Occupational Dose Research Articles

EVALUATION OF ANNUAL RADIATION EXPOSURE OF STAFF IN A CARDIAC CATHETERIZATION DEPARTMENT IN SAUDI ARABIA

The objective of this study is to estimate the annual effective dose for cardiologists and nurses by measuring Hp(10) and Hp(0.07) during cardiac catheterization procedures. A total of 16 staffs members were working in interventional cardiology during 1year at a tertiary hospital. The occupational dose was measured using calibrated thermo-luminescent dosemeters (TLD-100, LiF:Mg,Ti). The overall mean and range of the annual Hp(10) and Hp(0.07) (mSv) for cardiologists were 3.7 (0.13-14.5) and 3.2 (0.21-14.7), respectively. Cardiologists were frequently exposed to higher doses compared with nurses and technologists. The exposure showed wide variations, which depend on occupation and workload. Staff is adhered to radiation protection guidelines regarding shielding the trunk, thyroid shield, thus appropriately protected. Lens dose measurement is recommended to ensure that dose limit is not exceeded.

Occupational exposure and radiobiological risk from thyroid radioiodine therapy in Saudi Arabia

Worldwide, thyroid cancer accounts for some 10% of total cancer incidence, most markedly for females. Thyroid cancer radiotherapy, typically using 131I (T1/2 8.02 days; β− max energy 606 keV, branching ratio 89.9%), is widely adopted as an adjunct to surgery or to treat inoperable cancer and hyperthyroidism. With staff potentially receiving significant doses during source preparation and administration, radiation protection and safety assessment are required in ensuring practice complies with international guidelines. The present study, concerning a total of 206 patient radioiodine therapies carried out at King Faisal Specialist Hospital and Research Center over a 6-month period, seeks to evaluate patient and occupational exposures during hospitalization, measuring ambient doses and estimating radiation risk. Using calibrated survey meters, patient exposure dose-rate estimates were obtained at a distance of 30-, 100- and 300 cm from the neck region of each patient. Occupational and ambient doses were measured using calibrated thermoluminescent dosimeters. The mean and range of administered activity (AA, in MBq) for the thyroid cancer and hyperthyroidism treatment groups were 4244 ± 2021 (1669–8066), 1507.9 ± 324.1 (977.9–1836.9), respectively. The mean annual occupational doses were 1.2 mSv, that for ambient doses outside of the isolation room corridors were found to be 0.2 mSv, while ambient doses at the nursing station were below the lower limit of detection. Exposures to staff from patients being treated for thyroid cancer were less compared to hyperthyroidism patients. With a well-defined protocol, also complying with international safety requirements, occupational exposures were found to be relatively high, greater than most reported in previous studies.

Experimental Assessment of Workplace Radiation Exposure in Diagnostic X-ray Medical Imaging Centres in Benin from 2019 to 2020.

The ease of prescribing radiological examinations has prompted an expansion in radiological procedures and, consequently, an increase of occupational dose to medical imaging workers. However, little is known about radiation exposure in the workplace of medical radiology professionals in many countries, and in Benin particularly. The purpose of this study was to assess ambient radiation doses in diagnostic X-ray medical facilities in Benin and to observe whether exposure levels are below reference levels. A total of 72 public and private medical imaging centres participated in a cross-sectional study carried out from June 2019 to February 2020 in Benin. These centres had 59 X-ray, four chest and six computed tomography (CT) scan rooms. A calibrated radiameter able to measure short, pulsed or continuous X fields and gamma/beta (50 nSv to 10 Sv) was used to measure exposure levels in these functional rooms. Scattered X-ray doses and exposure time from radiological examinations both behind the lead glass of the control area to assess the levels of exposure of professionals and outside of the examination room to evaluate the level of exposure of the public (including non-exposed workers) have been provided. Equivalent doses estimated per hour were compared with the reference levels of 7.50 and 0.05 µSv per hour for workers and the public, respectively. At the control area, the mean/median (min-max) equivalent doses were 0.09/0.07 (0.00-0.21), 2.39/0.13 (0.00-75.67), and 228.39/28.65 (0.39-869.75) µSv per hour for the chest, X-ray, and CT-scan rooms, respectively. Among 69 examination rooms, 13.04% of the equivalent dose estimated in the workplace behind the lead glass was greater than 7.50 µSv per hour; 65 out of 69 examination rooms showed that 40.00% of the equivalent dose estimated behind the doors was greater than 0.05 µSv per hour. These results demonstrated that current controls, including leaded glass separating the control panel and leaded doors between the examination room and the corridor, are inadequate to limit radiation exposures. The controls must be upgraded and a dosimetry program should be implemented to monitor exposures of employees, patients, and visitors.

