EYE LENS RADIATION EXPOSURE OF WORKERS DURING MEDICAL INTERVENTIONAL PROCEDURES AND SURGERY

EYE LENS RADIATION EXPOSURE OF WORKERS DURING MEDICAL INTERVENTIONAL PROCEDURES AND SURGERY Abstract To evaluates the eye-lens radiation exposure of workers during medical interventional procedures and surgery in a military hospital as well as of the equine veterinarians. The measures represent the exposure in a normal workload schedule of ninety randomly selected workers over a 3-month period, extrapolated to 1 year. The eye-lens dosemeters were placed near the eye closest to the radiation source (Carinou, E., Ferrari, P., Bjelac, O. C., Gingaume, M., Merce, M. S. and O’Connor, U. Eye lens monitoring for interventional radiology personnel: dosemeters, calibration and practical aspects of H p (3) monitoring. A 2015 review. J. Radiol. Prot. 2015;35(3): R17–R34). Three models of eye-lens dosemeters (Dosilab, Landauer and IRSN) were assessed in term of ergonomics. The annual estimation of eye-lens doses did not reach the annual dose limit of 20 mSv revised by the ICRP, ranged from 0.00 to 18.12 mSv with a mean of 0.96 ± 2.28 mSv. However, these results cannot be representative of a heavy workload or incident situations for which radiation exposure to the eye-lens could exceed this limit. The IRSN dosemeter model was considered the most convenient. INTRODUCTION Eye lens dosimetry in interventional medical practices and surgery has been published in several clinical trials and an active debate about the causality of radiation-induced cataract is still ongoing. The eye lens is one of the most radiosensitive tissues of the human body(1); if exposed to ionising radiation it can develop radiation-induced cataract at an early age(2, 3). While Thrapsanioti et al.(4) did not observe any statistical difference between 26 interventional cardiologists and 22 unexposed individuals regarding the prevalence of either nuclear or cortical lens opacities, four interventional cardiologists in their cohort were detected with early stage subcapsular sclerosis. The annual dose received by the interventional cardiologists estimated to be between 0.7 and 11 mSv indicated that the eye lens doses can be significant(4). A contrario the study of Matsubara et al.(5) demonstrated a significant elevated prevalence of radiation-associated damages to the eye lens for interventional cardiology workers with 28.6% of posterior lens opacities for 42 interventional cardiologists, 19.5% for nurses, and 2.7% for controls. The average and range of annual equivalent dose at eye lens Hp(3) were 5.7 [0.1–35.3] mSv(5). In 2011, the International Commission on Radiological Protection (ICRP) recommended a reduction of the annual dose limit for occupational exposure of the eye lens from 150 to 20 mSv, averaged over a 5-year period, with the dose not exceeding 50 mSv in any single year(6). The reason for this change was that epidemiological studies have shown that the eye lens is more sensitive to ionising radiation than previously assumed (ICRP 118)(6). As highlighted above, compliance with this new requirement could be difficult in some workplaces such as cardiology, interventional radiology and surgery, particularly in situations leading to a heavy workload and since the number of interventional procedures (IP) are growing (UNSCEAR 2010(7)). These professional groups are known to receive the highest doses to the eyes(8). The dose to the eye lens can be assessed either by using the dose equivalent Hp(10) measured with a whole-body dosemeter worn above the protective apron near the lead collar(9), either by dedicated dosemeters allowing a more accurate estimation of radiation exposure to the eye lens in dose equivalent Hp(3)(10). The aim of present work is to assess with dedicated dosemeters the radiation dose received by the eye lens during IP and surgery in a military hospital in the fields of cardiology, radiology, surgery, gastroenterology as well as by equine veterinarians and auxiliaries serving the Republican Guard. METHODS Population Medical and paramedical (nurses and electroradiology manipulators) workers in surgery and medical IP in a military hospital were prospectively included from January to March 2017. A total of 90 workers including cardiologists, radiologists and surgeons (vascular, orthopaedic and neurosurgery) from Hospital d’Instruction des Armées (HIA) Percy, gastroenterologists from HIA Begin as well as equine veterinarians and auxiliaries serving the Republican Guard, were retained and asked to wear an eye lens dosemeter for a period of 3 months. All procedures types of each worker during the measurement period were recorded (Table 1). Standard protective measures were not modified and included keeping distances, wearing of protective lead aprons, thyroid shields and, if appropriate, protective leaded glasses. The IP were usually performed with a main operator and an assistant, who were equipped by an eye lens dosemeter. Table 1. Distribution of dosemeters in each speciality and description of interventional procedures types. IRSN Dosilab Landauer IP types Highest doses Lowest doses Radiology 4 5 5 Embolization Angioplasty Dilatation Biopsy  Radiologist 1 2 1  ERM 3 3 4 Cardiology 3 5 4 Coronarography Ablation/implantation of pacemakers/defibrillators  Cardiologist 1 3 3  Nurses 2 2 1 Surgery 10 17 17 Vertebroplasty Laminectomy Catheter implantation Pontage  Vascular surgeon 2 3 1  Orthopaedic surgeon 1 1 2  Neuro surgeon 2 2 2  Surgery nurses 3 8 9  Anesthesiology nurses 2 3 3 Gastroenterology 1 1 4 Prostheses Cholangiography Dilatation  Gastroenterologist 1 1 2  nurses 0 0 2 Equin veterinarian 11 0 0 Limb radiography  Veterinarian 5 0 0  Auxiliary veterinarian 6 0 0 Total 29 28 30 IRSN Dosilab Landauer IP types Highest doses Lowest doses Radiology 4 5 5 Embolization Angioplasty Dilatation Biopsy  Radiologist 1 2 1  ERM 3 3 4 Cardiology 3 5 4 Coronarography Ablation/implantation of pacemakers/defibrillators  Cardiologist 1 3 3  Nurses 2 2 1 Surgery 10 17 17 Vertebroplasty Laminectomy Catheter implantation Pontage  Vascular surgeon 2 3 1  Orthopaedic surgeon 1 1 2  Neuro surgeon 2 2 2  Surgery nurses 3 8 9  Anesthesiology nurses 2 3 3 Gastroenterology 1 1 4 Prostheses Cholangiography Dilatation  Gastroenterologist 1 1 2  nurses 0 0 2 Equin veterinarian 11 0 0 Limb radiography  Veterinarian 5 0 0  Auxiliary veterinarian 6 0 0 Total 29 28 30 ERM = electo-radiology manipulators, IP = interventional procedure. Data are expressed as number of subjects. Table 1. Distribution of dosemeters in each speciality and description of interventional procedures types. IRSN Dosilab Landauer IP types Highest doses Lowest doses Radiology 4 5 5 Embolization Angioplasty Dilatation Biopsy  Radiologist 1 2 1  ERM 3 3 4 Cardiology 3 5 4 Coronarography Ablation/implantation of pacemakers/defibrillators  Cardiologist 1 3 3  Nurses 2 2 1 Surgery 10 17 17 Vertebroplasty Laminectomy Catheter implantation Pontage  Vascular surgeon 2 3 1  Orthopaedic surgeon 1 1 2  Neuro surgeon 2 2 2  Surgery nurses 3 8 9  Anesthesiology nurses 2 3 3 Gastroenterology 1 1 4 Prostheses Cholangiography Dilatation  Gastroenterologist 1 1 2  nurses 0 0 2 Equin veterinarian 11 0 0 Limb radiography  Veterinarian 5 0 0  Auxiliary veterinarian 6 0 0 Total 29 28 30 IRSN Dosilab Landauer IP types Highest doses Lowest doses Radiology 4 5 5 Embolization Angioplasty Dilatation Biopsy  Radiologist 1 2 1  ERM 3 3 4 Cardiology 3 5 4 Coronarography Ablation/implantation of pacemakers/defibrillators  