Eye & brain dose
2023
Evaluation of Lens Doses among Medical Staff Involved in Nuclear Medicine: Current Eye Radiation Exposure among Nuclear-Medicine Staff
Abstract: The International Commission on Radiological Protection has lowered the annual equivalent eye-lens dose to 20 mSv. Although occupational exposure can be high in nuclear medicine (NM) departments, few studies have been conducted regarding eye-lens exposure among NM staff.
This study aimed to estimate the annual lens doses of staff in an NM department and identify factors
contributing to lens exposure.
Four nurses and six radiographers performing positron emission tomography (PET) examinations and four radiographers performing radioisotope (RI) examinations (excluding PET) were recruited for this study. A lens dosimeter was attached near the left eye to measure the 3-mm-dose equivalent; a personal dosimeter was attached to the left side of the neck to measure the 1-cm- and 70-µm-dose equivalents. Measurements were acquired over six months, and the cumulative lens dose was doubled to derive the annual dose.
Correlations between the lens and personal-dosimeter doses, between the lens dose and the numbers of procedures, and between the lens dose and the amounts of PET drugs (radiopharmaceuticals) injected were examined.
Wilcoxon’s signed-rank test was used to compare lens and personal-dosimeter doses. The estimated
annual doses were 0.93 ± 0.13 mSv for PET nurses, 0.71 ± 0.41 mSv for PET radiographers, and
1.10 ± 0.53 mSv for RI radiographers.
For PET nurses, but not for PET or RI radiographers, there was a positive correlation between the numbers of procedures and lens doses and between amounts injected and lens doses. There was a significant difference between the lens and personal-dosimeter doses of PET nurses.
The use of protective measures, such as shielding, should prevent NM staff from receiving lens doses > 20 mSv/year. However, depending on the height of the protective shield, PET nurses may be unable to assess the lens dose accurately using personal dosimeters.
Keywords: radiation protection and safety; nuclear medicine; positron emission tomography (PET);
radioisotope (RI) examination; single-photon emission computed tomography (SPECT); eye-lens
dose; nurse; occupational radiation exposure; radiographer; disaster medicine
Fujisawa M, Haga Y, Sota M, et al. Evaluation of Lens Doses among Medical Staff Involved in Nuclear Medicine: Current Eye Radiation Exposure among Nuclear-Medicine Staff. Applied sciences. 2023; 13: 9182.
Occupational radiation exposure of neurointerventionalists during endovascular stroke treatment
Background
Radiological neuro-interventions, especially endovascular stroke treatment (EST), are increasing in case numbers worldwide with increasing occupational radiation exposure. Aim of this study was to define the radiation exposure of neurointerventionalists (NI) during EST and to compare the accumulated dose reaching the left arm with the left temple.
Methods
This is a prospective observational study in a tertiary stroke center conducted between 11/2021 and 07/2022. Radiation exposure was measured using real time dosimetry with dosimeters being carried by the NI during EST simultaneously at the left temple and left arm. The effective dose [µSV] per dose area product (DAP) and potential influencing factors were compared in univariate analysis between the two dosimeter positions.
Results
In total, 82 ESTs were analyzed with a median DAP of 6179 µGy*m2 (IQR 3271 µGy*m2–11720 µGy*m2). The accumulated dose at the left arm and left temple correlated with the DAP and fluoroscopy time of the EST (DAP and arm: p = 0.01, DAP and temple: p = 0.006). The radiation exposure (RE) showed a wide range and did not differ between the two dosimeter positions (median, IQR arm 7 µSV, IQR 3.1–16.9 µSV, min. 0.3 µSV max. 64.5 µSV) vs. head 7 µSv, IQR 3.2–17.4 µSV, min. 0.38 µSV, max. 48.6 µSV, p = 0.94). Occupational RE depends on the number of thrombectomy attempts, but not the target vessel occlusion location or the NI’s body height.
Conclusion
Neurointerventionalists experience a generally low but very variable radiation exposure during EST, which depends on the intervention’s fluoroscopy time and dose area product as well as thrombectomy attempts but does not differ between left temple and left arm.
Weyland CS, Jesser J, Bourgart I, et al. Occupational radiation exposure of neurointerventionalists during endovascular stroke treatment. Eur J Radiol. 2023; 164: 110882.
Operator Intracranial Dose Protection During Fluoroscopic-Guided Interventions
Purpose: We utilized an anthropomorphic model made with a human skull to determine how different personal protective equipment influence operator intracranial radiation absorbed dose.
Materials and methods: A custom anthropomorphic phantom made with a human skull coated with polyurethane rubber, mimicking superficial tissues, and was mounted onto a plastic thorax. To simulate scatter, an acrylic plastic scatter phantom was placed onto the fluoroscopic table with a 1.5 mm lead apron on top. Two Radcal radiation detectors were utilized; one inside of the skull and a second outside. Fluoroscopic exposures were performed with and without radiation protective equipment in AP, 45-degree RAO, and 45-degree LAO projections.
Results: The skull and soft tissues reduce intracranial radiation by 76% when compared to radiation outside the skull. LAO (308.95 μSv/min) and RAO projections (96.47μSv/min) result in significantly higher radiation exposure to the primary operator when compared to an AP projection (54 μSv/min). All tested radiation protection equipment demonstrated various reduction in intracranial radiation when compared to no protection. The hood (68% reduction in AP, 91% LAO, and 43% in RAO), full cover (53% reduction in AP, 76% in LAO, and 54% in RAO), and open top with ear coverage (43% reduction in AP, 77% reduction in LAO, and 22% in RAO) demonstrated the most reduction in intracranial radiation when compared to the control.
Conclusion: All tested equipment provided various degrees of additional intracranial protection. The skull and soft tissues attenuate a portion of intracranial radiation.
Keywords: Intracranial radiation protection; Lead cap; Lead glasses; Personal protective equipment; Radiation protective equipment; Thyroid collar.
Qazi E, Ursani A, Patel N, et al. Operator Intracranial Dose Protection During Fluoroscopic-Guided Interventions. Cardiovasc Intervent Radiol. 2023; 46: 943-52.
Evaluation of operator eye exposure and eye protective devices in interventional radiology: Results on clinical staff and phantom
Purpose
To assess occupational eye lens dose based on clinical monitoring of interventional radiologists and to assess personal protective eyewear (PPE) efficacy through measurements with anthropomorphic phantom.
Methods
Two positions of the operator with respect to X-ray beam were simulated with phantom. Dose reduction factor (DRF) of four PPE was assessed, as well as correlation between eye lens and whole-body doses. Brain dose was also assessed. Five radiologists were monitored for one-year clinical procedures. All subjects were equipped with whole-body dosimeter placed over lead apron at the chest level and eye lens dosimeter placed over the left side of the PPE. Kerma-Area Product (KAP) of procedures performed during the monitoring period was recorded. The correlation of eye lens dose with whole-body dose and KAP was assessed.
Results
DRF was 4.3/2.4 for wraparound glasses, 4.8/1.9 for fitover glasses, 9.1/6.8 for full-face visor in radial/femoral geometries. DRF of half-face visor depended on how it is worn (range 1.0–4.9). Statistically significant correlation between dose value over the PPE and chest dose was observed, while there was no correlation between eye lens dose and chest dose. The results on clinical staff showed statistically significant correlation between dose values over the PPE and KAP.
Conclusions
All PPE showed significant DRF in all configurations, provided they were worn correctly. Single DRF value is not applicable to all clinical situations. KAP is a valuable tool for determining appropriate radiation protection measures.
D’Alessio A, Matheoud R, Cannillo B, et al. Evaluation of operator eye exposure and eye protective devices in interventional radiology: Results on clinical staff and phantom. Phys Med. 2023; 110: 102603.
2022
Disposable, lightweight shield decreases operator eye and brain radiation dose when attached to safety eyewear during fluoroscopically guided interventions
Objective
Long-term radiation exposure from fluoroscopically guided interventions (FGIs) can cause cataracts and brain tumors in the operator. We have previously demonstrated that leaded eyewear does not decrease the operator eye radiation dose unless lead shielding has been added to the lateral and inferior portions. Therefore, we have developed a disposable, lightweight, lead-equivalent shield that can be attached to the operator’s eyewear that conforms to the face and adheres to the surgical mask. In the present study, we evaluated the efficacy of our new prototype in lowering the operator brain and eye radiation dose when added to both leaded and nonleaded eyewear.
Methods
The attenuating efficacy of leaded eyewear alone, leaded eyewear plus the prototype, and nonleaded eyewear plus the prototype were compared with no eyewear protection in both a simulated setting and clinical practice. In the simulation, optically stimulated, luminescent nanoDot detectors (Landauer, Inc, Glenwood, Ill) were placed inside the ocular, temporal lobe, and midbrain spaces of a head phantom (ATOM model-701; CIRS, Norfolk, Va). The phantom was positioned to represent a primary operator performing right femoral access. Fluorography was performed on a plastic scatter phantom at 80 kVp for an exposure of 3 Gy reference air kerma. In the clinical setting, nanoDots were placed below the operator’s eye both inside and outside the prototype during the FGIs. The median and interquartile ranges were calculated for the dose at each nanoDot location for the phantom and clinical studies. The average dose reduction was also recorded.
Results
Wearing standard leaded eyewear alone did not decrease the operator ocular or brain radiation dose. In the phantom experiment, the leaded glasses plus the prototype reduced the radiation dose to the lens, temporal lobe, and midbrain by 83% (P < .001), 78% (P < .001), and 75% (P < .001), respectively. The nonleaded glasses plus the prototype also reduced the dose to the lens, temporal lobe, and midbrain by 85% (P < .001), 81% (P < .001), and 71% (P < .001), respectively. A total of 15 FGIs were included in the clinical setting, with a median reference air kerma of 98.4 mGy. The use of our prototype led to an average operator eye dose reduction of 89% (P < .001).
Conclusions
Attaching our prototype to both leaded and nonleaded glasses significantly decreased the eye and brain radiation dose to the operator. This face shield attachment provided meaningful radiation protection and should be considered as either a replacement or an adjunct to routine eyewear.
Kirkwood ML, Klein A, Timaran C, et al. Disposable, lightweight shield decreases operator eye and brain radiation dose when attached to safety eyewear during fluoroscopically guided interventions. J Vasc Surg. 2022; 75: 2047-53.
Surgeon eye lens dose monitoring in interventional neuroradiology, cardiovascular and radiology procedures
Purpose
This study investigated the radiation dose to surgeon eye lens for single procedure and normalised to exposure parameters for eight selected neuroradiology, cardiovascular and radiology interventional procedures.
Methods
The procedures investigated were diagnostic study, Arteriovenous Malformations treatment (AVM) and aneurysm embolization for neuroradiology procedures, Coronary Angiography and Percutaneous Transluminal Coronary Angioplasty (CA-PTCA), Pacemaker and Implantable Cardioverter-Defibrillator implantation (PM-ICD), Endovascular Aortic Repair (EVAR) and Fenestrated Endovascular Aortic Repair (FEVAR) for cardiovascular and electrophysiology procedures. CT-guided lung biopsy was also monitored.