Estimation of patients organ doses and staff exposure during bone scan examination

Radiopharmaceuticals are utilized in diagnostic nuclear medicine (NM) for a wide range of disorders. The purposes of the work are to assess patient organ doses in bone scan procedure with 99 m Tc-Methyl diphosphonate (MDP) and quantify the NM technologist exposure during bone scan procedure. Staff radiation exposure was determined using thermo-luminescent dosimeters (TLDs, Type LiF: Mg, Cu, P (GR200A)) were placed at the dominant hand. The TLD was calibrated to estimate the personal equivalent dose Hp (10) and Hp (0.07). The mean and range of the annual personal dose equivalent (Hp (10) and Hp (0.07) mSv) were 7.6 (3.2–9.1) and 30 (17.2–44), respectively. The patients' bladder retains an insignificant amount of the administered activity. Vast differences in patients’ and occupational doses were detected. Increasing staff awareness about radiation safety is recommended to enhance radiation protection and education unnecessary radiation doses. The personal doses equivalent are within the acceptable annual determined limits.

A Cross-sectional Study Based on the Assessment of the Radiation dose for Medical Radiation Workers

Background: A monitoring for radiological technologists and radiation workers must be implemented to ensure the radiation safety. Aims: The aim of our study was to measure the occupational radiation dose for medical workers from the Department of Diagnostic Radiology, Cardiac Catheterization Laboratory, Nuclear Medicine, Dental Services, Endoscopy, and Surgery at King Abdulaziz Medical City (KAMC), Riyadh, Saudi Arabia. Materials & Methods: This study was conducted at KAMC, Ministry of National Guard-Health Affairs, Riyadh, Saudi Arabia. Across-sectional study and a suitably and structured questionnaire was adapted from the previous similar studies and monitored radiation doses designed in line with the study's objectives were collected among the different medical workers. A total of 223 medical radiation workers were involved in this study, and descriptive statistics were used to analyze the data. Results: It is noted that the diagnostic radiology department recorded the highest value of effective dose followed by cardiac catheterization laboratory and nuclear medicine and so on. The measured amount of effective dose for diagnostic radiology, cardiac catheterization laboratory, nuclear medicine, dental services, endoscopy, and surgery at KAMC was found to be 14.35, 5.23, 4.56, 3.88, 3.52, and 1.87 mSv, respectively. Conclusions: This study provide an evidence that the occupational radiation dose for all the monitored departments at KAMC are well below the international recommended dose limit (20 mSv).

Occupational and Patient Radiation Dose and Quality Implications of Femoral Access Imaging During Coronary Angiography.

PurposeCardiologists often perform angiography of the common femoral artery (CFA) access site to evaluate whether the anatomy is suitable for deployment of a vascular closure device or to assess whether iatrogenic vessel damage has occurred. The choice of acquisition mode has radiation dose implications. The objective of this study was to investigate the influence of the selected type of CFA x-ray imaging mode (fluoro save, cine acquisition and digital subtraction angiography (DSA)) and tube angle on patient and staff dose during coronary angiography.Materials and MethodsAssessment of image quality for the different modes was performed to determine whether lower dose modes provide images of sufficient clinical quality to be routinely employed. Radiation dose levels for the patients (n=782), cardiologists (n=17), scrub nurses (n=27) and scout nurses (n=32) were measured in a prospective single-centre study between February 2017 and August 2019. Three Philips angiographic units and DoseAware dose monitoring systems were used.ResultsAmong the acquisition modes, fluoro save provided acceptable diagnostic quality for visualizing femoral access points and diagnosing pathology in 99% of cases. Average patient dose area product (DAP) was 83.95, 742.50, and 3363.41mGy2 and average patient air kerma (AK) was 0.87, 8.44, and 18.61mGy for fluoro save, cine, and DSA acquisitions, respectively. The use of higher dose imaging modes, imaging in the contralateral view and utilizing steeper TA was associated with a higher patient dose. Due to staff dose being highly correlated with DAP and AK, it was difficult to observe any association between staff dose and CFA imaging mode. However, this does not discount a potential increase in occupational dose due to the use of cine angiography or digital subtraction angiography during CFA imaging.ConclusionDSA of the CFA should be avoided during transfemoral coronary angiography unless critical to diagnostic analysis. It is recommended that fluoroscopic operators consider utilizing lower dose modes in the ipsilateral orientation ≤32° TA to reduce the risk of patient and staff radiation exposure.