Cardiologist 1 3 3  Nurses 2 2 1 Surgery 10 17 17 Vertebroplasty Laminectomy Catheter implantation Pontage  Vascular surgeon 2 3 1  Orthopaedic surgeon 1 1 2  Neuro surgeon 2 2 2  Surgery nurses 3 8 9  Anesthesiology nurses 2 3 3 Gastroenterology 1 1 4 Prostheses Cholangiography Dilatation  Gastroenterologist 1 1 2  nurses 0 0 2 Equin veterinarian 11 0 0 Limb radiography  Veterinarian 5 0 0  Auxiliary veterinarian 6 0 0 Total 29 28 30 ERM = electo-radiology manipulators, IP = interventional procedure. Data are expressed as number of subjects. The study was carried out in accordance with the ethical Declaration of Helsinki. All persons gave their informed consent prior to their inclusion in the study. Dosemeters The assessment of eye lens radiation exposure of workers was performed with dedicated eye lens dosemeters, calibrated in terms of Hp(3) corresponding to the personal dose equivalent to the eye lens at a depth of 3 mm. The three main manufacturers in France commercialising this dosemeter type (Landauer, Dosilab and IRSN laboratories) were tested using an equal number of each per month (n = 30). The eye lens dosemeter consists of an individual thermoluminescent detector used for occupational dosimetry with sufficient filtration and a holder to help the dosemeter to be placed as close as possible to the eye lens (Figure 1). Alongside the dosemeters used for eye lens dose monitoring, one unused dosemeter of each manufacturer was analysed for subsequent background radiation subtraction. Figure 1. View largeDownload slide The three dosemeters models. (A) Dosilab model is like a clamp to put on the cap. (B) Landauer model, presents as a little hook fixing on the cap. (C) IRSN model, wearing like a headband. Figure 1. View largeDownload slide The three dosemeters models. (A) Dosilab model is like a clamp to put on the cap. (B) Landauer model, presents as a little hook fixing on the cap. (C) IRSN model, wearing like a headband. The eye lens dosemeters were positioned on the temple close to the right or left eye, on the side of the head receiving the highest dose(10). In cases where leaded glasses were worn, the dosemeters were placed on the outside of the protective shield on the bezel branch. The measured radiation exposure represented the exposure in a normal working schedule of a randomly selected workers over a 3-month period and this cumulative eye lens dose was extrapolated to a 1-year period. Ergonomic assessment Workers wearing the dosemeters were asked to assess the ergonomics of the eye lens dosemeters based on losses, discomfort, difficulties, falls and sterility risks to the surgical field. Each of the three models of dosemeter (Landauer, Dosilab and IRSN) was assessed (Figure 1). The number of workers favourable to wearing the tested dedicated dosemeter was also reported. Statistical analysis Continuous variables were expressed by their means ± standard deviation (SD) or medians and range [min–max]. Categorical variables were expressed as numbers and percentages. RESULTS Population Overall, 87 workers wore the eye lens dosemeter during their normal working schedule (Table 1). Three dosemeters were not assigned. The cardiology IP mainly included coronarographies, removal of material, implementation of pacemakers or defibrillators; that was for radiology endovascular procedures, biopsies, infiltrations and embolization; limb fractures and vertebroplasties for surgery; dilatations, implementation of prostheses and cholangiographies for gastroenterology (Table 1). Dosimetry A total of 64 dosemeters were analysed. The remaining 23 (IRSN = 5, Dosilab = 11, Landauer = 7) were not worn throughout the entire study period due to losses, one sick leave (vascular surgeon), and six dosemeters which were not rendered at the end of the study (vascular surgeons). Details of dosimetry results are summarised in Tables 2 for the 3-month period and Table 3 for the extrapolation to 1 year. The estimated annual eye lens radiation exposure ranges from a minimum of 0.00 mSv to a maximum of 18.12 mSv with an average dose of 0.96 ± 2.28 mSv if the use of leaded glasses is not taken into consideration. The maximal value of 18.12 mSv related to a cardiologist. The lowest average doses concerns gastroenterology 0.22 ± 0.54 mSv while the highest concerns cardiology 4.06 ± 6.19 mSv. Overall, the period studied did not correspond to a heavy workload and no incidental procedure was reported. This period was particularly sparse in terms of radiological interventions for the equine veterinarians and auxiliaries who are known to receive high levels of ionising radiation due to the animals’ high mass. The mean number of IP per 3 months in gastroenterolgy was 8 by worker, 21 for radiology, 24 for cardiology and 12 for surgery. An extrapolation of the present results to a heavier workload level, twice more, lead to a mean dose of 0.44 (max 2.64) mSv for gastroenterology, 1.16 (max 4.64) mSv for radiology, 8.12 (max 36.24) mSv for cardiology, 1.08 (max 8.88) mSv for surgery and 3.14 (max 4.16) mSv for equin veterinarians. Table 2. Results of dosimetry (Hp(3)) according to speciality over a 3-month period. 3 Months Mean ± SD (mSv) Median [min–max] (mSv) Radiology 0.14 ± 0.18 0.09 [0.00–0.58] Cardiology 1.02 ± 1.55 0.38 [0.00–4.53] Surgery 0.13 ± 0.22 0.00 [0.00–1.11] Gastroenterology 0.06 ± 0.13 0.00 [0.00–0.33] Equine veterinarian 0.39 ± 0.09 0.37 [0.25–0.52] Total 0.27 ± 0.60 0.18 [0.00–4.53] Controls, n = 3 0.22 ± 0.19 0.33 [0.00–0.33] 3 Months Mean ± SD (mSv) Median [min–max] (mSv) Radiology 0.14 ± 0.18 0.09 [0.00–0.58] Cardiology 1.02 ± 1.55 0.38 [0.00–4.53] Surgery 0.13 ± 0.22 0.00 [0.00–1.11] Gastroenterology 0.06 ± 0.13 0.00 [0.00–0.33] Equine veterinarian 0.39 ± 0.09 0.37 [0.25–0.52] Total 0.27 ± 0.60 0.18 [0.00–4.53] Controls, n = 3 0.22 ± 0.19 0.33 [0.00–0.33] SD = standard deviation, mSv = millisievert, min = minimale value, max = maximale value, Hp(3) = personal dose equivalent to the eye-lens at a depth of 3 mm. Table 2. Results of dosimetry (Hp(3)) according to speciality over a 3-month period. 3 Months Mean ± SD (mSv) Median [min–max] (mSv) Radiology 0.14 ± 0.18 0.09 [0.00–0.58] Cardiology 1.02 ± 1.55 0.38 [0.00–4.53] Surgery 0.13 ± 0.22 0.00 [0.00–1.11] Gastroenterology 0.06 ± 0.13 0.00 [0.00–0.33] Equine veterinarian 0.39 ± 0.09 0.37 [0.25–0.52] Total 0.27 ± 0.60 0.18 [0.00–4.53] Controls, n = 3 0.22 ± 0.19 0.33 [0.00–0.33] 3 Months Mean ± SD (mSv) Median [min–max] (mSv) Radiology 0.14 ± 0.18 0.09 [0.00–0.58] Cardiology 1.02 ± 1.55 0.38 [0.00–4.53] Surgery 0.13 ± 0.22 0.00 [0.00–1.11] Gastroenterology 0.06 ± 0.13 0.00 [0.00–0.33] Equine veterinarian 0.39 ± 0.09 0.37 [0.25–0.52] Total 0.27 ± 0.60 0.18 [0.00–4.53] Controls, n = 3 0.22 ± 0.19 0.33 [0.00–0.33] SD = standard deviation, mSv = millisievert, min = minimale value, max = maximale value, Hp(3) = personal dose equivalent to the eye-lens at a depth of 3 mm. Table 3. Results of dosimetry (Hp(3)) according to speciality extrapolated over a 1-year period. Extrapolation to 1 year Mean ± SD (mSv) Median [min–max] (mSv) Radiology 0.58 ± 0.72 0.35 [0.00–2.32] Cardiology 4.06 ± 6.19 1.50 [0.00–18.12] Surgery 0.54 ± 0.88 0.00 [0.00–4.44] Gastroenterology 0.22 ± 0.54 0.00 [0.00–1.32] Equine veterinarian 1.57 ± 0.36 1.48 [1.00–2.08] Total 0.96 ± 2.28 0.20 [0.00–18.12] Controls, n = 3 0.87 ± 0.76 1.03 [0.00–1.32] Extrapolation to 1 year Mean ± SD (mSv) Median [min–max] (mSv) Radiology 0.58 ± 0.72 0.35 [0.00–2.32] Cardiology 4.06 ± 6.19 1.50 [0.00–18.12] Surgery 