 25885270

Abstract Background Adjuvant radiotherapy (RT) of left-sided breast cancer is increasingly performed in voluntary deep inspiration breath-hold (vDIBH). The aim of this study was to estimate the reproducibility of breath-hold level (BHL) and to find optimal bony landmarks for matching of orthogonal setup images to minimise setup margins. Methods 1067 sets of images with an orthogonal setup and tangential field from 67 patients were retrospectively analysed. Residual position errors were determined in the tangential treatment field images for different matches of the setup images. Variation of patient posture and BHL were analysed for position errors of the vertebrae, clavicula, ribs and sternum in the setup and tangential field images. The BHL was controlled with a Varian RPM® system. Setup margins were calculated using the van Herk’s formula. Patients who underwent lymph node irradiation were also investigated. Results For the breast alone, the midway compromise of the ribs and sternum was the best general choice for matching of the setup images. The required margins were 6.5 mm and 5.3 mm in superior-inferior (SI) and lateral/anterior-posterior (LAT/AP) directions, respectively. With the individually optimised image matching position also including the vertebrae, slightly smaller margins of 6.0 mm and 4.8 mm were achieved, respectively. With the individually optimised match, margins of 7.5 mm and 10.8 mm should be used in LAT and SI directions, respectively, for the lymph node regions. These margins were considered too large. The reproducibility of the BHL was within 5 mm in the AP direction for 75% of patients. Conclusions The smallest setup margins were obtained when the matching position of the setup images was individually optimised for each patient. Optimal match for the breast alone is not optimal for the lymph node region, and, therefore, a threshold of 5 mm was introduced for residual position errors of the sternum, upper vertebrae, clavicula and chest wall to retain minimal setup margins of 5 mm. Because random interfraction variation in patient posture was large, we recommend daily online image guidance. The BHL should be verified with image guidance.

Moulton, Calyn R.;House, Michael J.;Lye, Victoria;Tang, Colin I.;Krawiec, Michele;Joseph, David J.;Denham, James W.;Ebert, Martin A.

2015 Radiation Oncology

doi: 10.1186/s13014-015-0563-9pmid: 26666538

Abstract Background Registering CTs for patients receiving external beam radiotherapy (EBRT) with a boost dose from high-dose-rate brachytherapy (HDR) can be challenging due to considerable image discrepancies (e.g. rectal fillings, HDR needles, HDR artefacts and HDR rectal packing materials). This study is the first to comparatively evaluate image processing and registration methods used to register the rectums in EBRT and HDR CTs of prostate cancer patients. The focus is on the rectum due to planned future analysis of rectal dose-volume response. Methods For 64 patients, the EBRT CT was retrospectively registered to the HDR CT with rigid registration and non-rigid registration methods in VelocityAI. Image processing was undertaken on the HDR CT and the rigidly-registered EBRT CT to reduce the impact of discriminating features on alternative non-rigid registration methods applied in the software suite for Deformable Image Registration and Adaptive Radiotherapy Research (DIRART) using the Horn-Schunck optical flow and Demons algorithms. The propagated EBRT-rectum structures were compared with the HDR structure using the Dice similarity coefficient (DSC), Hausdorff distance (HD) and average surface distance (ASD). The image similarity was compared using mutual information (MI) and root mean squared error (MSE). The displacement vector field was assessed via the Jacobian determinant (JAC). The post-registration alignments of rectums for 21 patients were visually assessed. Results The greatest improvement in the median DSC relative to the rigid registration result was 35 % for the Horn-Schunck algorithm with image processing. This algorithm also provided the best ASD results. The VelocityAI algorithms provided superior HD, MI, MSE and JAC results. The visual assessment indicated that the rigid plus deformable multi-pass method within VelocityAI resulted in the best rectum alignment. Conclusions The DSC, ASD and HD improved significantly relative to the rigid registration result if image processing was applied prior to DIRART non-rigid registrations, whereas VelocityAI without image processing provided significant improvements. Reliance on a single rectum structure-correspondence metric would have been misleading as the metrics were inconsistent with one another and visual assessments. It was important to calculate metrics for a restricted region covering the organ of interest. Overall, VelocityAI generated the best registrations for the rectum according to the visual assessment, HD, MI, MSE and JAC results.