Recommendations for the use of active personal dosemeters (APDs) in interventional workplaces in hospitals.

Occupational radiation doses from interventional procedures have the potential to be relatively high. The requirement to optimise these doses encourages the use of electronic or active personal dosimeters (APDs) which are now increasingly used in hospitals. They are typically used in tandem with a routine passive dosimetry monitoring programme, with APDs used for real-time readings, for training purposes and when new imaging technology is introduced. However, there are limitations when using APDs. A survey in hospitals to identify issues related to the use of APDs was recently completed, along with an extensive series of APD tests by the EURADOS Working Group 12 on Dosimetry for Medical Imaging. The aim of this review paper is to summarise the state of the art regarding the use of APDs. We also used the results of our survey and our tests to develop a set of recommendations for the use of APDs in the clinical interventional radiology/cardiology settings, and draw attention to some of the current challenges.

Comparison of operator and patient radiation exposure during fluoroscopy-guided vertebroplasty and kyphoplasty: a systematic review and meta-analysis.

Percutaneous vertebroplasty (PV) and balloon kyphoplasty (BK) are two minimally invasive techniques used to treat mechanical pain secondary to spinal compression fractures. A concern for both procedures is the radiation exposure incurred by both operators and patients. The authors conducted a systematic review of the available literature to examine differences in interventionalist radiation exposure between PV and BK and differences in patient radiation exposure between PV and BK. The authors conducted a search of the PubMed, Ovid Medline, Cochrane Reviews, Embase, and Web of Science databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Full-text articles in English describing one of the primary endpoints in ≥ 5 unique patients treated with PV or BK of the mobile spine were included. Estimates of mean operative time, radiation exposure, and fluoroscopy duration were reported as weighted averages. Additionally, annual occupational dose limits provided by the United States Nuclear Regulatory Commission (USNRC) were used to determine the number needed to harm (NNH). The meta-analysis included 27 articles. For PV, the mean fluoroscopy times were 4.9 ± 3.3 minutes per level without protective measures and 5.2 ± 3.4 minutes with protective measures. The mean operator radiation exposures per level in mrem were 4.6 ± 5.4 at the eye, 7.8 ± 8.7 at the neck, 22.7 ± 62.4 at the torso, and 49.2 ± 62.2 at the hand without protective equipment and 0.3 ± 0.1 at the torso and 95.5 ± 162.5 at the hand with protection. The mean fluoroscopy times per level for BK were 6.1 ± 2.5 minutes without protective measures and 6.0 ± 3.2 minutes with such measures. The mean exposures were 31.3 ± 39.3, 19.7 ± 4.6, 31.8 ± 34.2, and 174.4 ± 117.3 mrem at the eye, neck, torso, and hand, respectively, without protection, and 1, 9.2 ± 26.2, and 187.7 ± 100.4 mrem at the neck, torso, and hand, respectively, with protective equipment. For protected procedures, radiation to the hand was the limiting factor and the NNH estimates were 524 ± 891 and 266 ± 142 for PV and BK, respectively. Patient exposure as measured by flank-mounted dosimeters, entrance skin dose, and dose area product demonstrated lower exposure with PV than BK (p < 0.01). Operator radiation exposure is significantly decreased by the use of protective equipment. Radiation exposure to both the operator and patient is lower for PV than BK. NNH estimates suggest that radiation to the hand limits the number of procedures an operator can safely perform. In particular, radiation to the hand limits PV to 524 and BK to 266 procedures per year before surpassing the threshold set by the USNRC.