0.54 ± 0.88 0.00 [0.00–4.44] Gastroenterology 0.22 ± 0.54 0.00 [0.00–1.32] Equine veterinarian 1.57 ± 0.36 1.48 [1.00–2.08] Total 0.96 ± 2.28 0.20 [0.00–18.12] Controls, n = 3 0.87 ± 0.76 1.03 [0.00–1.32] SD = standard deviation, mSv = millisievert, min = minimale value, max = maximale value, Hp(3) = personal dose equivalent to the eye-lens at 3 mm depth. Table 3. Results of dosimetry (Hp(3)) according to speciality extrapolated over a 1-year period. Extrapolation to 1 year Mean ± SD (mSv) Median [min–max] (mSv) Radiology 0.58 ± 0.72 0.35 [0.00–2.32] Cardiology 4.06 ± 6.19 1.50 [0.00–18.12] Surgery 0.54 ± 0.88 0.00 [0.00–4.44] Gastroenterology 0.22 ± 0.54 0.00 [0.00–1.32] Equine veterinarian 1.57 ± 0.36 1.48 [1.00–2.08] Total 0.96 ± 2.28 0.20 [0.00–18.12] Controls, n = 3 0.87 ± 0.76 1.03 [0.00–1.32] Extrapolation to 1 year Mean ± SD (mSv) Median [min–max] (mSv) Radiology 0.58 ± 0.72 0.35 [0.00–2.32] Cardiology 4.06 ± 6.19 1.50 [0.00–18.12] Surgery 0.54 ± 0.88 0.00 [0.00–4.44] Gastroenterology 0.22 ± 0.54 0.00 [0.00–1.32] Equine veterinarian 1.57 ± 0.36 1.48 [1.00–2.08] Total 0.96 ± 2.28 0.20 [0.00–18.12] Controls, n = 3 0.87 ± 0.76 1.03 [0.00–1.32] SD = standard deviation, mSv = millisievert, min = minimale value, max = maximale value, Hp(3) = personal dose equivalent to the eye-lens at 3 mm depth. Ergonomics The dosemeter assessed as the least uncomfortable to wear was the IRSN model due to its stability, limiting losses and risks of falling onto the surgical field. It was also rarely forgotten due to its size and fixing type. However, it was considered as being painful to wear at times (Table 4). Overall, 50% of the medical staff estimates that the Landauer dosemeter model fall, also it was judged to present a sterility risk. The Dosilab dosemeter model was considered as uncomfortable in 60% of cases resulting on inconvenient to wear daily. Table 4. Ergonomics assessment of the three dosemeters models tested (Dosilab, Landauer and IRSN). Dosilab Landauer IRSN Number of responses 10 10 18 Forgotten on headband/trash 3 (30%) 4 (40%) 4 (22%) Recover after forgotten 2 (20%) 6 (60%) 3 (17%) Discomforts 6 (60%) 6 (60%) 7 (39%) Difficulties  Falls NR 5 (50%) NR  Sterility risks NR 2 (20%) NR  Forgetfulness 3 (30%) 2 (20%) 1 (5.6%)  Inconvenient 4 (40%) NR 7 (39%) Favourable to wearing 4 (40%) 6 (60%) 13 (72%) Dosilab Landauer IRSN Number of responses 10 10 18 Forgotten on headband/trash 3 (30%) 4 (40%) 4 (22%) Recover after forgotten 2 (20%) 6 (60%) 3 (17%) Discomforts 6 (60%) 6 (60%) 7 (39%) Difficulties  Falls NR 5 (50%) NR  Sterility risks NR 2 (20%) NR  Forgetfulness 3 (30%) 2 (20%) 1 (5.6%)  Inconvenient 4 (40%) NR 7 (39%) Favourable to wearing 4 (40%) 6 (60%) 13 (72%) NR = not reported. Data are expressed as numbers and percentages of subjects. Table 4. Ergonomics assessment of the three dosemeters models tested (Dosilab, Landauer and IRSN). Dosilab Landauer IRSN Number of responses 10 10 18 Forgotten on headband/trash 3 (30%) 4 (40%) 4 (22%) Recover after forgotten 2 (20%) 6 (60%) 3 (17%) Discomforts 6 (60%) 6 (60%) 7 (39%) Difficulties  Falls NR 5 (50%) NR  Sterility risks NR 2 (20%) NR  Forgetfulness 3 (30%) 2 (20%) 1 (5.6%)  Inconvenient 4 (40%) NR 7 (39%) Favourable to wearing 4 (40%) 6 (60%) 13 (72%) Dosilab Landauer IRSN Number of responses 10 10 18 Forgotten on headband/trash 3 (30%) 4 (40%) 4 (22%) Recover after forgotten 2 (20%) 6 (60%) 3 (17%) Discomforts 6 (60%) 6 (60%) 7 (39%) Difficulties  Falls NR 5 (50%) NR  Sterility risks NR 2 (20%) NR  Forgetfulness 3 (30%) 2 (20%) 1 (5.6%)  Inconvenient 4 (40%) NR 7 (39%) Favourable to wearing 4 (40%) 6 (60%) 13 (72%) NR = not reported. Data are expressed as numbers and percentages of subjects. DISCUSSION The eye lens is one of the most radiosensitive tissues of the human body(1); if exposed to ionising radiation it can develop radiation-induced cataract at an early age(2). The dose to the eye lens can be assessed using the dose equivalent Hp(10) measured with a whole-body dosemeter worn above the protective apron near the lead collar(9). However, dedicated dosemeters allow a more accurate estimation of radiation exposure to the eye lens in dose equivalent Hp(3) corresponding to the personal dose equivalent to the eye lens at a depth of 3 mm(10). The present study demonstrates that medical and paramedical workers exposed to ionising radiation in a military hospital during surgery and IP of cardiology, radiology and gastroenterology as well as equine veterinarians and auxiliaries had an estimated annual eye lens dose below the revised ICRP’s limit of 20 mSv/y, with the highest doses for cardiology 4.06 ± 6.19 mSv (maximal value of 18.12 mSv) and lowest for gastroenterology 0.22 ± 0.54 mSv (maximal value of 1.32 mSv). Nonetheless, these results correspond to a normal workload and cannot be extrapolated to those of a heavy workload or those in incident situations. Moreover, considering that protective glasses were used for some workers the estimated dose to the eye lens of the present study could reach or exceed the ICRP’s limit(11, 12). Vaes et al.(13) had prospectively investigated the radiation exposure of 16 anesthesiologists during a routine year of professional activity. The exposure was extrapolated from 1-month cumulative eye lens dose in a normal working schedule including neuro-embolization, radiofrequency ablation, vertebroplasty and kyphoplasty. The estimated annual eye lens doses range from 0.4 to 3.5 mSv with an average dose of 1.3 mSv. The highest maximum and average doses were for neuroembolization, cardiac ablation and vertebra/kyphoplasty procedures(13). In line with the present results, cardiology IP were found to have the highest doses, while radiological IP of the present study, not specifically focused on neuroembolization, demonstrated to have less important mean dose values (0.58 ± 0.72 mSv). Indeed Koukorava et al.(14) during radiological IP found higher dose values for therapeutic procedures, especially embolization. The maximal recorded eye lens dose during a single procedure was 2.4 mSv for brain embolization. The annual doses estimated for the operator with the highest workload according to the measurement was 49.3 mSv to the eye lens(14). In the same way, Urboniene et al.(9) had assessed the eye lens doses of 50 workers during radiology IP. If the use of leaded glasses is not taken into account, the estimated maximum annual dose equivalent to the lens of the eye was 82 mSv for a cardiology procedure(9). These above mentioned studies demonstrate that the annual ICRP’s dose limit can largely be exceeded in the spectrum of cardiology and therapeutic radiology IP particularly for the main operator(9, 14). The conclusion of the 129 cardiologists cohort of the ‘Occupational Cataracts and Lens Opacities in interventional Cardiology’(15) was that after several years of practice, without eye protection, the dose may exceed the new ICRP lifetime eye threshold of 500 mSv. For work over an average period of 22 years, the estimated cumulative eye lens dose ranges from 25 mSv to more than 1600 mSv with a mean of 423 ± 359 mSv. Strengthening the results of the present study, interventional cardiologists are considered by Jacob et al.(15) at high risk of developing early radiation-induced cataracts(15). In the field of surgery, Romanova et al.