All procedures were performed with table-mounted and ceiling-suspended shields (0.5 mm lead equivalent thickness), except for FEVAR and PM-ICD where only a table mounted shield was present, and CT-guided lung biopsy where no shield was used. Dose assessment was performed using a dosemeter positioned close to the most exposed eye of the surgeon, outside the protective eyewear.
Results
The surgeon most exposed eye lens median Hp(3) equivalent dose for a single procedure, without protective eyewear contribution, was 18 μSv for neuroradiology diagnostic study, 62 μSv for AVM, 38 μSv for aneurysm embolization, 33 μSv for CA-PTCA, 39 μSv for PM-ICD, 49 μSv for EVAR, 2500 μSv for FEVAR, 153 μSv for CT-guided lung biopsy.
Conclusions
In interventional procedures, the 20 mSv/year dose limit for surgeon eye lens exposure might be exceeded if shields or protective eyewear are not used.
Surgeon eye lens doses, normalised to single procedures and to exposure parameters, are a valuable tool for determining appropriate radiation protection measures and dedicated eye lens dosemeter assignment.
Busoni S, Bruzzi M, Giomi S, et al. Surgeon eye lens dose monitoring in interventional neuroradiology, cardiovascular and radiology procedures. Phys Med. 2022; 104: 123-8.
The eye lens dose of the interventionalist: Measurement in practice
Objective
Early 2018, the new eye lens dose limit of 20 mSv per year for occupational exposure to ionising radiation was implemented in the European Union. Dutch guidelines state that monitoring is compulsory above an expected eye lens dose of 15 mSv/year. In this study we propose a method to investigate whether the eye lens dose of interventionalists would exceed 15 mSv/year and to determine if the eye lens dose can be derived from the regular personal dosimeter measurements.
Methods
The eye lens dose, Hp(3), of interventional radiologists (n = 2), cardiologists (n = 2) and vascular surgeons (n = 3) in the Máxima Medical Centre, The Netherlands, was measured during six months, using thermoluminescence dosimeters on the forehead. Simultaneously, the surface dose, Hp(0,07), and whole body dose, Hp(10), were measured using regular dosimeters outside the lead skirt at chest level. The dosimeters were simultaneously refreshed every four weeks. The eye lens dose was compared to both the body-worn dosimeter values. Measurements were performed in the angiography suite, Cath lab and hybrid OR.
Results
A clear relation was observed between the two dosimeters: Hp(3) ≈ 0,25 Hp(0,07). The extrapolated year dose for the eye lens did not exceed 15 mSv for any of the interventionalists (average 3 to 10 studies/month).
Conclusions
The eye lens dose can be monitored indirectly through the regular dosimeter at chest level. Additionally, based on the measurements we conclude that all monitored interventionalists remain below the dose limit and compulsory monitoring limit for the eye lens dose.
Keywords
Meijer EJ, van Zandvoort DWH, Loos MJA, Tseng CMESN and van Pul C. The eye lens dose of the interventionalist: Measurement in practice. Phys Med. 2022; 100: 1-5.
Protected and Unprotected Radiation Exposure to the Eye Lens During Endovascular Procedures in Hybrid Operating Rooms
Objective
Radiation cataract has been observed at lower doses than previously thought, therefore the annual limit for equivalent dose to the eye lens has been reduced from 150 to 20 mSv. This study evaluated radiation exposure to the eye lens of operators working in a hybrid operating room before and after implementation of a dose reduction program.
Methods
From April to October 2019, radiation exposure to the first operator was measured during all consecutive endovascular procedures performed in the hybrid operating room using BeOSL Hp(3) eye lens dosimeters placed both outside and behind the lead glasses (0.75 mm lead equivalent). Measured values were compared with data from a historic control group from the same hospital before implementation of the dose reduction program.
Results
A total of 181 consecutive patients underwent an endovascular procedure in the hybrid operating room. The median unprotected eye lens dose (outside lead glasses) of the main operator was 0.049 mSv for endovascular aortic repair (EVAR) (n = 30), 0.042 mSv for thoracic endovascular aortic repair (TEVAR) (n = 23), 0.175 mSv for complex aortic fenestrated or branched endovascular procedures (F/BEVAR; n = 15), and 0.042 mSv for peripheral interventions (n = 80). Compared with the control period, EVAR had 75% lower, TEVAR 79% lower, and F/BEVAR 55% lower radiation exposure to the unprotected eye lens of the first operator. The lead glasses led to a median reduction in the exposure to the eye lens by a factor of 3.4.
Conclusion
The implementation of a dose reduction program led to a relevant reduction in radiation exposure to the head and eye lens of the first operator in endovascular procedures. With optimum radiation protection measures, including a ceiling mounted shield and lead glasses, more than 440 EVARs, 280 TEVARs, or 128 FEVARs could be performed per year before the dose limit for the eye lens of 20 mSv was reached.
Jungi S, Ante M, Geisbüsch P, Hoedlmoser H, Kleinau P and Böckler D. Protected and Unprotected Radiation Exposure to the Eye Lens During Endovascular Procedures in Hybrid Operating Rooms. Eur J Vasc Endovasc Surg. 2022; 64: 567-72.
Staff eye lens dose in interventional radiology and cardiology in Finland
Highlights
- For most Finnish interventionalists, eye lens doses are below legal limits.
- A small number of interventionalists may exceed the legal limits for eye lens dose.
- Nurses and radiographers are less exposed than interventionalists.
- For the majority of interventional workers, eye dosemeters are not required.
Purpose
The aim of this study was to investigate the eye lens and whole-body radiation doses to interventional radiology and cardiology staff in two Finnish hospitals.
Methods
Simultaneous measurements of personal dose equivalent quantities Hp(3) and Hp(10) were conducted in clinical conditions during different radiological and cardiological interventional procedures. In order to study the feasibility to estimate eye lens dose with Hp(10) measured over the protective apron or thyroid shield, the ratio between measured Hp(3) and Hp(10) was investigated.
Results and conclusions
Applying the obtained ratio on Hp(10) records from national dose register showed that only a small number of interventional radiologists and cardiologists in Finland may exceed eye lens equivalent dose levels of 20 mSv per year or 100 mSv in five consecutive years, but likely do not exceed 50 mSv in a single year. For the most Finnish interventionalists, the eye lens dose is well below 10 mSv per year. Nurses and radiographers assisting in interventions are, on average, less exposed than interventionalists, and will not exceed 20 mSv per year. Based on our results, Hp(10) measured over the protective apron or thyroid shield provides a conservative estimate of the eye lens dose for interventional radiologists and cardiologists, provided that appropriate protective glasses are used.
Pekkarinen A, Lindholm C, Kortesniemi M and Siiskonen T. Staff eye lens dose in interventional radiology and cardiology in Finland. Phys Med. 2022; 98: 1-7.
2021
Fluoroscopy-guided intervention procedure norms for occupational eye radiation dose: An overall evaluation
Background – Fluoroscopically guided interventional procedures (FGI) are performed with increasing frequency in operating theatre for a growing number of procedures.
Aim – The main objective of radiation management in interventional radiology is to minimise the unnecessary use of radiation.
Methods – In this view, we evaluate the occupational eye dose of an interventional radiologist (IR) for different dosimeter positions commonly utilised in the FGI procedures. Herein, one IR was examined for a period of three months while performing the 65 FGI procedures of different types. Eye doses of the IR were measured using the optically-stimulated luminescence dosimeters called the nanoDots (Landauer, Inc.). The IR wore the protective lead glasses equipped with the nanoDots (on the left and right eye) during the observations period. All the nanoDot measurements were conducted using the microStar reader system (Landauer Inc.).
Results – The eye dose of the IR per dose area product (DAP) was discerned to be 0.85 ± 0.13 μSv.Gy−1.cm−2 for the left eye with the protection. The estimated annual eye dose of 18.32 mSv.y−1 was below the recommended dose limit (20 mSv.y−1). The mean eye dose and DAP correlation was observed to be significant and insignificantly related to the fluoroscopy time (p < 0.05). The observed lower dose for the right eye than that of the left one was attributed to the specific position of the IR with respect to the patient.
Conclusion – Present strategy on the occupational eye dose measurement was shown to be effective for determining the risk of the eye lens dose level in the absence of the protective lead glasses. It is established that the eye dose limit can easily exceed the recommended standard if the IR does not use the protective lead glasses with other safety equipment during the treatment.
Bohari A, Hashim S, Ahmad NE, Ghoshal SK and Mohd Mustafa SN. Fluoroscopy-guided intervention procedure norms for occupational eye radiation dose: An overall evaluation. Radiation physics and chemistry (Oxford, England : 1993). 2021; 178: 108909.
Occupational Radiation Dose to Eye Lenses in CT-Guided Interventions Using MDCT-Fluoroscopy
Abstract: In computed tomography (CT)-guided interventions (CTIs), physicians are close to a
source of scattered radiation. The physician and staff are at high risk of radiation-induced injury
(cataracts). Thus, dose-reducing measures for physicians are important. However, few previous
reports have examined radiation doses to physicians in CTIs.
This study evaluated the radiation dose to the physician and medical staff using multi-detector (MD)CT-fluoroscopy and attempted to understand radiation protection and -reduction methods. The procedures were performed using an interventional radiology (IVR)-CT system.
We measured the occupational radiation dose (physician and nurse) using a personal dosimeter in real-time, gathered CT-related parameters (fluoroscopy time, mAs, CT dose index (CTDI), and dose length product (DLP)), and performed consecutive 232 procedures in CT-guided biopsy. Physician doses (eye lens, neck, and hand; µSv, average ± SD) in our CTIs were 39.1 ± 36.3, 23.1 ± 23.7, and 28.6 ± 31.0, respectively. Nurse doses (neck and chest) were lower (2.3 ± 5.0 and 2.4 ± 4.4, respectively) than the physician doses.
There were significant correlations between the physician doses (eye and neck) and related factors, such as CTfluoroscopy mAs (eye dose: r = 0.90 and neck dose: r = 0.83). We need to understand the importance of reducing/optimizing the dose to the physician and medical staff in CTIs. Our study suggests that physician and staff doses were not significant when the procedures were performed with the appropriate radiation protection and low-dose techniques.
Keywords: CT-guided interventions; eye lens; occupational radiation dose; radiation protection;
scattered radiation
Inaba Y, Hitachi S, Watanuki M and Chida K. Occupational Radiation Dose to Eye Lenses in CT-Guided Interventions Using MDCT-Fluoroscopy. Diagnostics (Basel). 2021; 11: 646.