Trends in Occupational Radiation Doses for U.S. Radiologic Technologists Performing General Radiologic and Nuclear Medicine Procedures, 1980-2015.

Background Occupational doses to most medical radiation workers have declined substantially since the 1950s because of improvements in radiation protection practices. However, different patterns may have emerged for radiologic technologists working with nuclear medicine because of the higher per-procedure doses and increasing workloads. Purpose To summarize annual occupational doses during a 36-year period for a large cohort of U.S. radiologic technologists and to compare dose between general radiologic technologists and those specializing in nuclear medicine procedures. Materials and Methods Annual personal dose equivalents (referred to as doses) from 1980 to 2015 were summarized for 58 434 (62%) participants in the U.S. Radiologic Technologists (USRT) cohort who responded to the most recent mailed work history survey (years 2012-2014) and reported never regularly performing interventional procedures. Doses were partitioned according to the performance of nuclear medicine (yes or no, frequency, procedure type) by calendar year. Annual dose records were described by using summary statistics (eg, median and 25th and 75th percentiles). Results Median annual doses related to performance of general radiologic procedures decreased from 0.60 mSv (interquartile range [IQR], 0.10-1.9 mSv) in 1980 to levels below the limits of detection by 2015, whereas annual doses related to performance of nuclear medicine procedures remained relatively high during this period (median, 1.2 mSv; IQR, 0.12-3.0 mSv). Higher median annual doses were associated with more frequent (above vs below the median) performance of diagnostic nuclear medicine procedures (≥35 vs <35 times per week; 1.6 mSv [IQR, 0.30-3.3 mSv] and 0.9 mSv [IQR, 0.10-2.6 mSv]). Higher and more variable annual doses were associated with more frequent performance of cardiac nuclear medicine (≥10 times per week) and PET (nine or more times per week) examinations (median, 1.6 mSv [IQR, 0.30-2.2 mSv] and 2.2 mSv [IQR, 0.10-4.6 mSv], respectively). Conclusion Annual doses to U.S. radiologic technologists performing general radiologic procedures declined during a 36-year period. However, consistently higher and more variable doses were associated with the performance of nuclear medicine procedures, particularly cardiac nuclear medicine and PET procedures. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Mettler and Guiberteau in this issue.

THE POTENTIAL TO USE TLD MEASUREMENTS TO VALIDATE THE OCCUPATIONAL RADIATION PROTECTION AT THE DEPARTMENT OF NUCLEAR MEDICINE.

Diagnostic examinations in nuclear medicine increase. This can cause a higher radiation burden to the personnel. The aim of this study was to create and apply a method to validate the occupational radiation protection at the Department of Nuclear Medicine using thermoluminescence dosemeters (TLD). Occupational doses in- and outside of the department and the dose rate distribution around the positron emission tomography/computed tomography (PET/CT) were validated in terms of Hp(10) using TLD-100. Backscatter correction factors were estimated to implement the TLD measurements on different materials. After correction for backscatter, the result indicates that doses in- and outside of the department are below recommended values and dose limits. The highest and the lowest dose rate were measured beside the 18F-autoinjector and the PET/CT gantry, respectively. The method of using TLD gives a good estimate of how the occupational radiation protection performs at the Department of Nuclear Medicine and can thus help in the optimization of radiation protection.

The National Dose Registry—Canadian occupational exposure to ionising radiation, 1998–2018

The National Dose Registry (NDR) is owned and operated independently by Health Canada. This paper provides an overview of how the registry operates within the Canadian regulatory structure, followed by an analysis of annual effective dose trends in nine job classes with relatively higher mean annual effective doses, i.e. greater than 1 mSv as reported in 2017. The analysis showed that, with a few exceptions, mean annual effective doses have generally decreased or remained practically unchanged in the past two decades at relatively low exposure levels. This review of occupational dose trends is evidence of the effectiveness of radiation protection programmes in Canada. The NDR has played an important role in the identification of relatively higher dose records and allowed the regulatory bodies to act immediately to ensure appropriate actions were taken.