(16) assessing the radiation dose to the eye lens of orthopaedic surgeons demonstrated that for fractura femoris, from an extrapolation to one procedure value, at a normal workload, the estimated mean annual dose values (10.9 mSv, min 4.7–max 17.7) did not exceed the annual occupational dose limit, while at a heavy workload it could be achieved or exceed (21.7 mSv, min 9.5–max 35.5). They demonstrated also with phantom measurements that the use of half-dose mode could reduce the dose to the eye lens of the operator(16). While not specifically focused on fractura femoris the annual estimated mean dose to the eye lens of surgery procedures in the present study shows clearly lower values (0.54 mSv, min 0.00–max 4.44) at a normal workload as well as at a heavier twice more workload 1.08 (max 8.88) mSv. Recently Suzuki et al.(12) reported a maximum equivalent dose to the eye lens at 0.8 mSv/month during orthopaedic surgery using an C-Arm X-ray system. Moreover, they identified that the leaded glasses reduced exposure by ~60%(12). Consequently if the physicians of the present study wear the leaded glasses, the highest dose of 18.12 mSv should be reduced to 7.20 mSv per year that is very far from the annual dose limit at a normal workload schedule. The results of the present study demonstrate that the maximal estimated annual eye lens radiation exposure can be close to 20 mSv for cardiologists at a normal workload, while for others specialities in particular radiology and surgery as well as equin veterinarians this maximal value is far. Based on these results and those previously published, eye lens dose monitoring of workers during IP appears to be necessary, especially in cardiology and a fortiori in others specialities according to the type of procedure and the workload level considered. Indeed one major limitation of the present study lies on the dose values obtained from a normal workload schedule over a 3-month period that cannot be strictly representative of a 1-year period, which may include a heavier workload or incident situations. Consequently, training workers exposed to ionising radiations is strongly recommended. The use of personal radiation protection equipment is also highly encouraged without additional reinforcement. CONCLUSION At a normal workload level, the estimated annual dose received by the eye lens of workers did not reach the revised ICRP annual dose limit of 20 mSv. At a heavy workload level (twice more) or maybe in incident situations the exposure could exceed this limit, reaching 36.24 mSv for a cardiologist. Monitoring eye lens radiation exposure of workers during IP may be necessary in addition to training about the risks of ionising radiations and the wearing of standard personal radiation protection equipment without additional enhancement. ACKNOWLEDGEMENTS IRSN, Dosilab and Landauer laboratories. The departments of surgery, radiology and cardiology of HIA Percy, the department of gastroenterology of HIA Begin and the equine veterinarians and auxiliaries serving the Republican Guard. M.E.R.C.N. Céline Darve. FUNDING This research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors. We declare no competing interests. REFERENCES 1 Poppe , E. Experimental investigations on cataract formation following whole-body roentgen irradiation . Acta Radiol. 47 ( 2 ), 138 – 148 ( 1957 ). Google Scholar CrossRef Search ADS PubMed 2 Ainsbury , E. A. et al. . Ionizing radiation induced cataracts: recent biological and mechanistic developments and perspectives for future research . Mutat. Res. 770 ( Pt B ), 238 – 261 ( 2016 ). Google Scholar CrossRef Search ADS PubMed 3 Bouffler , S. , Ainsbury , E. , Gilvin , P. and Harrison , J. Radiation-induced cataracts: the Health Protection Agency’s response to the ICRP statement on tissue reactions and recommendation on the dose limit for the eye lens . J. Radiol. Prot. 32 ( 4 ), 479 – 488 ( 2012 ). Google Scholar CrossRef Search ADS PubMed 4 Thrapsanioti , Z. , Askounis , P. , Datseris , I. , Diamanti , R. A. , Papathanasiou , M. and Carinou , E. Eye lens radiation exposure in Greek Interventional Cardiology Article . Radiat. Prot. Dosim. 175 ( 3 ), 344 – 356 ( 2017 ). 5 Matsubara , K. , Lertsuwunseri , V. , Srimahachota , S. , Krisanachinda , A. , Tulvatana , W. , Khambhiphant , B. , Sudchai , W. and Rehani , M. Eye lens dosimetry and the study on radiation cataract in interventional cardiologists . Phys. Med. 44 , 232 – 235 ( 2017 ). Google Scholar CrossRef Search ADS PubMed 6 Authors on behalf of ICRP , Stewart , F. A. , Akleyev , A. V. , Hauer-Jensen , M. , Hendry , J. H. , Kleiman , N. J. , Macvittie , T. J. , Aleman , B. M. , Edgar , A. B. , Mabuchi , K. et al. . ICRP publication 118: ICRP statement on tissue reactions/early and late effects of radiation in normal tissues and organs—threshold doses for tissue reactions in a radiation protection context . Ann. ICRP 41 ( 1–2 ), 1 – 322 ( 2012 ). Google Scholar CrossRef Search ADS PubMed 7 2008, U. Sources and effects of ionizing radiation ( 2010 ). 8 Kim , K. P. , Miller , D. L. , Balter , S. , Kleinerman , R. A. , Linet , M. S. , Kwon , D. and Simon , S. L. Occupational radiation doses to operators performing cardiac catheterization procedures . Health Phys. 94 ( 3 ), 211 – 227 ( 2008 ). Google Scholar CrossRef Search ADS PubMed 9 Urboniene , A. , Sadzeviciene , E. and Ziliukas , J. Assessment of eye lens doses for workers during interventional radiology procedures . Radiat. Prot. Dosim. 165 ( 1–4 ), 299 – 303 ( 2015 ). Google Scholar CrossRef Search ADS 10 Carinou , E. , Ferrari , P. , Bjelac , O. C. , Gingaume , M. , Merce , M. S. and O’Connor , U. Eye lens monitoring for interventional radiology personnel: dosemeters, calibration and practical aspects of Hp(3) monitoring. A 2015 review . J. Radiol. Prot. 35 ( 3 ), R17 – R34 ( 2015 ). Google Scholar CrossRef Search ADS PubMed 11 Hu , P. , Kong , Y. , Chen , B. , Liu , Q. , Zhuo , W. and Liu , H. Shielding effect of lead glasses on radiologists’ eye lens exposure in interventional procedures . Radiat. Prot. Dosim. 174 ( 1 ), 136 – 140 ( 2017 ). 12 Suzuki , A. , Matsubara , K. and Sasa , Y. Measurement of radiation doses to the eye lens during orthopedic surgery using an C-arm X-ray system . Radiat. Prot. Dosim. 1 – 7 ( 2017 ). doi: 10.1093/rpd/ncx250. 13 Vaes , B. , Van Keer , K. , Struelens , L. , Schoonjans , W. , Nijs , I. , Vandevenne , J. and Van Poucke , S. Eye lens dosimetry in anesthesiology: a prospective study . J. Clin. Monit. Comput. 31 ( 2 ), 303 – 308 ( 2017 ). Google Scholar CrossRef Search ADS PubMed 14 Koukorava , C. , Carinou , E. , Simantirakis , G. , Vrachliotis , T. G. , Archontakis , E. , Tierris , C. and Dimitriou , P. Doses to operators during interventional radiology procedures: focus on eye lens and extremity dosimetry . Radiat. Prot. Dosim. 144 ( 1–4 ), 482 – 486 ( 2011 ). Google Scholar CrossRef Search ADS 15 Jacob , S. , Donadille , L. , Maccia , C. , Bar , O. , Boveda , S. , Laurier , D. and Bernier , M. O. Eye lens radiation exposure to interventional cardiologists: a retrospective assessment of cumulative doses . Radiat. Prot. Dosim. 153 ( 3 ), 282 – 293 ( 2013 ). Google Scholar CrossRef Search ADS 16 Romanova , K. , Vassileva , J. and Alyakov , M. Radiation exposure to the eye lens of orthopaedic surgeons during various orthopaedic procedures . Radiat. Prot. Dosim. 165 ( 1–4 ), 310 – 313 ( 2015 ). Google Scholar CrossRef Search ADS © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/about_us/legal/notices) http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Radiation Protection Dosimetry Oxford University Press

EYE LENS RADIATION EXPOSURE OF WORKERS DURING MEDICAL INTERVENTIONAL PROCEDURES AND SURGERY