Eye protection in interventional procedures
Data suggest that radiation-induced cataracts may form without a threshold and at low-radiation doses. Staff involved in interventional radiology and cardiology fluoroscopy-guided procedures have the potential to be exposed to radiation levels that may lead to eye lens injury and the occurrence of opacifications have been reported. Estimates of lens dose for various fluoroscopy procedures and predicted annual dosages have been provided in numerous publications. Available tools for eye lens radiation protection include accessory shields, drapes and glasses. While some tools are valuable, others provide limited protection to the eye. Reducing patient radiation dose will also reduce occupational exposure.
Significant variability in reported dose measurements indicates dose levels are highly dependent on individual actions and exposure reduction is possible.
Further follow-up studies of staff lens opacification are recommended along with eye lens dose measurements under current clinical practice conditions.
Schueler BA and Fetterly KA. Eye protection in interventional procedures. Br J Radiol. 2021; 94: 20210436.
Fluoroscopy-guided intervention procedure norms for occupational eye radiation dose: An overall evaluation
Abstract
The main objective of radiation management in interventional radiology is to minimise the unnecessary use of radiation. Fluoroscopically guided interventional procedures (FGI) are performed with increasing frequency in operating theatre for a growing number of procedures.
In this view, we evaluate the occupational eye dose of an interventional radiologist (IR) for different dosimeter positions commonly utilised in the FGI procedures. Herein, one IR was examined for a period of three months while performing the 65 FGI procedures of different types. Eye doses of the IR were measured using the optically-stimulated luminescence dosimeters called the nanoDots (Landauer, Inc.). The IR wore the protective lead glasses equipped with the nanoDots (on the left and right eye) during the observations period. All the nanoDot measurements were conducted using the microStar reader system (Landauer Inc.).
The eye dose of the IR per dose area product (DAP) was discerned to be 0.85 ± 0.13 μSv.Gy−1.cm−2 for the left eye with the protection. The estimated annual eye dose of 18.32 mSv.y−1 was below the recommended dose limit (20 mSv.y−1). The mean eye dose and DAP correlation was observed to be significant and insignificantly related to the fluoroscopy time (p < 0.05). The observed lower dose for the right eye than that of the left one was attributed to the specific position of the IR with respect to the patient.
Present strategy on the occupational eye dose measurement was shown to be effective for determining the risk of the eye lens dose level in the absence of the protective lead glasses. It is established that the eye dose limit can easily exceed the recommended standard if the IR does not use the protective lead glasses with other safety equipment during the treatment.
Bohari A, Hashim S, Ahmad NE, Ghoshal SK and Mohd Mustafa SN. Fluoroscopy-guided intervention procedure norms for occupational eye radiation dose: An overall evaluation. Radiation Physics and Chemistry. 2021; 178: 108909.
2020
Occupational Doses to Medical Staff Performing or Assisting with Fluoroscopically Guided Interventional Procedures
Background: Staff who perform fluoroscopically guided interventional (FGI) procedures are among the most highly radiation-exposed groups in medicine. However, there are limited data on monthly or annual doses (or dose trends over time) for these workers.
Purpose: To summarize occupational badge doses (lens dose equivalent and effective dose equivalent values) for medical staff performing or assisting with FGI procedures in 3 recent years after accounting for uninformative values and one- versus two-badge monitoring protocol.
Materials and Methods: Badge dose entries of medical workers believed to have performed or assisted with FGI procedures were retrospectively collected from the largest dosimetry provider in the United States for 49991, 81561, and 125 669 medical staff corresponding to years 2009, 2012, and 2015, respectively. Entries judged to be uninformative of occupational doses to FGI procedures staff were excluded. Monthly and annual occupational doses were described using summary statistics.
Results: After exclusions, 22.2% (153 033 of 687 912) of the two- and 32.9% (450173 of 1 366736) of the one-badge entries were judged to be informative. There were 335 225 and 916563 of the two- and one-badge entries excluded, respectively, with minimal readings in the above-apron badge. Among the two-badge entries, 123 595 were incomplete and 76059 had readings indicating incorrect wear of the badges. From 2009 to 2015 there was no change in lens dose equivalent values among workers who wore one badge (P = .96) or those who wore two badges (P = .23). Annual lens dose equivalents for workers wearing one badge (median, 6.9 mSv; interquartile range, 3.8213.8 mSv; n = 6218) were similar to those of staff wearing two badges (median, 7.1 mSv; interquartile range, 4.6211.2 mSv; n = 1449) (P = .18), suggesting a similar radiation environment.
Conclusion: These workers are among the highest exposed to elevated levels of ionizing radiation, although their occupational doses are within U.S. regulatory limits. This is a population that requires consistent and accurate dose monitoring; however, failure to return one or both badges, reversal of badges, and improper badge placement are a major hindrance to this goal.
Borrego D, Kitahara CM, Balter S and Yoder C. Occupational Doses to Medical Staff Performing or Assisting with Fluoroscopically Guided Interventional Procedures. Radiology. 2020; 294: 353.
Estimating brain radiation dose to the main operator in interventional radiology
Aim – The aim of this study was to estimate brain radiation dose to the main operator during interventional radiology procedures.
Methods – Occupational brain doses from 19 interventional procedures were measured using thermoluminiscent dosimeters and an anthropomorphic RANDO woman phantom simulating a main operator.
Results – Results show that interventional radiologists may receive minimum and maximum brain doses per procedure of 0.01 mGy (left temporal cortex) and 0.08 mGy (temporal lobe cortex), respectively.
Conclusion – A radiologist who works without movable shielding devices during procedures and has a typical workload (for example 500 procedures per year), which might exceed the new dose threshold of 0.5 Gy for circulatory disease in the brain working 12.6 years of his career.
Garzón WJ, Andrade G, De Barros VSM, Ribeiro LT and Khoury HJ. Estimating brain radiation dose to the main operator in interventional radiology. J Radiol Prot. 2020; 40: 1170-7.
Correlation between eye lens doses and over apron doses in interventional procedures
Measurements of eye lens dose using over apron dosimeters with a geometric correction factor is an international accepted practice. However, further knowledge regarding geometric correction factors in different contexts is required.
The authors studied the correlation between eye lens dose and over apron dosimetry for different medical specialties in eleven hospitals, using a standardized protocol, two independent over apron dosimeters (worn at chest and at neck levels) and a dedicated calibration procedure.
The results show good correlation between subjects working on the same medical specialty for 5 specialties: Interventional Radiology, Vascular Surgery, Vascular Radiology, Hemodynamics and Neuroradiology.
The geometric correction factors resulting from this study could be used to estimate eye lens dose using over apron dosimeters, which are more comfortable than eye lens dosimeters, as reported by the study subjects, as long as the increased uncertainty of the over apron dosimetry compared to the dedicated eye lens dosimetry is acceptable.
Gracia-Ochoa M, Candela-Juan C, Vilar-Palop J, et al. Correlation between eye lens doses and over apron doses in interventional procedures. Phys Med. 2020; 77: 10-7.
2019
Prevalence of Lens Opacity in Interventional Cardiologists and Professional Working in the Hemodynamics in Brazil
Background – Posterior subcapsular cataract is a tissue reaction commonly found among professionals exposed to ionizing radiation.
Objective – To assess the prevalence of cataract in professionals working in hemodynamics in Brazil.
Methods – Professionals exposed to ionizing radiation (group 1, G1) underwent slit lamp examination with a biomicroscope for lens examination and compared with non-exposed subjects (group 2, G2). Ophthalmologic findings were described and classified by opacity degree and localization using the Lens Opacities Classification System III. Both groups answered a questionnaire on work and health conditions to investigate the presence of risk factors for cataract. The level of significance was set at 5% (p < 0.05).
Results – A total of 112 volunteers of G1, mean age of 44.95 (±10.23) years, and 88 volunteers of G2, mean age of 48.07 (±12.18) years were evaluated; 75.2% of G1 and 85.2% of G2 were physicians. Statistical analysis between G1 and G2 showed a prevalence of posterior subcapsular cataract of 13% and 2% in G1 and G2, respectively (0.0081). Considering physicians only, 38% of G1 and 15% of G2 had cataract, with the prevalence of posterior subcapsular cataract of 13% and 3%, respectively (p = 0.0176). Among non-physicians, no difference was found in the prevalence of cataract (by types).
Conclusions – Cataract was more prevalent in professionals exposed to ionizing radiation, with posterior subcapsular cataract the most frequent finding.
Barbosa, A., Medeiros, R., Corpa, A., Higa, F., Souza, M., Barbosa, P., … Cantarelli, M. (2019). Prevalence of Lens Opacity in Interventional Cardiologists and Professional Working in the Hemodynamics in Brazil. Arquivos Brasileiros de Cardiologia, 112(4), 392–399. https://doi.org/10.5935/abc.20190028
The use of in vitro transcriptional data to identify thresholds of effects in a human lens epithelial cell-line exposed to ionizing radiation
Purpose – The International Commission on Radiological Protection (ICRP) recently recommended reducing the occupational equivalent dose limit for the lens of the eye. Based primarily on a review of epidemiological data, the absorbed dose threshold is now considered to be 0.5 Gy independent of dose-rate and severity of opacification, reduced from the previous threshold of 2 Gy. However, direct mechanistic evidence to support an understanding of the underlying molecular mechanisms of damage is still lacking. To this end, we explored the effects of a broad dose-range of ionizing radiation exposure on gene expression changes in a human lens epithelial (HLE) cell-line in order to better understand the shape of the dose–response relationship and identify transcriptional thresholds of effects.
Methods – HLE cells were exposed to doses of 0, 0.01, 0.05, 0.25, 0.5, 2, and 5 Gy of X-ray radiation at two dose rates (1.62 cGy/min and 38.2 cGy/min). Cell culture lysates were collected 20 h post-exposure and analyzed using whole-genome RNA-sequencing. Pathways and dose-thresholds of biological effects were identified using benchmark dose (BMD) modeling.
Results – Transcriptional responses were minimal at doses less than 2 Gy. At higher doses, there were a significant number of differentially expressed genes (DEGs) (p≤.05, fold change≥|1.5|) at both dose rates, with 1308 DEGs for the low dose rate (LDR) and 840 DEGs for the high dose rate (HDR) exposure. Dose–response modeling showed that a number of genes exhibited non-linear bi-phasic responses, which was verified by digital droplet PCR. BMD analysis showed the majority of the pathways responded at BMD median values in the dose range of 1.5–2.5 Gy, with the lowest BMD median value being 0.6 Gy for the HDR exposure. The minimum pathway BMD median value for LDR exposure, however, was 2.5 Gy. Although the LDR and HDR exposures shared pathways involved in extracellular matrix reorganization and collagen production with BMD median value of 2.9 Gy, HDR exposures were more effective in activating pathways associated with DNA damage response, apoptosis, and cell cycling relative to LDR exposure.