Occupational Radiation Dose, Especially for Eye Lens: Hp(3), in Medical Staff Members Involved in Computed Tomography Examinations

Radiation dose management of medical staff has become increasingly important. Particularly, based on the statement by the International Commission on Radiological Protection (ICRP) in 2011, a new lower equivalent dose limit for the eye lens is being established in each country. Although many reports have discussed the occupational radiation dose in interventional radiology (IR), few studies have examined the dose during computed tomography (CT) examinations. This study investigated the radiation dose exposure to medical staff present in the CT room during irradiation, with particular focus on the exposure to eye lens. The radiation dose exposure to those who assist patients during head, chest and upper abdomen CT examination was measured in a phantom study. The radiation dose exposure with scattered radiation was never negligible (i.e., high); Hp(3) was the highest in head CT examination, at 0.44 mSv per examination. Furthermore, the shielding effect of radiation protection glasses was large, and radiation protection glasses are useful tools for the medical staff who are involved in CT examinations. The justification and optimisation should be carefully considered in assistant actions.

Radiation-Induced Lens Opacity and Cataractogenesis: A Lifetime Study Using Mice of Varying Genetic Backgrounds.

Recent epidemiological findings and reanalysis of historical data suggest lens opacities resulting from ionizing radiation exposures are likely induced at lower doses than previously thought. These observations have led to ICRP recommendations for a reduction in the occupational dose limits for the eye lens, as well as subsequent implementation in EU member states. The EU CONCERT LDLensRad project was initiated to further understand the effects of ionizing radiation on the lens and identify the mechanism(s) involved in radiation-induced cataract, as well as the impact of dose and dose-rate. Here, we present the results of a long-term study of changes to lens opacity in male and female adult mice from a variety of different genetic (radiosensitive or radioresistant) backgrounds, including mutant strains Ercc2 and Ptch1, which were assumed to be susceptible to radiation-induced lens opacities. Mice received 0.5, 1 and 2 Gy 60Co gamma-ray irradiation at dose rates of 0.063 and 0.3 Gy min-1. Scheimpflug imaging was used to quantify lens opacification as an early indicator of cataract, with monthly observations taken postirradiation for an 18-month period in all strains apart from 129S2, which were observed for 12 months. Opacification of the lens was found to increase with time postirradiation (with age) for most mouse models, with ionizing radiation exposure increasing opacities further. Sex, dose, dose rate and genetic background were all found to be significant contributors to opacification; however, significant interactions were identified, which meant that the impact of these factors was strain dependent. Mean lens density increased with higher dose and dose rate in the presence of Ercc2 and Ptch1 mutations. This project was the first to focus on low (<1 Gy) dose, multiple dose rate, sex and strain effects in lens opacification, and clearly demonstrates the importance of these experimental factors in radiobiological investigations on the lens. The results provide insight into the effects of ionizing radiation on the lens as well as the need for further work in this area to underpin appropriate radiation protection legislation and guidance.

Students' and Qualified Radiographers' Perspectives and Understanding on Occupational Dose Monitoring and Prevention Strategies.

Effective implementation and ongoing monitoring of occupational radiation safety and protection is key for radiographers as prolonged exposure to ionizing radiation can increase the risk of long-term ill health effects. It is important that radiographers are aware of what is required of them to remain within the permitted dose limit. Topics and training on dose monitoring and occupational practice safety and practice are embedded in both undergraduate and postgraduate courses and ongoing as part of continuous professional development. However, whether these are accurately, effectively implemented and adhered too in practice needs to be monitored. This study aimed to investigate students and radiographers' awareness, observations, and understandings of their compliance to occupational radiation safety and protection and monitoring thereof in the clinical setting. A cross sectional survey design with a questionnaire consisting of closed and open-ended items were used. The data were analysed with the use of SPSS statistical software tool. The response rates for student radiographers were 62% and qualified radiographers 23.19%. Most participants indicated that they were knowledgeable on best practice methods regarding radiation protection and safety. However, regarding the importance of personal monitoring devices, the responses varied and there were some inconsistencies. The perspectives of participants on rotating through different imaging examination types revealed that of least importance was the occupational exposure. Students were focused as part of their training on acquiring the necessary skills to conduct imaging examinations. Qualified radiographers focused on upkeeping their skills when it came to their rotation between the general and specialized imaging examinations. To overcome some of these inconsistencies it is recommended that standardized practice guidelines be reviewed by both the academic institution and the clinical training sites enforcing the importance of dose monitoring and radiation safety and best practice principles.