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0144-8420
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Abstract

Abstract To evaluates the eye-lens radiation exposure of workers during medical interventional procedures and surgery in a military hospital as well as of the equine veterinarians. The measures represent the exposure in a normal workload schedule of ninety randomly selected workers over a 3-month period, extrapolated to 1 year. The eye-lens dosemeters were placed near the eye closest to the radiation source (Carinou, E., Ferrari, P., Bjelac, O. C., Gingaume, M., Merce, M. S. and O’Connor, U. Eye lens monitoring for interventional radiology personnel: dosemeters, calibration and practical aspects of H p (3) monitoring. A 2015 review. J. Radiol. Prot. 2015;35(3): R17–R34). Three models of eye-lens dosemeters (Dosilab, Landauer and IRSN) were assessed in term of ergonomics. The annual estimation of eye-lens doses did not reach the annual dose limit of 20 mSv revised by the ICRP, ranged from 0.00 to 18.12 mSv with a mean of 0.96 ± 2.28 mSv. However, these results cannot be representative of a heavy workload or incident situations for which radiation exposure to the eye-lens could exceed this limit. The IRSN dosemeter model was considered the most convenient. INTRODUCTION Eye lens dosimetry in interventional medical practices and surgery has been published in several clinical trials and an active debate about the causality of radiation-induced cataract is still ongoing. The eye lens is one of the most radiosensitive tissues of the human body(1); if exposed to ionising radiation it can develop radiation-induced cataract at an early age(2, 3). While Thrapsanioti et al.(4) did not observe any statistical difference between 26 interventional cardiologists and 22 unexposed individuals regarding the prevalence of either nuclear or cortical lens opacities, four interventional cardiologists in their cohort were detected with early stage subcapsular sclerosis. The annual dose received by the interventional cardiologists estimated to be between 0.7 and 11 mSv indicated that the eye lens doses can be significant(4). A contrario the study of Matsubara et al.(5) demonstrated a significant elevated prevalence of radiation-associated damages to the eye lens for interventional cardiology workers with 28.6% of posterior lens opacities for 42 interventional cardiologists, 19.5% for nurses, and 2.7% for controls. The average and range of annual equivalent dose at eye lens Hp(3) were 5.7 [0.1–35.3] mSv(5). In 2011, the International Commission on Radiological Protection (ICRP) recommended a reduction of the annual dose limit for occupational exposure of the eye lens from 150 to 20 mSv, averaged over a 5-year period, with the dose not exceeding 50 mSv in any single year(6). The reason for this change was that epidemiological studies have shown that the eye lens is more sensitive to ionising radiation than previously assumed (ICRP 118)(6). As highlighted above, compliance with this new requirement could be difficult in some workplaces such as cardiology, interventional radiology and surgery, particularly in situations leading to a heavy workload and since the number of interventional procedures (IP) are growing (UNSCEAR 2010(7)). These professional groups are known to receive the highest doses to the eyes(8). The dose to the eye lens can be assessed either by using the dose equivalent Hp(10) measured with a whole-body dosemeter worn above the protective apron near the lead collar(9), either by dedicated dosemeters allowing a more accurate estimation of radiation exposure to the eye lens in dose equivalent Hp(3)(10). The aim of present work is to assess with dedicated dosemeters the radiation dose received by the eye lens during IP and surgery in a military hospital in the fields of cardiology, radiology, surgery, gastroenterology as well as by equine veterinarians and auxiliaries serving the Republican Guard. METHODS Population Medical and paramedical (nurses and electroradiology manipulators) workers in surgery and medical IP in a military hospital were prospectively included from January to March 2017. A total of 90 workers including cardiologists, radiologists and surgeons (vascular, orthopaedic and neurosurgery) from Hospital d’Instruction des Armées (HIA) Percy, gastroenterologists from HIA Begin as well as equine veterinarians and auxiliaries serving the Republican Guard, were retained and asked to wear an eye lens dosemeter for a period of 3 months. All procedures types of each worker during the measurement period were recorded (Table 1). Standard protective measures were not modified and included keeping distances, wearing of protective lead aprons, thyroid shields and, if appropriate, protective leaded glasses. The IP were usually performed with a main operator and an assistant, who were equipped by an eye lens dosemeter. Table 1. Distribution of dosemeters in each speciality and description of interventional procedures types. IRSN Dosilab Landauer IP types Highest doses Lowest doses Radiology 4 5 5 Embolization Angioplasty Dilatation Biopsy  Radiologist 1 2 1  ERM 3 3 4 Cardiology 3 5 4 Coronarography Ablation/implantation of pacemakers/defibrillators  Cardiologist 1 3 3  Nurses 2 2 1 Surgery 10 17 17 Vertebroplasty Laminectomy Catheter implantation Pontage  Vascular surgeon 2 3 1  Orthopaedic surgeon 1 1 2  Neuro surgeon 2 2 2  Surgery nurses 3 8 9  Anesthesiology nurses 2 3 3 Gastroenterology 1 1 4 Prostheses Cholangiography Dilatation  Gastroenterologist 1 1 2  nurses 0 0 2 Equin veterinarian 11 0 0 Limb radiography  Veterinarian 5 0 0  Auxiliary veterinarian 6 0 0 Total 29 28 30 IRSN Dosilab Landauer IP types Highest doses Lowest doses Radiology 4 5 5 Embolization Angioplasty Dilatation Biopsy  Radiologist 1 2 1  ERM 3 3 4 Cardiology 3 5 4 Coronarography Ablation/implantation of pacemakers/defibrillators  Cardiologist 1 3 3  Nurses 2 2 1 Surgery 10 17 17 Vertebroplasty Laminectomy Catheter implantation Pontage  Vascular surgeon 2 3 1  Orthopaedic surgeon 1 1 2  Neuro surgeon 2 2 2  Surgery nurses 3 8 9  Anesthesiology nurses 2 3 3 Gastroenterology 1 1 4 Prostheses Cholangiography Dilatation  Gastroenterologist 1 1 2  nurses 0 0 2 Equin veterinarian 11 0 0 Limb radiography  Veterinarian 5 0 0  Auxiliary veterinarian 6 0 0 Total 29 28 30 ERM = electo-radiology manipulators, IP = interventional procedure. Data are expressed as number of subjects. Table 1. Distribution of dosemeters in each speciality and description of interventional procedures types. IRSN Dosilab Landauer IP types Highest doses Lowest doses Radiology 4 5 5 Embolization Angioplasty Dilatation Biopsy  Radiologist 1 2 1  ERM 3 3 4 Cardiology 3 5 4 Coronarography Ablation/implantation of pacemakers/defibrillators  Cardiologist 1 3 3  Nurses 2 2 1 Surgery 10 17 17 Vertebroplasty Laminectomy Catheter implantation Pontage  Vascular surgeon 2 3 1  Orthopaedic surgeon 1 1 2  Neuro surgeon 2 2 2  Surgery nurses 3 8 9  Anesthesiology nurses 2 3 3 Gastroenterology 1 1 4 Prostheses Cholangiography Dilatation  Gastroenterologist 1 1 2  nurses 0 0 2 Equin veterinarian 11 0 0 Limb radiography  Veterinarian 5 0 0  Auxiliary veterinarian 6 0 0 Total 29 28 30 IRSN Dosilab Landauer IP types Highest doses Lowest doses Radiology 4 5 5 Embolization Angioplasty Dilatation Biopsy  Radiologist 1 2 1  ERM 3 3 4 Cardiology 3 5 4 Coronarography Ablation/implantation of pacemakers/defibrillators  Cardiologist 