Conclusions – Overall, the results suggest that radiation induces complex non-linear transcriptional dose–response relationships that are dose-rate dependent. Pathways shared between the two dose rates may be important contributors to radiation-induced cataractogenesis. BMD analysis suggests that the majority of pathways are activated above 0.6 Gy, which supports current ICRP identified dose thresholds for deterministic effects to the lens of the eye of 0.5 Gy.
Chauhan, V., Rowan-Carroll, A., Gagné, R., Kuo, B., Williams, A., & Yauk, C. (2019). The use of in vitro transcriptional data to identify thresholds of effects in a human lens epithelial cell-line exposed to ionizing radiation. International Journal of Radiation Biology, 95(2), 156–169. https://doi.org/10.1080/09553002.2019.1539883
New eye lens dosemeters for integration in radiation protection glasses
Highlights
- A new type of RP glasses with 0.5 mm lead equivalent protection is introduced.
- A BeOSL eye lens dosemeter for photon radiation is characterized.
- A TLD eye lens dosemeter for photon and beta radiation is introduced.
- Dosemeters are integrated in the frame of the glasses behind the lead shielding.
A standardized mechanical interface between dosemeter and RP glasses was introduced.
With the annual dose limit for the lens of the eye being lowered to 20 mSv from 2019, both new efforts to improve radiation protection for this part of the body and new approved dosemeters for official dose monitoring are required. The individual monitoring services at the Helmholtz Zentrum München and Dosilab AG, together with MAVIG, have developed a mechanical interface to integrate eye lens dosemeters into radiation protection glasses. MAVIG has designed a new type of radiation protection glasses featuring this dosemeter interface. The two individual monitoring services have independently developed two new types of eye lens dosemeters for the interface. The Munich solution for the eye lens dosemeter is a BeOSL dosemeter for photon radiation with a new detector element introduced by Dosimetrics GmbH in 2018. The Dosilab approach is based on a TLD dosemeter for photon and beta radiation. This work describes the concepts for radiation protection glasses and interface, the new dosemeters, and presents the performance characteristics of the dosemeters in accordance with IEC requirements.
Hoedlmoser, H., Greiter, M., Bandalo, V., Mende, E., Brönner, J., Kleinau, P., … Figel, M. (2019). New eye lens dosemeters for integration in radiation protection glasses. Radiation Measurements, 125, 106–115. https://doi.org/10.1016/j.radmeas.2019.05.002
Cataractogenic load – A concept to study the contribution of ionizing radiation to accelerated aging in the eye lens
Ionizing radiation (IR) damages DNA and other macromolecules, including proteins and lipids. Most cell typescan repair DNA damage and cycle continuously their macromolecules as a mechanism to remove defectiveproteins and lipids. In those cells that lack nuclei and other organelles, such as lensfiber cells and mammalianerythrocytes, IR-induced damage to macromolecules is retained because they cannot be easily replenished.Whilst the life span for an erythrocyte is several months, the life span of a human lens is decades. There is verylimited turnover in lens macromolecules, therefore the aging process greatly impacts lens structure and functionover its lifetime. The lens is a tissue where biomolecular longevity, lifelong retention of its components andcontinued growth are integral to its homeostasis. These characteristics make the lens an excellent model to studythe contribution of retained macromolecular damage over time. Epidemiological data have revealed a significantassociation between exposure to IR, the loss of lens optical function and the formation of cataracts (catar-actogenesis) later in life. Lifestyle, genetic and environmental factors all contribute to cataractogenesis due totheir effect on the aging process. Cataract is an iconic age-related disease in humans. IR is a recognised cause ofcataract and the occupational lens dose limit is reduced from 150 to 20 mGy / year averaged over 5 years (ICRPPublication 118). Understanding the effects of low dose IR on the lens and its role in cataractogenesis is thereforevery important. So we redefine“cataractogenic load”as a term to account for the combined lifestyle, genetic andenvironmental processes that increase biomolecular damage to lens macromolecules leading to cataract for-mation. These processes weaken metabolic defenses, increase post-translational protein modifications, and alterthe lipid structure and content of the lens. IR exposure is a significant insult to the lens because of free radicalgeneration and the ensuing oxidative stress. We support the concept that damage caused by IR compounds theaging process by increasing the cataractogenic load, hereby accelerating lens aging and its loss of function.
Uwineza, A., Kalligeraki, A. A., Hamada, N., Jarrin, M., & Quinlan, R. A. (2019). Cataractogenic load – A concept to study the contribution of ionizing radiation to accelerated aging in the eye lens. Mutation Research-Reviews in Mutation Research, 779, 68-81. doi:10.1016/j.mrrev.2019.02.004
Cataract risk in US radiologic technologists assisting with fluoroscopically guided interventional procedures: a retrospective cohort study
Objectives – To assess radiation exposure-related work history and risk of cataract and cataract surgery among radiologic technologists assisting with fluoroscopically guided interventional procedures (FGIP).
Methods – This retrospective study included 35 751 radiologic technologists who reported being cataract-free at baseline (1994–1998) and completed a follow-up questionnaire (2013–2014). Frequencies of assisting with 21 types of FGIP and use of radiation protection equipment during five time periods (before 1970, 1970–1979, 1980–1989, 1990–1999, 2000–2009) were derived from an additional self-administered questionnaire in 2013–2014. Multivariable-adjusted relative risks (RRs) for self-reported cataract diagnosis and cataract surgery were estimated according to FGIP work history.
Results – During follow-up, 9372 technologists reported incident physician-diagnosed cataract; 4278 of incident cases reported undergoing cataract surgery. Technologists who ever assisted with FGIP had increased risk for cataract compared with those who never assisted with FGIP (RR: 1.18, 95% CI 1.11 to 1.25). Risk increased with increasing cumulative number of FGIP; the RR for technologists who assisted with >5000 FGIP compared with those who never assisted was 1.38 (95% CI 1.24 to 1.53; p trend <0.001). These associations were more pronounced for FGIP when technologists were located ≤3 feet (≤0.9 m) from the patient compared with >3 feet (>0.9 m) (RRs for >5000 at ≤3 feet vs never FGIP were 1.48, 95% CI 1.27 to 1.74 and 1.15, 95% CI 0.98 to 1.35, respectively; pdifference=0.04). Similar risks, although not statistically significant, were observed for cataract surgery.
Conclusion – Technologists who reported assisting with FGIP, particularly high-volume FGIP within 3 feet of the patient, had increased risk of incident cataract. Additional investigation should evaluate estimated dose response and medically validated cataract type.
Velazquez-Kronen, R., Borrego, D., Gilbert, E., Miller, D., Moysich, K., Freudenheim, J., … Kitahara, C. (2019). Cataract risk in US radiologic technologists assisting with fluoroscopically guided interventional procedures: a retrospective cohort study. Occupational and Environmental Medicine, 76(5), 317–325. https://doi.org/10.1136/oemed-2018-105360
Influences of operator head posture and protective eyewear on eye lens doses in interventional radiology: A Monte Carlo Study
Purpose – To quantify the effects of operator head posture and different types of protective eyewear on the eye lens dose to operators in interventional radiology (IR).
Methods – A deformable computational human phantom, Rensselaer Polytechnic Institute (RPI) Adult Male, consisting of a high‐resolution eye model, was used to simulate a radiologist who is performing an interventional radiology procedure. The radiologist phantom was deformed to a set of different head postures. Three different protective eyewear models were incorporated into the posture‐deformed radiologist phantom. The eye lens dose of the radiologist was calculated using the Monte Carlo code, MCNP. Effects of the radiologist’s head posture and different types of protective eyewear on eye lens doses were studied. The relationship between efficacy of protective eyewear and the radiologist’s head posture was investigated. Effects of other parameters on efficacy of protective eyewear were also studied, including the angular position of the radiologist, the gap between the eyewear and the face of the radiologist, and the lead equivalent thickness.
Results – The dose to both lenses decreased by 80% as the head posture moved from looking downward to looking upward. Sports wrap glasses were found to reduce doses further than the other two studied models. The efficacy of eyewear was found to be related to radiologist’s head posture as well. When the radiologist was looking up, the protective eyewear almost provided no protection to both lenses. Other factors such as the face‐to‐eyewear distance and the lead equivalent thickness were also found to have an impact on the efficacy of protective eyewear. The dose reduction factor (DRF), defined as the ratio of the dose to the lens without protection to that with protection, decreased from 4.25 to 1.07 as the face‐to‐eyewear distance increased. The DRF almost doubled when the lead equivalent thickness increased from 0.07 to 0.35 mm. However, further increase in lead equivalent thickness showed little improvement in dose reduction.
Conclusion – The radiologist’s head posture has a significant influence on the eye lens dose in IR. Sports wrap protective eyewear which conforms to the curve of the face is essential for the radiation protection of the eye lens. However, the radiologist’s head posture and other exposure parameters should be considered when evaluating the protection of the radiologist’s eyes.
Mao, L., Liu, T., Caracappa, P., Lin, H., Gao, Y., Dauer, L., & Xu, X. (2019). Influences of operator head posture and protective eyewear on eye lens doses in interventional radiology: A Monte Carlo Study. Medical Physics, 46(6), 2744–2751. https://doi.org/10.1002/mp.13528
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Risk of radiation-induced lens opacities among surgeons and interventional medical staff
The main effect of ionizing radiation on the eyes is the onset of posterior cortical and subcapsular cataracts. Recent studies have raised questions about the mechanism of ocular damage and the threshold dose for the onset of such effects. Currently, operators may be exposed to ionizing radiation during surgical procedures. It has been estimated that urologists can be exposed to an annual dose close to or above 20 mSv/year. The aim of our study was to evaluate the frequency of cataracts in a group of professional radiological operators to verify their possible association with the radiation dose to the crystalline lens and the tasks performed. The records of 73 health workers exposed to ionizing radiation were reviewed. The average annual dose to the crystalline lens, the number of years of exposure, and the presence of radiation-compatible opacities were assessed for all operators. Lenticular opacities were observed in 16.4% of subjects. The presence of alterations was associated with exposure doses below 10 mSv and > 10 years’ experience in fluoroscopically guided procedures. Based on our results, protection of the crystalline lens against exposure to ionizing radiation by means of goggles is recommended. In addition, examination of the lens via slit lamp examination is recommended for all operators involved in interventional procedures with the current levels of radiation exposure.
Coppeta, L., Pietroiusti, A., Neri, A., Spataro, A., De Angelis, E., Perrone, S., & Magrini, A. (2019). Risk of radiation-induced lens opacities among surgeons and interventional medical staff. Radiological Physics and Technology, 12(1), 26–29. https://doi.org/10.1007/s12194-018-0487-9
2018
X-ray canary in the cath lab: Posterior cataracts
Cataract formation in the posterior subcapsular region of the lens is a lesion highly specific to both high-dose acute radiation exposure and chronic low-dose exposure. Low-dose radiation may not manifest lens changes for several decades after initial exposure. Cardiac catheterization team members need to be educated on, and protected from, this form of radiation injury as its long latency period between exposure and physical damage may acutely reduce the sense of hazard amongst healthcare radiation workers.