Occupational dose measurement for radiographers during cardiac catheterization procedures

Occupational dose measurement for radiographers during cardiac catheterization procedures

Occupational radiation dose for medical workers at the University Hospital Center “Mother Theresa” in Tirana

The exposure to environmental and “artificial” radiation sources was investigated in the University Hospital Center “Mother Theresa” in Tirana. The concentration of indoor radon exceeds the reference level of 300 Bq m−3 in some 50% of workplaces, accounting for an average effective dose rate of 3.7 mSv y−1. The average dose rate due to external gamma radiation was measured to be 0.12 mSv y−1. While, the occupational exposure of medical workers was found to be 0.67 mSv y−1 on average. The high radon concentrations account for approximately 83% of worker radiation dose, indicating the need for adopting mitigation actions.

Assessment of Hp(10) and Hp(0.07) doses for cardiac catheterization personnel: A 5-year retrospective study

This study estimates the mean annual occupational dose of Hp(0.07) and Hp(10) for cardiac catheterization personnel in Saudi Arabia. A retrospective analysis was conducted for 875 workers to estimate both the Hp(0.07) and Hp(10) radiation dose values using thermoluminescent dosimeters (TLDs) from 2015 to 2019. The workers were divided into 10 medical centers around the country. They consisted of cardiologists, radiologists, anesthesiologists, nurses, medical students, and medical assistants. The mean annual Hp(10) and Hp(0.07) radiation dose over the 5-year study period were 0.95 ± 0.02 mSv (range, 0.09–4.51 mSv) and 0.93 ± 0.02 mSv (range, 0.07–4.38 mSv), respectively. No single dose exceeded the International Commission on Radiological Protection dose limits. More than 94% of the workers received Hp(10) and Hp(0.07) radiation doses of less than 2 mSv. The results revealed that no statistically significant differences in Hp (0.07) (F (9,327.8) = 1.05; p = 0.391) and Hp(10) (F (9,865) = 1.60; p = 0.11) doses among the workers in the centers. The Hp(10) and Hp(0.07) values for catheterization laboratory (cath-lab) workers in this study imply that cath-labs are a safe environment in terms of occupational radiation protection. This is due to high personnel awareness of the importance of applying the “as low as reasonably achievable” principle. Yet, it is strongly recommended that cath-lab workers take every reasonable approach to keep their radiation exposure as low as practically achievable.

Assessment of the occupational dose and radiogenic risk in diagnostic radiology and nuclear medicine examinations

Assessment of the occupational dose and radiogenic risk in diagnostic radiology and nuclear medicine examinations

Assessment of the occupational dose and radiogenic risk in diagnostic radiology and nuclear medicine examinations

Assessment of the occupational dose and radiogenic risk in diagnostic radiology and nuclear medicine examinations

Get Protected! Recommendations for Staff in IR.

PurposeEvaluation and registration of patient and staff doses are mandatory under the current European legislation, and the occupational dose limits recommended by the ICRP have been adopted by most of the countries in the world.MethodsRelevant documents and guidelines published by international organisations and interventional radiology societies are referred. Any potential reduction of patient and staff doses should be compatible with the clinical outcomes of the procedures.ResultsThe review summarises the most common protective measures and the needed quality control for them, the criteria to select the appropriate protection devices, and how to avoid unnecessary occupational radiation exposures. Moreover, the current and future advancements in personnel radiation protection using medical simulation with virtual and augmented reality, robotics, and artificial intelligence (AI) are commented. A section on the personnel radiation protection in the era of COVID-19 is introduced, showing the expanding role of the interventional radiology during the pandemic.ConclusionThe review is completed with a summary of the main factors to be considered in the selection of the appropriate radiation protection tools and practical advices to improve the protection of the staff.