1 3 3  Nurses 2 2 1 Surgery 10 17 17 Vertebroplasty Laminectomy Catheter implantation Pontage  Vascular surgeon 2 3 1  Orthopaedic surgeon 1 1 2  Neuro surgeon 2 2 2  Surgery nurses 3 8 9  Anesthesiology nurses 2 3 3 Gastroenterology 1 1 4 Prostheses Cholangiography Dilatation  Gastroenterologist 1 1 2  nurses 0 0 2 Equin veterinarian 11 0 0 Limb radiography  Veterinarian 5 0 0  Auxiliary veterinarian 6 0 0 Total 29 28 30 ERM = electo-radiology manipulators, IP = interventional procedure. Data are expressed as number of subjects. The study was carried out in accordance with the ethical Declaration of Helsinki. All persons gave their informed consent prior to their inclusion in the study. Dosemeters The assessment of eye lens radiation exposure of workers was performed with dedicated eye lens dosemeters, calibrated in terms of Hp(3) corresponding to the personal dose equivalent to the eye lens at a depth of 3 mm. The three main manufacturers in France commercialising this dosemeter type (Landauer, Dosilab and IRSN laboratories) were tested using an equal number of each per month (n = 30). The eye lens dosemeter consists of an individual thermoluminescent detector used for occupational dosimetry with sufficient filtration and a holder to help the dosemeter to be placed as close as possible to the eye lens (Figure 1). Alongside the dosemeters used for eye lens dose monitoring, one unused dosemeter of each manufacturer was analysed for subsequent background radiation subtraction. Figure 1. View largeDownload slide The three dosemeters models. (A) Dosilab model is like a clamp to put on the cap. (B) Landauer model, presents as a little hook fixing on the cap. (C) IRSN model, wearing like a headband. Figure 1. View largeDownload slide The three dosemeters models. (A) Dosilab model is like a clamp to put on the cap. (B) Landauer model, presents as a little hook fixing on the cap. (C) IRSN model, wearing like a headband. The eye lens dosemeters were positioned on the temple close to the right or left eye, on the side of the head receiving the highest dose(10). In cases where leaded glasses were worn, the dosemeters were placed on the outside of the protective shield on the bezel branch. The measured radiation exposure represented the exposure in a normal working schedule of a randomly selected workers over a 3-month period and this cumulative eye lens dose was extrapolated to a 1-year period. Ergonomic assessment Workers wearing the dosemeters were asked to assess the ergonomics of the eye lens dosemeters based on losses, discomfort, difficulties, falls and sterility risks to the surgical field. Each of the three models of dosemeter (Landauer, Dosilab and IRSN) was assessed (Figure 1). The number of workers favourable to wearing the tested dedicated dosemeter was also reported. Statistical analysis Continuous variables were expressed by their means ± standard deviation (SD) or medians and range [min–max]. Categorical variables were expressed as numbers and percentages. RESULTS Population Overall, 87 workers wore the eye lens dosemeter during their normal working schedule (Table 1). Three dosemeters were not assigned. The cardiology IP mainly included coronarographies, removal of material, implementation of pacemakers or defibrillators; that was for radiology endovascular procedures, biopsies, infiltrations and embolization; limb fractures and vertebroplasties for surgery; dilatations, implementation of prostheses and cholangiographies for gastroenterology (Table 1). Dosimetry A total of 64 dosemeters were analysed. The remaining 23 (IRSN = 5, Dosilab = 11, Landauer = 7) were not worn throughout the entire study period due to losses, one sick leave (vascular surgeon), and six dosemeters which were not rendered at the end of the study (vascular surgeons). Details of dosimetry results are summarised in Tables 2 for the 3-month period and Table 3 for the extrapolation to 1 year. The estimated annual eye lens radiation exposure ranges from a minimum of 0.00 mSv to a maximum of 18.12 mSv with an average dose of 0.96 ± 2.28 mSv if the use of leaded glasses is not taken into consideration. The maximal value of 18.12 mSv related to a cardiologist. The lowest average doses concerns gastroenterology 0.22 ± 0.54 mSv while the highest concerns cardiology 4.06 ± 6.19 mSv. Overall, the period studied did not correspond to a heavy workload and no incidental procedure was reported. This period was particularly sparse in terms of radiological interventions for the equine veterinarians and auxiliaries who are known to receive high levels of ionising radiation due to the animals’ high mass. The mean number of IP per 3 months in gastroenterolgy was 8 by worker, 21 for radiology, 24 for cardiology and 12 for surgery. An extrapolation of the present results to a heavier workload level, twice more, lead to a mean dose of 0.44 (max 2.64) mSv for gastroenterology, 1.16 (max 4.64) mSv for radiology, 8.12 (max 36.24) mSv for cardiology, 1.08 (max 8.88) mSv for surgery and 3.14 (max 4.16) mSv for equin veterinarians. Table 2. Results of dosimetry (Hp(3)) according to speciality over a 3-month period. 3 Months Mean ± SD (mSv) Median [min–max] (mSv) Radiology 0.14 ± 0.18 0.09 [0.00–0.58] Cardiology 1.02 ± 1.55 0.38 [0.00–4.53] Surgery 0.13 ± 0.22 0.00 [0.00–1.11] Gastroenterology 0.06 ± 0.13 0.00 [0.00–0.33] Equine veterinarian 0.39 ± 0.09 0.37 [0.25–0.52] Total 0.27 ± 0.60 0.18 [0.00–4.53] Controls, n = 3 0.22 ± 0.19 0.33 [0.00–0.33] 3 Months Mean ± SD (mSv) Median [min–max] (mSv) Radiology 0.14 ± 0.18 0.09 [0.00–0.58] Cardiology 1.02 ± 1.55 0.38 [0.00–4.53] Surgery 0.13 ± 0.22 0.00 [0.00–1.11] Gastroenterology 0.06 ± 0.13 0.00 [0.00–0.33] Equine veterinarian 0.39 ± 0.09 0.37 [0.25–0.52] Total 0.27 ± 0.60 0.18 [0.00–4.53] Controls, n = 3 0.22 ± 0.19 0.33 [0.00–0.33] SD = standard deviation, mSv = millisievert, min = minimale value, max = maximale value, Hp(3) = personal dose equivalent to the eye-lens at a depth of 3 mm. Table 2. Results of dosimetry (Hp(3)) according to speciality over a 3-month period. 3 Months Mean ± SD (mSv) Median [min–max] (mSv) Radiology 0.14 ± 0.18 0.09 [0.00–0.58] Cardiology 1.02 ± 1.55 0.38 [0.00–4.53] Surgery 0.13 ± 0.22 0.00 [0.00–1.11] Gastroenterology 0.06 ± 0.13 0.00 [0.00–0.33] Equine veterinarian 0.39 ± 0.09 0.37 [0.25–0.52] Total 0.27 ± 0.60 0.18 [0.00–4.53] Controls, n = 3 0.22 ± 0.19 0.33 [0.00–0.33] 3 Months Mean ± SD (mSv) Median [min–max] (mSv) Radiology 0.14 ± 0.18 0.09 [0.00–0.58] Cardiology 1.02 ± 1.55 0.38 [0.00–4.53] Surgery 0.13 ± 0.22 0.00 [0.00–1.11] Gastroenterology 0.06 ± 0.13 0.00 [0.00–0.33] Equine veterinarian 0.39 ± 0.09 0.37 [0.25–0.52] Total 0.27 ± 0.60 0.18 [0.00–4.53] Controls, n = 3 0.22 ± 0.19 0.33 [0.00–0.33] SD = standard deviation, mSv = millisievert, min = minimale value, max = maximale value, Hp(3) = personal dose equivalent to the eye-lens at a depth of 3 mm. Table 3. Results of dosimetry (Hp(3)) according to speciality extrapolated over a 1-year period. Extrapolation to 1 year Mean ± SD (mSv) Median [min–max] (mSv) Radiology 0.58 ± 0.72 0.35 [0.00–2.32] Cardiology 4.06 ± 6.19 1.50 [0.00–18.12] Surgery 0.54 ± 0.88 0.00 [0.00–4.44] Gastroenterology 0.22 ± 0.54 0.00 [0.00–1.32] Equine veterinarian 1.57 ± 0.36 1.48 [1.00–2.08] Total 0.96 ± 2.28 0.20 [0.00–18.12] Controls, n = 3 0.87 ± 0.76 1.03 [0.00–1.32] Extrapolation to 1 year Mean ± SD (mSv) Median [min–max] (mSv) Radiology 0.58 ± 0.72 0.35 [0.00–2.32] Cardiology 4.06 ± 6.19 1.50 [0.00–18.12] Surgery 0.54 ± 0.88 