Ahmad, T., & Gilchrist, I. (2018). X‐ray canary in the cath lab: Posterior cataracts. Catheterization and Cardiovascular Interventions, 91(4), 655–656. https://doi.org/10.1002/ccd.27561
Always on my mind
This article is focused on occupational radiogenic brain tumors and some radioprotective techniques used to manage this risk. Published case reports have stimulated concern among operators. The anatomical pattern of tumor locations is not consistent with measured radiation dose distributions at operators’ heads. In addition, the lack of statistically positive findings in these reports, and a recently published survey on radiologist’s mortality both indicate that the current level of fluoroscopists’ radiation safety practices is likely to be adequate. This presumes that the rules of dose-management, time, distance, and shielding continue to be followed. These are briefly reviewed in this article. The use of radioprotective surgical caps is a current fashion. In clinical practice, these caps provide minimal reductions in brain dose and might induce operators to neglect applying the practical rules mentioned above. Appropriate management of personal, staff, and patient risk should always be on the radiologists’ mind.
Balter, S. (2018). Always on My Mind. Techniques in Vascular and Interventional Radiology, 21(1), 26-31. doi:https://doi.org/10.1053/j.tvir.2017.12.006
Protection evaluation of non-lead radiation-shielding fabric: preliminary exposure-dose study
Aim – The aim of this study was to evaluate the effectiveness and shielding performance of a novel recently developed non-lead radiation-shielding fabric containing bismuth oxide (BO-fabric).
Methods – BO-fabric was fabricated using urethane resin and bismuth nanopowder. A dose-measurement method was employed to evaluate the radiation-attenuation characteristics of the shielding fabric in accordance with the Korean Standards standard. The shielding performances (%) were calculated by measuring the radiation doses after lamination with increasing layers of fabric (1–10 layers). The physical performance of the fabric in terms of flexural and abrasion resistances was evaluated by the Korea Apparel Testing and Research Institute (KATRI).
Results – The radiation-attenuation capabilities of one layer of BO-fabric were 58.5, 49.9, and 43.0% at tube voltages of 60, 80, and 100 kVp, respectively. The radiation-shielding performance upon lamination of BO-fabric gradually increased as the number of layers increased. Excellent flexural and abrasion resistances were observed in the KATRI evaluation.
Conclusion – A non-lead radiation-shielding fabric based on urethane resin and bismuth was fabricated and examined, revealing an excellent shielding performance. Owing to the flexibility and simple operation of the fabric, it can be employed for various designs of clothing and protective apparel with many purposes.
Kang JH, Oh SH, Oh J-I, Kim S-H, Choi Y-S and Hwang E-H. Protection evaluation of non-lead radiation-shielding fabric: preliminary exposure-dose study. Oral radiology. 2018; 35: 224-9.
2017
The importance of vision (editorial comment - CCI)
Key Points
- Based on a systematic review and meta‐analysis of 8 studies, involving 2,559 subjects, both interventional cardiologists (3.21) and cardiac cath lab staff (2.76) had a significantly higher relative risk of posterior lens opacity than the control group.
- It is essential to provide “best practice” in radiation dose management and lead shielding in the cath lab with the standard “As Low As Reasonably Achievable”!
- There is a clear need for better data to quantitate the radiation risk and to design innovative strategies to decrease that risk.
Henry, T., & Henry, C. (2017). The importance of vision. Catheterization and Cardiovascular Intervention, 90(1), 10–11. https://doi.org/10.1002/ccd.27169
Occupational Radiation Exposure and Deaths From Malignant Intracranial Neoplasms of the Brain and CNS in U.S. Radiologic Technologists
Objectives – Childhood exposure to acute, high-dose radiation has consistently been associated with risk of benign and malignant intracranial tumors of the brain and CNS, but data on risks of adulthood exposure to protracted, low-to-moderate doses of radiation are limited. In a large cohort of radiologic technologists, we quantified the association between protracted, low-to-moderate doses of radiation and malignant intracranial tumor mortality.
Materials and Methods – The study population included 83,655 female and 26,642 male U.S. radiologic technologists who were certified for at least 2 years as of 1982. The cohort was followed from the completion date of the first or second survey (1983–1989 or 1994–1998) to the date of death, loss to follow-up, or December 31, 2012, whichever was earliest. Occupational brain doses through 1997 were based on work history, historical data, and, for most years after the mid 1970s, individual film badge measurements. Radiation-related excess relative risks (ERRs) and 95% CIs were estimated from Poisson regression models adjusted for attained age and sex.
Results – Cumulative mean absorbed brain dose was 12 mGy (range, 0–290 mGy). During follow-up (median, 26.7 years), 193 technologists died of a malignant intracranial neoplasm. Based on models incorporating a 5-year lagged cumulative brain dose, cumulative brain dose was not associated with malignant intracranial tumor mortality (overall ERR per 100 mGy, 0.1; 95% CI, < −0.3 to 1.5). No effect modification was observed by sex or birth cohort.
Conclusion – In this nationwide cohort of radiologic technologists, cumulative occupational radiation exposure to the brain was not associated with malignant intracranial tumor mortality.
Kitahara, C. M., Linet, M. S., Balter, S., Miller, D. L., Rajaraman, P., Cahoon, E. K., . . . Preston, D. L. (2017). Occupational Radiation Exposure and Deaths From Malignant Intracranial Neoplasms of the Brain and CNS in U.S. Radiologic Technologists, 1983-2012. AJR. American journal of roentgenology, 208(6), 1278. doi:10.2214/AJR.16.16964
Risk of cataract among interventional cardiologists and catheterization lab staff: A systematic review and meta‐analysis
Objectives – We performed a systematic review and meta‐analysis to assess the risk of developing a radiation‐induced cataract in interventional cardiologists (ICs).
Background – ICs are forced to radiation exposure during cardiac catheterization procedures. Since the eye lens is one of the most radiosensitive organs in the body, ICs are highly susceptible to develop a radiation‐induced cataract.
Method – We performed a systematic literature search of nine electronic databases to retrieve studies that report cataract among interventional cardiologists. Records were screened for eligibility and data were extracted and analyzed using review manager (RevMan) for windows.
Results – Eight studies involving 2559 subjects (exposed ICs = 1224) were included. Posterior lens opacity was significantly higher in ICs relative to the control group (RR= 3.21, 95% CI [2.14, 4.83], P < 0.00001). In contrast, there was no significant difference between both groups in cortical lens opacity (RR= 0.69, 95% CI [0.46, 1.06], P = 0.09) and nuclear opacity (RR= 0.85, 95% CI [0.71, 1.02], P = 0.08).
Conclusion – Interventional cardiologists are at high risk of developing radiation‐induced cataract; therefore, protective measures with high safety rates should be implied. © 2017 Wiley Periodicals, Inc.
Elmaraezy, A., Morra, M., Mohammed, A., Al-Habaa, A., Elgebaly, A., Ghazy, A., … Hirayama, K. (2017). Risk of cataract among interventional cardiologists and catheterization lab staff: A systematic review and meta-analysis. Catheterization And Cardiovascular Interventions, 90(1), 1–9. https://doi.org/10.1002/ccd.27114
Head and Neck Radiation Dose and Radiation Safety for Interventional Physicians
Objectives
The first aim of this study was to assess the magnitude of radiation dose to tissues of the head and neck of physicians performing x-ray-guided interventional procedures. The second aim was to assess protection of tissues of the head offered by select wearable radiation safety devices.
Background
Radiation dose to tissues of the head and neck is of significant interest to practicing interventional physicians. However, methods to estimate radiation dose are not generally available, and furthermore, some of the available research relating to protection of these tissues is misleading.
Methods
Using a single representative geometry, scatter radiation dose to a humanoid phantom was measured using radiochromic film and normalized by the radiation dose to the left collar of the radioprotective thorax apron. Radiation protection offered by leaded glasses and by a radioabsorbent surgical cap was measured.
Results
In the test geometry, average radiation doses to the unprotected brain, carotid arteries, and ocular lenses were 8.4%, 17%, and 50% of the dose measured at the left collar, respectively. Two representative types of leaded glasses reduced dose to the ocular lens on the side of the physician from which the scatter originates by 27% to 62% but offered no protection to the contralateral eye. The radioabsorbent surgical cap reduced brain dose by only 3.3%.
Conclusions
A method by which interventional physicians can estimate dose to head and neck tissues on the basis of their personal dosimeter readings is described. Radiation protection of the ocular lenses by leaded glasses may be incomplete, and protection of the brain by a radioabsorbent surgical cap was minimal.
Fetterly K, Schueler B, Grams M, Sturchio G, Bell M and Gulati R. Head and Neck Radiation Dose and Radiation Safety for Interventional Physicians. JACC Cardiovasc Interv. 2017; 10: 520-8.
Link to full text
Eye lens dosimetry and the study on radiation cataract in interventional cardiologists
Purpose
To determine the eye lens dose of the Interventional Cardiology (IC) personnel using optically stimulated luminescent dosimeter (OSLD) and the prevalence and risk of radiation – associated lens opacities in Thailand.
Methods and results
48 IC staff, with age- and sex- matches 37 unexposed controls obtained eye examines. Posterior lens change was graded using a modified Merriam-Focht technique by two independent ophthalmologists. Occupational exposure (mSv) was measured in 42 IC staff, using 2 OSLD badges place at inside lead apron and at collar. Annual eye lens doses (mSv) were also measured using 4 nanoDots OSL placed outside and inside lead glass eyewear. The prevalence of radiation-associated posterior lens opacities was 28.6% (2/7) for IC, 19.5% (8/41) for nurses, and 2.7% (1/37) for controls. The average and range of annual whole body effective dose, Hp(10), equivalent dose at skin of the neck, Hp(0.07) and equivalent dose at eye lens, Hp(3) were 0.80 (0.05–6.79), 5.88 (0.14–35.28), and 5.73 (0.14–33.20) mSv respectively. The annual average and range of eye lens dose using nano Dots OSL showed the outside lead glass eyewear on left and right sides as 8.06 (0.17–32.45), 3.55(0.06–8.04) mSv and inside left and right sides as 3.91(0.05–14.26) and 2.44(0.06–6.24) mSv respectively.
Conclusion
Eye lens doses measured by OSLD badges and nano Dot dosimeter as Hp(10), Hp(0.07) and Hp(3). The eyes of the IC personnel were examined annually by two ophthalmologists for the prevalence of cataract induced by radiation.
Matsubara K, Lertsuwunseri V, Srimahachota S, et al. Eye lens dosimetry and the study on radiation cataract in interventional cardiologists. Phys Med. 2017; 44: 232-5.
Occupational eye dose in interventional cardiology procedures
It is important to measure the radiation dose [3-mm dose equivalent, Hp(3)] in the eye. This study was to determine the current occupational radiation eye dose of staff conducting interventional cardiology procedures, using a novel direct eye dosimeter. We measured the occupational eye dose [Hp(3)] in physicians and nurses in a catheterization laboratory for 6-months. The eye doses [Hp(3)] of 12 physicians (9 with Pb glasses, 3 without), and 11 nurses were recorded using a novel direct eye dosimeter, the DOSIRISTM. We placed dosimeters above and under the glasses. We also estimated the eye dose [0.07-mm dose equivalent] using a neck personal dosimeter. The eye doses among interventional staff ranked in the following order: physicians without Pb glasses > physicians with Pb glasses > nurses. The shielding effect of the glasses (0.07-mm Pb) in a clinical setting was approximately 60%. In physicians who do not wear Pb glasses, the eye dose may exceed the new regulatory limit for IR staff. We found good correlations between the neck dosimeter dose and eye dosimeter dose (inside or outside glasses, R2 = 0.93 and R2 = 0.86, respectively) in physicians. We recommend that interventional physicians use an eye dosimeter for correct evaluation of the lens dose.
Haga Y, Chida K, Kaga Y, Sota M, Meguro T, Zuguchi M. Occupational eye dose in interventional cardiology procedures. Scientific Reports (Nature Publisher Group) 2017;7:1.
2016
Occupational eye lens dose in interventional radiology and cardiology: new insights
Interventional radiology and cardiology procedures deliver high radiation dose to physicians and interventional suite staff. Nowadays the interest has been focused on occupational dose to the lens of the eye. Recent epidemiological studies have shown that radiation-induced cataract is observed in lower dose threshold than the previous considered by ICRP 103. Based on these studies, in 2011, ICRP reduced the annual occupational dose limit for the lens of the eye to 20 mSv while the dose threshold was determined 0.5 Gy. Many reports have demonstrated that the occupational ocular dose may exceed the new annual limit if radiation protection equipment is not used. New considerations regarding the dose to the eye necessitate the education of medical personnel on radiation protection issues and the dosimetry of the lens in clinical routine.
Efstathopoulos, E. P. (2016). Occupational eye lens dose in interventional radiology and cardiology: new insights. Imaging in Medicine, 8(1), 1-2.
Eye dose to staff involved in interventional and procedural fluoroscopy itle
In 2011 the International Commission on Radiological Protection (ICRP) lowered the occupational eye dose limit from 150 to 20 mSv/yr [1]. While international jurisdictions are in a process of adopting these substantial changes, medical physicists at the clinical level have been advising medical colleagues on specific situations based on dose measurements. Commissioned and calibrated TLDs mounted in commercially available holders designed to simulate the measurement of Hp(3), were applied to staff involved in x-ray procedures for a one month period. During this period clinical procedure data was concurrently collected and subject to audit. The use or not of eye personal protective equipment (PPE) was noted for all staff. Audits were conducted in the cardiac catheterisation laboratory, the interventional angiography rooms and the procedural room where endoscopic retrograde cholangiopancreatography (ERCP) procedures are performed. Significant levels of occupational dose were recorded in the cardiac and interventional procedures, with maximum reading exceeding the new limit for some interventional radiologists. No significant eye doses were measured for staff performing ERCP procedures. One outcome of the studies was increased use of eye PPE for operators of interventional equipment with increased availability also to nursing staff, when standing in close proximity to the patient during procedures.
McLean D, Hadaya D, Tse J. Eye dose to staff involved in interventional and procedural fluoroscopy. Journal of Physics: Conference Series. 2016;694(1).
Correlation between scatter radiation dose at height of operator's eye and dose to patient for different angiographic projections
Highlights
- A method is presented to estimate the scatter radiation dose at operator eye height.
- The method allows estimating scatter radiation dose measuring ambient dose equivalent.
- Operator could exceed threshold for lens opacities if protection tools are not used.
- There is a good linear correlation between kerma-area product and scatter radiation dose.
- Different C-arm angulations can modify the scatter dose rate.
Abstract – Studies have reported cases of radiation-induced cataract among cardiology professionals. In view of the evidence of epidemiological studies, the ICRP recommends a new threshold for opacities and a new radiation dose to eye lens limit of 20 mSv per year for occupational exposure. The aim of this paper is to report scattered radiation doses at the height of the operator’s eye in an interventional cardiology facility without considering radiation protection devices and to correlate these values with different angiographic projections and operational modes. Measurements were taken in a cardiac laboratory with an angiography X-ray system equipped with flat-panel detector. PMMA plates of 30×30×5 cm were used with a thickness of 20 cm. Measurements were taken in two fluoroscopy modes (low and normal, 15 pulses/s) and in cine mode (15 frames/s). Four angiographic projections were used: anterior posterior; lateral; left anterior oblique caudal (spider); and left anterior oblique cranial, with a cardiac protocol for patients weighing between 70 and 90 kg. Measurements of phantom entrance dose rate and scatter dose rate were performed with two Unfors Xi plus detectors. The detector measuring scatter radiation was positioned at the usual distance of the cardiologist’s eyes during working conditions. There is a good linear correlation between the kerma area product and scatter dose at the lens. Experimental correlation factors of 2.3, 12.0, 12.2 and 17.6 μSv/Gy cm2 were found for different projections. PMMA entrance dose rates for low and medium fluoroscopy and cine modes were 13, 39 and 282 mGy/min, respectively, for AP projection.
Leyton, F., Nogueira, M. S., Gubolino, L. A., Pivetta, M. R., & Ubeda, C. (2016). Correlation between scatter radiation dose at height of operator’s eye and dose to patient for different angiographic projections. Applied Radiation and Isotopes, 117, 100-105. doi:http://dx.doi.org/10.1016/j.apradiso.2016.01.013
2015
Assessment of Eye Lens Doses for Workers During Interventional Radiology Procedures
The assessment of eye lens doses for workers during interventional radiology (IR) procedures was performed using a new eye lens dosemeter. In parallel, the results of routine individual monitoring were analysed and compared with the results obtained from measurements with a new eye lens dosemeter. The eye lens doses were assessed using Hp(3) measured at the level of the eyes and were compared with Hp(10) measured with the whole-body dosemeter above the lead collar. The information about use of protective measures, the number of performed interventional procedures per month and their fluoroscopy time was also collected. The assessment of doses to the lens of the eye was done for 50 IR workers at 9 Lithuanian hospitals for the period of 2012–2013. If the use of lead glasses is not taken into account, the estimated maximum annual dose equivalent to the lens of the eye was 82 mSv.
Urboniene A, Sadzeviciene E, Ziliukas J. Assessment of Eye Lens Doses for Workers During Interventional Radiology Procedures Radiation Protection Dosimetry 2015;165(1-4):299-303. doi:https://doi.org/10.1093/rpd/ncv173
Eye Lens Dose in Interventional Cardiology
The ICRP has recently recommended reducing the occupational exposure dose limit for the lens of the eye to 20 mSv y(-1), averaged over a period of 5 y, with no year exceeding 50 mSv, instead of the current 150 mSv y(-1). This reduction will have important implications for interventional cardiology and radiology (IC/IR) personnel. In this work, lens dose received by a staff working in IC is studied in order to determine whether eye lens dose monitoring or/and additional radiological protection measures are required. Eye lens dose exposure was monitored in 10 physicians and 6 nurses. The major IC procedures performed were coronary angiography and percutaneous transluminal coronary angioplasty. The personnel were provided with two thermoluminescent dosemeters (TLDs): one calibrated in terms of Hp(3) located close to the left ear of the operator and a whole-body dosemeter calibrated in terms of Hp(10) and Hp(0.07) positioned on the lead apron. The estimated annual eye lens dose for physicians ranged between 8 and 60 mSv, for a workload of 200 procedures y(-1). Lower doses were collected for nurses, with estimated annual Hp(3) between 2 and 4 mSv y(-1). It was observed that for nurses the Hp(0.07) measurement on the lead apron is a good estimate of eye lens dose. This is not the case for physicians, where the influence of both the position and use of protective devices such as the ceiling shield is very important and produces large differences among doses both at the eyes and on the thorax. For physicians, a good correlation between Hp(3) and dose area product is shown.
Principi S, Soler CD, Ginjaume M, Vilagrasa MB, Escutia JJR, Duch MA. Eye Lens Dose in Interventional Cardiology. Radiation Protection Dosimetry. 2015;165(1-4):289-293. doi: 10.1093/rpd/ncv051
Eye lens monitoring for interventional radiology personnel: dosemeters, calibration and practical aspects of H-p(3) monitoring. A 2015 review
A thorough literature review about the current situation on the implementation of eye lens monitoring has been performed in order to provide recommendations regarding dosemeter types, calibration procedures and practical aspects of eye lens monitoring for interventional radiology personnel. Most relevant data and recommendations from about 100 papers have been analysed and classified in the following topics: challenges of today in eye lens monitoring; conversion coefficients, phantoms and calibration procedures for eye lens dose evaluation; correction factors and dosemeters for eye lens dose measurements; dosemeter position and influence of protective devices. The major findings of the review can be summarised as follows: the recommended operational quantity for the eye lens monitoring is H p (3). At present, several dosemeters are available for eye lens monitoring and calibration procedures are being developed. However, in practice, very often, alternative methods are used to assess the dose to the eye lens. A summary of correction factors found in the literature for the assessment of the eye lens dose is provided. These factors can give an estimation of the eye lens dose when alternative methods, such as the use of a whole body dosemeter, are used. A wide range of values is found, thus indicating the large uncertainty associated with these simplified methods. Reduction factors from most common protective devices obtained experimentally and using Monte Carlo calculations are presented. The paper concludes that the use of a dosemeter placed at collar level outside the lead apron can provide a useful first estimate of the eye lens exposure. However, for workplaces with estimated annual equivalent dose to the eye lens close to the dose limit, specific eye lens monitoring should be performed. Finally, training of the involved medical staff on the risks of ionising radiation for the eye lens and on the correct use of protective systems is strongly recommended.
Carinou E, Ferrari P, Bjelac OC, Gingaume M, Merce MS, O’Connor U. Eye lens monitoring for interventional radiology personnel: dosemeters, calibration and practical aspects of H-p(3) monitoring. A 2015 review. Journal of Radiological Protection. 2015;35(3):R17-R34. doi:10.1088/0952-4746/35/3/R17
Invasive Cardiologists Are Exposed to Greater Left Sided Cranial Radiation: The BRAIN Study
Objectives – This study sought to determine radiation exposure across the cranium of cardiologists and the protective ability of a nonlead, XPF (barium sulfate/bismuth oxide) layered cap (BLOXR, Salt Lake City, Utah) during fluoroscopically guided, invasive cardiovascular (CV) procedures.
Background – Cranial radiation exposure and potential for protection during contemporary invasive CV procedures is unclear.
Methods – Invasive cardiologists wore an XPF cap with radiation attenuation ability. Six dosimeters were fixed across the outside and inside of the cap (left, center, and right), and 3 dosimeters were placed outside the catheterization lab to measure ambient exposure.