0.00 [0.00–4.44] Gastroenterology 0.22 ± 0.54 0.00 [0.00–1.32] Equine veterinarian 1.57 ± 0.36 1.48 [1.00–2.08] Total 0.96 ± 2.28 0.20 [0.00–18.12] Controls, n = 3 0.87 ± 0.76 1.03 [0.00–1.32] SD = standard deviation, mSv = millisievert, min = minimale value, max = maximale value, Hp(3) = personal dose equivalent to the eye-lens at 3 mm depth. Table 3. Results of dosimetry (Hp(3)) according to speciality extrapolated over a 1-year period. Extrapolation to 1 year Mean ± SD (mSv) Median [min–max] (mSv) Radiology 0.58 ± 0.72 0.35 [0.00–2.32] Cardiology 4.06 ± 6.19 1.50 [0.00–18.12] Surgery 0.54 ± 0.88 0.00 [0.00–4.44] Gastroenterology 0.22 ± 0.54 0.00 [0.00–1.32] Equine veterinarian 1.57 ± 0.36 1.48 [1.00–2.08] Total 0.96 ± 2.28 0.20 [0.00–18.12] Controls, n = 3 0.87 ± 0.76 1.03 [0.00–1.32] Extrapolation to 1 year Mean ± SD (mSv) Median [min–max] (mSv) Radiology 0.58 ± 0.72 0.35 [0.00–2.32] Cardiology 4.06 ± 6.19 1.50 [0.00–18.12] Surgery 0.54 ± 0.88 0.00 [0.00–4.44] Gastroenterology 0.22 ± 0.54 0.00 [0.00–1.32] Equine veterinarian 1.57 ± 0.36 1.48 [1.00–2.08] Total 0.96 ± 2.28 0.20 [0.00–18.12] Controls, n = 3 0.87 ± 0.76 1.03 [0.00–1.32] SD = standard deviation, mSv = millisievert, min = minimale value, max = maximale value, Hp(3) = personal dose equivalent to the eye-lens at 3 mm depth. Ergonomics The dosemeter assessed as the least uncomfortable to wear was the IRSN model due to its stability, limiting losses and risks of falling onto the surgical field. It was also rarely forgotten due to its size and fixing type. However, it was considered as being painful to wear at times (Table 4). Overall, 50% of the medical staff estimates that the Landauer dosemeter model fall, also it was judged to present a sterility risk. The Dosilab dosemeter model was considered as uncomfortable in 60% of cases resulting on inconvenient to wear daily. Table 4. Ergonomics assessment of the three dosemeters models tested (Dosilab, Landauer and IRSN). Dosilab Landauer IRSN Number of responses 10 10 18 Forgotten on headband/trash 3 (30%) 4 (40%) 4 (22%) Recover after forgotten 2 (20%) 6 (60%) 3 (17%) Discomforts 6 (60%) 6 (60%) 7 (39%) Difficulties  Falls NR 5 (50%) NR  Sterility risks NR 2 (20%) NR  Forgetfulness 3 (30%) 2 (20%) 1 (5.6%)  Inconvenient 4 (40%) NR 7 (39%) Favourable to wearing 4 (40%) 6 (60%) 13 (72%) Dosilab Landauer IRSN Number of responses 10 10 18 Forgotten on headband/trash 3 (30%) 4 (40%) 4 (22%) Recover after forgotten 2 (20%) 6 (60%) 3 (17%) Discomforts 6 (60%) 6 (60%) 7 (39%) Difficulties  Falls NR 5 (50%) NR  Sterility risks NR 2 (20%) NR  Forgetfulness 3 (30%) 2 (20%) 1 (5.6%)  Inconvenient 4 (40%) NR 7 (39%) Favourable to wearing 4 (40%) 6 (60%) 13 (72%) NR = not reported. Data are expressed as numbers and percentages of subjects. Table 4. Ergonomics assessment of the three dosemeters models tested (Dosilab, Landauer and IRSN). Dosilab Landauer IRSN Number of responses 10 10 18 Forgotten on headband/trash 3 (30%) 4 (40%) 4 (22%) Recover after forgotten 2 (20%) 6 (60%) 3 (17%) Discomforts 6 (60%) 6 (60%) 7 (39%) Difficulties  Falls NR 5 (50%) NR  Sterility risks NR 2 (20%) NR  Forgetfulness 3 (30%) 2 (20%) 1 (5.6%)  Inconvenient 4 (40%) NR 7 (39%) Favourable to wearing 4 (40%) 6 (60%) 13 (72%) Dosilab Landauer IRSN Number of responses 10 10 18 Forgotten on headband/trash 3 (30%) 4 (40%) 4 (22%) Recover after forgotten 2 (20%) 6 (60%) 3 (17%) Discomforts 6 (60%) 6 (60%) 7 (39%) Difficulties  Falls NR 5 (50%) NR  Sterility risks NR 2 (20%) NR  Forgetfulness 3 (30%) 2 (20%) 1 (5.6%)  Inconvenient 4 (40%) NR 7 (39%) Favourable to wearing 4 (40%) 6 (60%) 13 (72%) NR = not reported. Data are expressed as numbers and percentages of subjects. DISCUSSION The eye lens is one of the most radiosensitive tissues of the human body(1); if exposed to ionising radiation it can develop radiation-induced cataract at an early age(2). The dose to the eye lens can be assessed using the dose equivalent Hp(10) measured with a whole-body dosemeter worn above the protective apron near the lead collar(9). However, dedicated dosemeters allow a more accurate estimation of radiation exposure to the eye lens in dose equivalent Hp(3) corresponding to the personal dose equivalent to the eye lens at a depth of 3 mm(10). The present study demonstrates that medical and paramedical workers exposed to ionising radiation in a military hospital during surgery and IP of cardiology, radiology and gastroenterology as well as equine veterinarians and auxiliaries had an estimated annual eye lens dose below the revised ICRP’s limit of 20 mSv/y, with the highest doses for cardiology 4.06 ± 6.19 mSv (maximal value of 18.12 mSv) and lowest for gastroenterology 0.22 ± 0.54 mSv (maximal value of 1.32 mSv). Nonetheless, these results correspond to a normal workload and cannot be extrapolated to those of a heavy workload or those in incident situations. Moreover, considering that protective glasses were used for some workers the estimated dose to the eye lens of the present study could reach or exceed the ICRP’s limit(11, 12). Vaes et al.(13) had prospectively investigated the radiation exposure of 16 anesthesiologists during a routine year of professional activity. The exposure was extrapolated from 1-month cumulative eye lens dose in a normal working schedule including neuro-embolization, radiofrequency ablation, vertebroplasty and kyphoplasty. The estimated annual eye lens doses range from 0.4 to 3.5 mSv with an average dose of 1.3 mSv. The highest maximum and average doses were for neuroembolization, cardiac ablation and vertebra/kyphoplasty procedures(13). In line with the present results, cardiology IP were found to have the highest doses, while radiological IP of the present study, not specifically focused on neuroembolization, demonstrated to have less important mean dose values (0.58 ± 0.72 mSv). Indeed Koukorava et al.(14) during radiological IP found higher dose values for therapeutic procedures, especially embolization. The maximal recorded eye lens dose during a single procedure was 2.4 mSv for brain embolization. The annual doses estimated for the operator with the highest workload according to the measurement was 49.3 mSv to the eye lens(14). In the same way, Urboniene et al.(9) had assessed the eye lens doses of 50 workers during radiology IP. If the use of leaded glasses is not taken into account, the estimated maximum annual dose equivalent to the lens of the eye was 82 mSv for a cardiology procedure(9). These above mentioned studies demonstrate that the annual ICRP’s dose limit can largely be exceeded in the spectrum of cardiology and therapeutic radiology IP particularly for the main operator(9, 14). The conclusion of the 129 cardiologists cohort of the ‘Occupational Cataracts and Lens Opacities in interventional Cardiology’(15) was that after several years of practice, without eye protection, the dose may exceed the new ICRP lifetime eye threshold of 500 mSv. For work over an average period of 22 years, the estimated cumulative eye lens dose ranges from 25 mSv to more than 1600 mSv with a mean of 423 ± 359 mSv. Strengthening the results of the present study, interventional cardiologists are considered by Jacob et al.(15) at high risk of developing early radiation-induced cataracts(15). In the field of surgery, Romanova et al.