Results – Seven cardiology fellows and 4 attending physicians (38.4 ± 7.2 years of age; all male) performed diagnostic and interventional CV procedures (n = 66.2 ± 27 cases/operator; fluoroscopy time: 14.9 ± 5.0 min). There was significantly greater total radiation exposure at the outside left and outside center (106.1 ± 33.6 mrad and 83.1 ± 18.9 mrad) versus outside right (50.2 ± 16.2 mrad; p < 0.001 for both) locations of the cranium. The XPF cap attenuated radiation exposure (42.3 ± 3.5 mrad, 42.0 ± 3.0 mrad, and 41.8 ± 2.9 mrad at the inside left, inside center, and inside right locations, respectively) to a level slightly higher than that of the ambient control (38.3 ± 1.2 mrad, p = 0.046). After subtracting ambient radiation, exposure at the outside left was 16 times higher than the inside left (p < 0.001) and 4.7 times higher than the outside right (p < 0.001). Exposure at the outside center location was 11 times higher than the inside center (p < 0.001), whereas no difference was observed on the right side.
Conclusions – Radiation exposure to invasive cardiologists is significantly higher on the left and center compared with the right side of the cranium. Exposure may be reduced similar to an ambient control level by wearing a nonlead XPF cap
Reeves RR, Ang L, Bahadorani J, et al. Invasive Cardiologists Are Exposed to Greater Left Sided Cranial Radiation The BRAIN Study (Brain Radiation Exposure and Attenuation During Invasive Cardiology Procedures). JACC – Cardiovascular Interventions. 2015;8(9):1197-1206. doi: 10.1016/j.jcin.2015.03.027.
Dose limits to the lens of the eye: International Basic Safety Standards and related guidance
The International Atomic Energy Agency (IAEA) safety requirements: ‘General Safety Requirements Part 3–Radiation protection and safety of radiation sources: International Basic Safety Standards’ (BSS) was approved by the IAEA Board of Governors at its meeting in September 2011, and was issued as General Safety Requirements Part 3 in July 2014. The equivalent dose limit for the lens of the eye for occupational exposure in planned exposure situations was reduced from 150 mSv year(-1) to 20 mSv year(-1), averaged over defined periods of 5 years, with no annual dose in a single year exceeding 50 mSv. This reduction in the dose limit for the lens of the eye followed the recommendation of the International Commission on Radiological Protection in its statement on tissue reactions of 21 April 2011. IAEA has developed guidance on the implications of the new dose limit for the lens of the eye. This paper summarises the process that led to the inclusion of the new dose limit for the lens of the eye in the BSS, and the implications of the new dose limit.
Boal TJ, Pinak M. Dose limits to the lens of the eye: International Basic Safety Standards and related guidance. Annals of the ICRP. 2015;44(1_suppl):112-117. doi: 10.1177/0146645314562321
2014
Cranial radiation exposure during cerebral catheter angiography
Background – Radiation exposure to patients and personnel remains a major concern in the practice of interventional radiology, with minimal literature available on exposure to the forehead and cranium.
Objective – In this study, we measured cranial radiation exposure to the patient, operating interventional neuroradiologist, and circulating nurse during neuroangiographic procedures. We also report the effectiveness of wearing a 0.5 mm lead equivalent cap as protection against radiation scatter.
Design – 24 consecutive adult interventional neuroradiology procedures (six interventional, 18 diagnostic) were prospectively studied for cranial radiation exposures in the patient and personnel. Data were collected using electronic detectors and thermoluminescent dosimeters.
Results – Mean fluoroscopy time for diagnostic and interventional procedures was 8.48 (SD 2.79) min and 26.80 (SD 6.57) min, respectively. Mean radiation exposure to the operator’s head was 0.08 mSv, as measured on the outside of the 0.5 mm lead equivalent protective headgear. This amounts to around 150 mSv/year, far exceeding the current deterministic threshold for the lens of the eye (ie, 20 mSv/year) in high volume centers performing up to five procedures a day. When compared with doses measured on the inside of the protective skullcap, there was a statistically significant reduction in the amount of radiation received by the operator’s skull.
Conclusions – Our study suggests that a modern neurointerventional suite is safe when equipped with proper protective shields and personal gear. However, cranial exposure is not completely eliminated with existing protective devices and the addition of a protective skullcap eliminates this exposure to both the operator and support staff.
Chohan MO, Sandoval D, Buchan A, Murray-Krezan C, Taylor CL. Cranial radiation exposure during cerebral catheter angiography. Journal of neurointerventional surgery. 2014;6(8):633-636. doi: 10.1136/neurintsurg-2013-010909
Implications for Occupational Radiation Protection of the New Dose Limit for the Lens of the Eye
Background – The IAEA Safety Requirements publication: GSR Part 3 (Interim edition): Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards, was approved by the IAEA Board of Governors in September 2011 and issued as an interim edition in November 2011. The equivalent dose limit for the lens of the eye for occupational exposure in planned exposure situations was reduced from 150 mSv per year to 20 mSv per year, averaged over defined periods of five years, with no single year exceeding 50 mSv.
Purpose – The purpose of the TECDOC is to provide guidance on implementing the new occupational dose limit and to identify issues for which further information is required. In the longer term, the guidance will form the
basis for the guidance in relation to the new dose limit for the lens of the eye in the Safety Guides DS453: Occupational Radiation Protection and DS399: Radiation Safety in the Medical Uses of Ionizing Radiation.
Implications for Occupational Radiation Protection of the New Dose Limit for the Lens of the Eye. In: Agency IAE, ed. IAEA_TECDOC. Vol 1731. Vienna 2014.
Implications in dosimetry of the implementation of the revised dose limit to the lens of the eye
In 2012, International Radiation Protection Association (IRPA) established a Task Group to provide an assessment of the impact of the implementation of the ICRP-revised dose limit for the lens of the eye for occupational exposure. Associated Societies (ASs) of IRPA were asked to provide views and comments on the basis of a questionnaire addressing three principal topics: (i) implications for dosimetry, (ii) implications for methods of protection and (iii) wider implications of implementing the revised limits. A summary of the collated responses regarding dosimetry is presented and discussed. There is large agreement on the most critical aspects and difficulties in setting up an appropriate monitoring programme for the lens of the eyes. The recent international standards and technical documents provide guidance for some of the concerns but other challenges remain in terms of awareness, acceptance and practicalities.
Broughton J, Cantone MC, Ginjaume M, Shah B, Czarwinski R. Implications in dosimetry of the implementation of the revised dose limit to the lens of the eye. Radiation protection dosimetry. 2014:ncu320. doi:10.1093/rpd/ncu320
A report on increased brain tumors among physicians working in the cath lab
Physicians performing interventional procedures are chronically exposed to ionizing radiation, which is known to pose increased cancer risks. We recently reported 9 cases of brain cancer in interventional cardiologists. Subsequently, we received 22 additional cases from around the world, comprising an expanded 31 case cohort. Data were transmitted to us during the past few months. For all cases, where possible, we endeavored to obtain the baseline data, including age, gender, tumor type, and side involved, specialty (cardiologist vs radiologist), and number of years in practice. These data were obtained from the medical records, interviews with patients, when possible, or with family members and/or colleagues. The present report documented brain and neck tumors occurring in 31 physicians: 23 interventional cardiologists, 2 electrophysiologists, and 6 interventional radiologists. All physicians had worked for prolonged periods (latency period 12 to 32 years, mean 23.5 ± 5.9) in active interventional practice with exposure to ionizing radiation in the catheterization laboratory. The tumors included 17 cases (55%) of glioblastoma multiforme (GBM), 2 astrocytomas (7%), and 5 meningiomas (16%). In 26 of 31 cases, data were available regarding the side of the brain involved. The malignancy was left sided in 22 (85%), midline in 1, and right sided in 3 operators. In conclusion, these results raise additional concerns regarding brain cancer developing in physicians performing interventional procedures. Given that the brain is relatively unprotected and the left side of the head is known to be more exposed to radiation than the right, these findings of disproportionate reports of left-sided tumors suggest the possibility of a causal relation to occupational radiation exposure.
Roguin A. Radiation hazards to interventional cardiologists: A report on increased brain tumors among physicians working in the cath lab. SOLACI; April 23, 2014, 2014; Buenos Aires, Argentina. doi: 10.1016/j.amjcard.2012.12.060
2013
Radiation-associated lens opacities in catheterization personnel: Results of a survey and direct assessments
Purpose – To estimate ocular radiation doses and prevalence of lens opacities in a group of interventional catheterization professionals and offer practical recommendations based on these findings to avoid future lens damage.
Materials and Methods – Subjects included 58 physicians and 69 nurses and technicians attending an interventional cardiology congress and appropriate unexposed age-matched controls. Lens dose estimates were derived from combining experimental measurements in catheterization laboratories with questionnaire responses regarding workload, types of procedures, and use of eye protection. Lens opacities were observed by dilated slit lamp examination using indirect illumination and retroillumination. The frequency and severity of posterior lens changes were compared between the exposed and unexposed groups. The severity of posterior lens changes was correlated with cumulative eye dose.
Results – Posterior subcapsular lens changes characteristic of ionizing radiation exposure were found in 50% of interventional cardiologists and 41% of nurses and technicians compared with findings of similar lens changes in<10% of controls. Estimated cumulative eye doses ranged from 0.1-18.9 Sv. Most lens injuries result after several years of work without eye protection.
Conclusions – A high prevalence of lens changes likely induced by radiation exposure in the study population suggests an urgent need for improved radiation safety and training, use of eye protection during catheterization procedures, and improved occupational dosimetry.
Vano E, Kleiman NJ, Duran A, Romano-Miller M, Rehani MM. Radiation-associated lens opacities in catheterization personnel: Results of a survey and direct assessments. Journal of Vascular and Interventional Radiology. 2013;24(2):197-204. doi: 10.1016/j.jvir.2012.10.016
Eye lens dosimetry in interventional cardiology: Results of staff dose measurements and link to patient dose levels
Workers involved in interventional cardiology procedures receive high eye lens dose if protection is not used. Currently, there is no suitable method for routine use for the measurement of eye dose. Since most angiography machines are equipped with suitable patient dosemeters, deriving factors linking staff eye doses to the patient doses can be helpful. In this study the patient kerma-area product, cumulative dose at an interventional reference point and eye dose in terms of Hp(3) of the cardiologists, nurses and radiographers for interventional cardiology procedures have been measured. Correlations between the patient dose and the staff eye dose were obtained. The mean eye dose was 121 µSv for the first operator, 33 µSv for the second operator/nurse and 12 µSv for radiographer. Normalised eye lens doses per unit kerma-area product were 0.94 µSv Gy⁻¹ cm⁻² for the first operator, 0.33 µSv Gy⁻¹ cm⁻² for the second operator/nurse and 0.16 µSv Gy⁻¹ cm⁻² for radiographers. Statistical analysis indicated that there is a weak but significant (p < 0.01) correlation between the eye dose and the kerma-area product for all three staff categories. These values are based on a local practice and may provide useful reference for other studies for validation and for wider utilisation in assessing the eye dose using patient dose values.
Antic V, Ciraj-Bjelac O, Rehani M, Aleksandric S, Arandjic D, Ostojic M. Eye lens dosimetry in interventional cardiology: Results of staff dose measurements and link to patient dose levels. Radiation Protection Dosimetry. 2013;154(3):276-284. doi:10.1093/rpd/ncs236
Interventional cardiologists and risk of radiation-induced cataract: Results of a French multicenter observational study
Background – Interventional cardiologists (ICs) are exposed to X-rays and may be at risk to develop cataract earlier than common senile cataract. Excess risk of posterior subcapsular cataract, known as radiation-induced, was previously observed in samples of ICs from Malaysia, and Latin America. The O’CLOC study (Occupational Cataracts and Lens Opacities in interventional Cardiology) was performed to quantify the risk at the scale of France.
Methods – This cross-sectional multicenter study included an exposed group of ICs from different French centers and an unexposed control group of non-medical workers. Individual information was collected about cataract risk factors and past and present workload in catheterization laboratory. All participants had a clinical eye examination to classify the lens opacities (nuclear, cortical, or posterior subcapsular) with the international standard classification LOCS III.
Results – The study included 106 ICs (mean age=51±7 years) and 99 unexposed control subjects (mean age=50±7 years). The groups did not differ significantly in the prevalence of either nuclear or cortical lens opacities (61% vs. 69% and 23% vs. 29%, respectively). However, posterior subcapsular lens opacities, were significantly more frequent among ICs (17% vs. 5%, p=0.006), for an OR=3.9 [1.3–11.4]. The risk increased with duration of activity but no clear relationship with workload was observed. However, the risk appeared lower for regular users of protective lead glasses (OR=2.2 [0.4–12.8]).
Conclusions – ICs, in France as elsewhere, are at high risk of posterior subcapsular cataracts. Use of protective equipment against X-rays, in particular lead glasses, is strongly recommended to limit this risk.
Jacob S, Boveda S, Bar O, et al. Interventional cardiologists and risk of radiation-induced cataract: Results of a French multicenter observational study. International Journal of Cardiology. 2013;167(5):1843-1847. doi: https://doi.org/10.1016/j.ijcard.2012.04.124
2012
A study of the dose distribution in the region of the eye lens and extremities for staff working in interventional cardiology
Highlights
- The occupational doses in interventional cardiology were analyzed.
- The dose distributions at the region of eye lens and extremities were investigated.
- Large variations in doses were observed depending on some parameters.
- It was estimated that the occupational limit for the eye lens might be exceeded.
- The best position for the eye lens dosimeter for CA PCI procedures was found.
Abstract
The dose distributions at the region of eye lens and extremities of staff working in interventional cardiology were analyzed. The doses to physicians and nurses from three hospitals in Poland were measured with TL dosimeters (MCP-N) located on various places near eyebrows, on both fingers, wrists, knees and on the ankle. The procedures under investigation were coronary angiography (CA) and percutaneous coronary intervention (PCI), peacemaker and defibrillator implantations (PM/ICDs), cardiac resynchronization therapy with or without defibrillator implantations (CRT-D or CRT) and radiofrequency ablations (RFA). The study aimed at analyzing the distribution of radiation in selected anatomic regions, determining the typical locations of highest doses and estimating the dose ranges for selected types of procedures.
The maximum registered doses per procedure to eye lens and ankle were 1.21 mSv and 1.46 mSv for CA PCI procedures, 0.02 mSv and 0.05 mSv for RFA and 0.13 mSv and 0.51 mSv for PM/ICDs, respectively. The maximum doses to fingers, wrists and knees were, accordingly, 2.11 mSv, 1.07 mSv and 0.77 mSv for CA PCI procedures, 0.38 mSv, 0.20 mSv and 0.04 mSv for RFA ones, 0.50 mSv, 0.25 mSv and 0.01 mSv for PM/ICDs procedures and 2.25 mSv, 1.12 mSv and 0.58 mSv for CRT and CRT-D ones. The factors which might influence the dose like utilized radiation, availability of additional protective equipment and position of the staff with respect to X-ray source were also analyzed.
The annual doses for eye lens and extremities were estimated on the basis of individual annual workloads of the physicians participating in the study. The highest annual doses were revealed for physicians performing CA PCI procedures. Annual eye lens doses range up to 247 mSv indicating that the occupational limit for eye lens 150 mSv has been surpassed. In case of extremities the maximal estimated annual doses were 355 mSv, 136 mSv, 55 mSv and 328 mSv, for fingers, wrists, knees and for ankle, respectively. Moreover, in the light of ICRP new Statement on Tissue Reactions raising the possibility of lowering the annual limit for the lens of the eye the annual doses estimated in our paper indicate that for some procedures the monitoring of eye lens doses should be considered. On the other hand, it is important to note that most of high occupational doses can be easily avoided if radiation protection tools are used and, moreover, used properly.
The present survey is a part of ORAMED project concerning the determination of doses to extremities (fingers, wrists and knees) and eye lens during interventional procedures and includes the detailed analyses of results of Polish partner. They are, however, presented in wider context. The study is additionally extended by the investigation of the dose distribution at the eyebrows and ankle level.
Domienik J, Brodecki M, Rusicka D. A study of the dose distribution in the region of the eye lens and extremities for staff working in interventional cardiology. Radiation Measurements. 2012;47(2):130-138. doi: https://doi.org/10.1016/j.radmeas.2011.12.004
Radiation-Induced Eye Lens Changes and Risk for Cataract in Interventional Cardiology
Background – Recent studies have reported a significant increase in eye lens opacities among staff in the cardiac catheterization laboratory but indicated further studies are needed to confirm the findings.
Objective – To evaluate the prevalence of opacities in eyes of cardiologists, radiographers and nurses working in interventional cardiology.
Methods – The eyes of 52 staff in interventional cardiology facilities and 34 age- and sex-matched unexposed controls were screened in a cardiology conference held in Kuala Lumpur by dilated slit-lamp examination, and posterior lens changes were graded. Individual cumulative lens X-ray exposures were calculated from responses to a questionnaire in terms of workload and working practice.
Results – The prevalence of posterior lens opacities among interventional cardiologists was 53%, while in nurses and radiographers it was 45%. Corresponding relative risks were 2.6 (95% CI: 1.2-5.4) and 2.2 (95% CI: 0.98-4.9), for interventional cardiologists and support staff, respectively.
Conclusions – This study confirms a statistically significant increase in radiation-associated posterior lens changes in the eyes of interventional cardiology staff.
Ciraj-Bjelac O, Rehani M, Minamoto A, Sim KH, Liew HB, Vano E. Radiation-Induced Eye Lens Changes and Risk for Cataract in Interventional Cardiology. Cardiology. 2012;123(3):168-171. doi: 10.1159/000342458
2011
Measurements of eye lens doses in interventional radiology and cardiology: Final results of the ORAMED project
Within the ORAMED project (Optimization of Radiation Protection of Medical Staff) a coordinated measurement program for occupationally exposed medical staff was performed in different hospitals in Europe (www.oramed-fp7.eu). The main objective was to obtain a set of standardized data on extremity and eye lens doses for staff involved in interventional radiology and cardiology and to optimize radiation protection. Special attention was given to the measurement of the doses to the eye lenses. In this paper an overview will be given of the measured eye lens doses and the main influence factors for these doses. The measured eye lens doses are extrapolated to annual doses. The extrapolations showed that monitoring of the eye lens should be performed on routine basis.
Vanhavere F, Carinou E, Domienik J, et al. Measurements of eye lens doses in interventional radiology and cardiology: Final results of the ORAMED project. Radiation Measurements. 2011;46(11):1243-1247. doi.org/10.1016/j.radmeas.2011.08.013
2010
Risk for radiation-induced cataract for staff in interventional cardiology: Is there reason for concern?
Objectives – To examine the prevalence of radiation-associated lens opacities among interventional cardiologists and nurses and correlate with occupational radiation exposure.
Background – Interventional cardiology personnel are exposed to relatively high levels of X-rays and based on recent findings of radiation-associated lens opacities in other cohorts, they may be at risk for cataract without use of ocular radiation protection.
Methods – Eyes of interventional cardiologists, nurses, and age- and sex-matched unexposed controls were screened by dilated slit lamp examination and posterior lens changes graded using a modified Merriam-Focht technique. Individual cumulative lens X-ray exposure was calculated from responses to a questionnaire and personal interview.
Results – The prevalence of radiation-associated posterior lens opacities was 52% (29/56, 95% CI: 35-73) for interventional cardiologists, 45% (5/11, 95% CI: 15-100) for nurses, and 9% (2/22, 95% CI: 1-33) for controls. Relative risks of lens opacity was 5.7 (95% CI: 1.5-22) for interventional cardiologists and 5.0 (95% CI: 1.2-21) for nurses. Estimated cumulative ocular doses ranged from 0.01 to 43 Gy with mean and median values of 3.4 and 1.0 Gy, respectively. A strong dose-response relationship was found between occupational exposure and the prevalence of radiation-associated posterior lens changes.
Conclusions – These findings demonstrate a dose dependent increased risk of posterior lens opacities for interventional cardiologists and nurses when radiation protection tools are not used. While study of a larger cohort is needed to confirm these findings, the results suggest ocular radio-protection should be utilized.
Ciraj-Bjelac O, Rehani MM, Sim KH, Liew HB, Vano E, Kleiman NJ. Risk for radiation-induced cataract for staff in interventional cardiology: Is there reason for concern? Catheterization and Cardiovascular Interventions. 2010;76(6):826-834. doi: 10.1002/ccd.22670
2009
Radiation Cataractogenesis: A Review of Recent Studies
The lens of the eye is recognized as one of the most radiosensitive tissues in the human body, and it is known that cataracts can be induced by acute doses of less than 2 Gy of low-LET ionizing radiation and less than 5 Gy of protracted radiation. Although much work has been carried out in this area, the exact mechanisms of radiation cataractogenesis are still not fully understood. In particular, the question of the threshold dose for cataract development is not resolved. Cataracts have been classified as a deterministic effect of radiation exposure with a threshold of approximately 2 Gy. Here we review the combined results of recent mechanistic and human studies regarding induction of cataracts by ionizing radiation. These studies indicate that the threshold for cataract development is certainly less than was previously estimated, of the order of 0.5 Gy, or that radiation cataractogenesis may in fact be more accurately described by a linear, no-threshold model.
Ainsbury EA, Bouffler SD, Dörr W, et al. Radiation Cataractogenesis: A Review of Recent Studies. Radiation Research. 2009;172(1):1-9. doi: 10.1667/RR1688.1