(16) assessing the radiation dose to the eye lens of orthopaedic surgeons demonstrated that for fractura femoris, from an extrapolation to one procedure value, at a normal workload, the estimated mean annual dose values (10.9 mSv, min 4.7–max 17.7) did not exceed the annual occupational dose limit, while at a heavy workload it could be achieved or exceed (21.7 mSv, min 9.5–max 35.5). They demonstrated also with phantom measurements that the use of half-dose mode could reduce the dose to the eye lens of the operator(16). While not specifically focused on fractura femoris the annual estimated mean dose to the eye lens of surgery procedures in the present study shows clearly lower values (0.54 mSv, min 0.00–max 4.44) at a normal workload as well as at a heavier twice more workload 1.08 (max 8.88) mSv. Recently Suzuki et al.(12) reported a maximum equivalent dose to the eye lens at 0.8 mSv/month during orthopaedic surgery using an C-Arm X-ray system. Moreover, they identified that the leaded glasses reduced exposure by ~60%(12). Consequently if the physicians of the present study wear the leaded glasses, the highest dose of 18.12 mSv should be reduced to 7.20 mSv per year that is very far from the annual dose limit at a normal workload schedule. The results of the present study demonstrate that the maximal estimated annual eye lens radiation exposure can be close to 20 mSv for cardiologists at a normal workload, while for others specialities in particular radiology and surgery as well as equin veterinarians this maximal value is far. Based on these results and those previously published, eye lens dose monitoring of workers during IP appears to be necessary, especially in cardiology and a fortiori in others specialities according to the type of procedure and the workload level considered. Indeed one major limitation of the present study lies on the dose values obtained from a normal workload schedule over a 3-month period that cannot be strictly representative of a 1-year period, which may include a heavier workload or incident situations. Consequently, training workers exposed to ionising radiations is strongly recommended. The use of personal radiation protection equipment is also highly encouraged without additional reinforcement. CONCLUSION At a normal workload level, the estimated annual dose received by the eye lens of workers did not reach the revised ICRP annual dose limit of 20 mSv. At a heavy workload level (twice more) or maybe in incident situations the exposure could exceed this limit, reaching 36.24 mSv for a cardiologist. Monitoring eye lens radiation exposure of workers during IP may be necessary in addition to training about the risks of ionising radiations and the wearing of standard personal radiation protection equipment without additional enhancement. ACKNOWLEDGEMENTS IRSN, Dosilab and Landauer laboratories. The departments of surgery, radiology and cardiology of HIA Percy, the department of gastroenterology of HIA Begin and the equine veterinarians and auxiliaries serving the Republican Guard. M.E.R.C.N. Céline Darve. FUNDING This research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors. We declare no competing interests. REFERENCES 1 Poppe , E. Experimental investigations on cataract formation following whole-body roentgen irradiation . Acta Radiol. 47 ( 2 ), 138 – 148 ( 1957 ). Google Scholar CrossRef Search ADS PubMed 2 Ainsbury , E. A. et al. . Ionizing radiation induced cataracts: recent biological and mechanistic developments and perspectives for future research . Mutat. Res. 770 ( Pt B ), 238 – 261 ( 2016 ). Google Scholar CrossRef Search ADS PubMed 3 Bouffler , S. , Ainsbury , E. , Gilvin , P. and Harrison , J. Radiation-induced cataracts: the Health Protection Agency’s response to the ICRP statement on tissue reactions and recommendation on the dose limit for the eye lens . J. Radiol. Prot. 32 ( 4 ), 479 – 488 ( 2012 ). Google Scholar CrossRef Search ADS PubMed 4 Thrapsanioti , Z. , Askounis , P. , Datseris , I. , Diamanti , R. A. , Papathanasiou , M. and Carinou , E. Eye lens radiation exposure in Greek Interventional Cardiology Article . Radiat. Prot. Dosim. 175 ( 3 ), 344 – 356 ( 2017 ). 5 Matsubara , K. , Lertsuwunseri , V. , Srimahachota , S. , Krisanachinda , A. , Tulvatana , W. , Khambhiphant , B. , Sudchai , W. and Rehani , M. Eye lens dosimetry and the study on radiation cataract in interventional cardiologists . Phys. Med. 44 , 232 – 235 ( 2017 ). Google Scholar CrossRef Search ADS PubMed 6 Authors on behalf of ICRP , Stewart , F. A. , Akleyev , A. V. , Hauer-Jensen , M. , Hendry , J. H. , Kleiman , N. J. , Macvittie , T. J. , Aleman , B. M. , Edgar , A. B. , Mabuchi , K. et al. . ICRP publication 118: ICRP statement on tissue reactions/early and late effects of radiation in normal tissues and organs—threshold doses for tissue reactions in a radiation protection context . Ann. ICRP 41 ( 1–2 ), 1 – 322 ( 2012 ). Google Scholar CrossRef Search ADS PubMed 7 2008, U. Sources and effects of ionizing radiation ( 2010 ). 8 Kim , K. P. , Miller , D. L. , Balter , S. , Kleinerman , R. A. , Linet , M. S. , Kwon , D. and Simon , S. L. Occupational radiation doses to operators performing cardiac catheterization procedures . Health Phys. 94 ( 3 ), 211 – 227 ( 2008 ). Google Scholar CrossRef Search ADS PubMed 9 Urboniene , A. , Sadzeviciene , E. and Ziliukas , J. Assessment of eye lens doses for workers during interventional radiology procedures . Radiat. Prot. Dosim. 165 ( 1–4 ), 299 – 303 ( 2015 ). Google Scholar CrossRef Search ADS 10 Carinou , E. , Ferrari , P. , Bjelac , O. C. , Gingaume , M. , Merce , M. S. and O’Connor , U. Eye lens monitoring for interventional radiology personnel: dosemeters, calibration and practical aspects of Hp(3) monitoring. A 2015 review . J. Radiol. Prot. 35 ( 3 ), R17 – R34 ( 2015 ). Google Scholar CrossRef Search ADS PubMed 11 Hu , P. , Kong , Y. , Chen , B. , Liu , Q. , Zhuo , W. and Liu , H. Shielding effect of lead glasses on radiologists’ eye lens exposure in interventional procedures . Radiat. Prot. Dosim. 174 ( 1 ), 136 – 140 ( 2017 ). 12 Suzuki , A. , Matsubara , K. and Sasa , Y. Measurement of radiation doses to the eye lens during orthopedic surgery using an C-arm X-ray system . Radiat. Prot. Dosim. 1 – 7 ( 2017 ). doi: 10.1093/rpd/ncx250. 13 Vaes , B. , Van Keer , K. , Struelens , L. , Schoonjans , W. , Nijs , I. , Vandevenne , J. and Van Poucke , S. Eye lens dosimetry in anesthesiology: a prospective study . J. Clin. Monit. Comput. 31 ( 2 ), 303 – 308 ( 2017 ). Google Scholar CrossRef Search ADS PubMed 14 Koukorava , C. , Carinou , E. , Simantirakis , G. , Vrachliotis , T. G. , Archontakis , E. , Tierris , C. and Dimitriou , P. Doses to operators during interventional radiology procedures: focus on eye lens and extremity dosimetry . Radiat. Prot. Dosim. 144 ( 1–4 ), 482 – 486 ( 2011 ). Google Scholar CrossRef Search ADS 15 Jacob , S. , Donadille , L. , Maccia , C. , Bar , O. , Boveda , S. , Laurier , D. and Bernier , M. O. Eye lens radiation exposure to interventional cardiologists: a retrospective assessment of cumulative doses . Radiat. Prot. Dosim. 153 ( 3 ), 282 – 293 ( 2013 ). Google Scholar CrossRef Search ADS 16 Romanova , K. , Vassileva , J. and Alyakov , M. Radiation exposure to the eye lens of orthopaedic surgeons during various orthopaedic procedures . Radiat. Prot. Dosim. 165 ( 1–4 ), 310 – 313 ( 2015 ). Google Scholar CrossRef Search ADS © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/about_us/legal/notices)

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Radiation Protection DosimetryOxford University Press

Published: May 4, 2018

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