Staff Doses in Interventional Radiology: A National Survey

Technical note: A comparison of physician doses in C-Arm and CT fluoroscopy procedures

PURPOSE

We address the misconception that the typical physician dose is higher for CT fluoroscopy (CTF) procedures compared to C-Arm procedures.

METHODS

We compare physician scatter doses using two methods: a literature review of reported doses and a model based on a modified form of the dose area product (DAP). We define this modified form of DAP, "cumulative absorbed DAP," as the product of the area of the x-ray beam striking the patient, the dose rate per unit area, and the exposure time.

RESULTS

The patient entrance dose rate for C-Arm fluoroscopy (0.2 mGy/s) was found to be 15 times lower than for CT fluoroscopy (3 mGy/s). A typical beam entrance area for C-Arm fluoroscopy reported in the literature was found to be 10.6 × 10.6 cm (112 cm2), whereas for CTF was 0.75 × 32 cm (24 cm2). The absorbed DAP rate for C-Arm fluoroscopy (22 mGy*cm2/s) was found to be 3.3 times lower than for CTF (72 mGy*cm2/s). The mean fluoroscopy time for C-Arm procedures (710 s) was found to be 21 times higher than for CT fluoroscopy procedures (23 s). The cumulative absorbed DAP for C-Arm procedures was found to be 9.4 times higher when compared to CT procedures (1.59 mGy*m2 vs. 0.17 mGy*m2).

CONCLUSIONS

The higher fluoroscopy time in C-Arm procedures leads to a much lower cumulative DAP (i.e., physician scatter dose) in CTF procedures. This result can inform interventional physicians deciding on whether to perform inter-procedural imaging inside the room as opposed to retreating from the room.

Radiation shielding assessment for interventional radiology personnel: Geant4 dosimetry of lead-free compositions

The inherent biological hazards associated with ionizing radiation necessitate the implementation of effective shielding measures, particularly in medical applications. Interventional radiology, in particular, poses a unique challenge as it often exposes medical personnel to prolonged periods of high x-ray doses. Historically, lead and lead-based compounds have been the primary materials employed for shielding against photons. However, the drawbacks of lead, including its substantial weight causing personnel's inflexibility and its toxicity, have raised concerns regarding its long-term impact on both human health and the environment. Barium tantalate has emerged as a promising alternative, due to its unique attenuation properties against low-energy x-rays, specifically targeting the weak absorption area of lead. In the present study, we employ the Geant4 Monte Carlo simulation tool to investigate various formulations of barium tantalate doped with rare earth elements. The aim is to identify the optimal composition for shielding x-rays in the context of interventional radiology. To achieve this, we employ a reference x-ray spectrum typical of interventional radiology procedures, with energies extending up to 90 keV, within a carefully designed simulation setup. Our primary performance indicator is the reduction in air kerma transmission. Furthermore, we assess the absorbed doses to critical organs at risk within a standard human body phantom protected by the shield. Our results demonstrate that specific concentrations of the examined rare earth impurities can enhance the shielding performance of barium tantalate. To mitigate x-ray exposure in interventional radiology, our analysis reveals that the most effective shielding performance is achieved when using barium tantalate compositions containing 15% Erbium or 10% Samarium by weight. These findings suggest the possibility of developing lead-free shielding solutions or apron for interventional radiology personnel, offering a remarkable reduction in weight (exceeding 30%) while maintaining shielding performance at levels comparable to traditional lead-based materials.

A Prototype Software System for Intra-procedural Staff Dose Monitoring and Virtual Reality Training for Fluoroscopically Guided Interventional Procedures

Staff dose management in fluoroscopically guided interventional procedures is a continuing problem. The scattered radiation display system (SDS), which our group has developed, provides in-room visual feedback of scatter dose to staff members during fluoroscopically guided interventional (FGI) procedures as well as extra-procedure staff and resident training. There have been a number of virtual safety training systems developed that provide detailed feedback for staff, but utilize expensive graphics processing units (GPUs) and dosimeter systems, or interaction with the x-ray system in a manner which entails additional radiation exposure and is not compatible with the As Low as Reasonably Achievable paradigm. The SDS, on the other hand, incorporates a library of look-up-table (LUT) room scatter distributions determined using the EGSnrc Monte Carlo software, which facilitates accurate and rapid system update without the need for GPUs. Real-time display of these distributions is provided for feedback to staff during a procedure. After a procedure is completed, machine parameter and staff position log files are stored, retaining all of the exposure and geometric information for future review. A graphic user interface (GUI) in Unity3D enables procedure playback and interactive virtual-reality (VR) staff and resident training with virtual control of exposure conditions using an Oculus headset and controller. Improved staff and resident awareness using this system should lead to increased safety and reduced occupational dose.

What happened when medical staff in Beijing, China wore over-apron dosemeters?

The wearing method of personal dosemeters for medical staff changed from under to outside the operator's protective apron in April 2020. We measured the radiation dose Hp(10) for medical staff in Beijing from September 2020 to October 2021. The study population consisted of 3291 medical staff. All participants were divided into three groups. After excluding unusually low doses, the collected data higher than the detection limit involved 811 (7.8%) of 10 395 readings from 479 (14.6%) of 3291 staff. The mean equivalent dose was 1.4 mSv/3 months, with an SD of 2.3 mSv. The calculated average annual effective doses of radiation workers in the three groups after the interventional procedures from September 2020 to October 2021 ranged from 0.47 to 0.63 mSv/year, with median values of 0.32, 0.23 and 0.26 mSv/year, respectively.

Medical personnel occupationally exposed to low-dose ionising radiation in Federation of Bosnia and Herzegovina: A cytogenetic study

Medical radiation exposures have been reduced significantly with modern equipment and protection measures. Biomonitoring of medical personnel can provide information concerning possible effects of radiation exposure. However, chromosome aberration (CA) analysis is now recommended only when the estimated effective dose is 200 mSv or higher. In this retrospective study in Bosnia and Herzegovina, we have measured the cytogenetic status of medical workers and healthy volunteers (controls). Peripheral blood samples from 66 medical workers exposed to low-dose ionising radiation and 89 non-exposed volunteers were collected for chromosome aberrations (CA) analysis and the cytokinesis-block micronucleus (CBMN) assay. Higher rates of chromatid and chromosome breaks, acentric fragments, double minutes, micronuclei, and micronucleated binuclear cells were observed in the control group, while the rate of nucleoplasmic bridges was higher in the medical workers group.

Radiation Protection of the Eye Lens in Fluoroscopy-guided Interventional Procedures

The medical staff involved in fluoroscopy-guided procedures are at potential risks of radiation-induced cataract. Therefore, proper monitoring of the lens doses is critical, and radiation protection should be provided to the maximum extent that is reasonably achievable. The collar dosimeter is necessary to avoid underestimation of the lens dose, and the third dosimeter behind the protective eyewear would be helpful for those who are likely to exceed the dose limit. The reduction of the patient doses will correspondingly reduce the staff doses. Proper placement of the ceiling-mounted shields and minimization of the face-to-glass gap are the keys to effective shielding. The optimization of procedures and devices that help maintain a distance from the irradiated area and to prevent the looking-up posture will substantially reduce the lens dose.

Safety During Ureteroscopy: Radiation, Eyes, and Ergonomics

It is known that urologic surgeons are at risk of work-place injury due to the physical requirements of operating and exposure to hazards. These hazards include radiation, exposure to body fluids, use of laser energy, and orthopedic injury due to the physical nature of operating. The risks that these hazards present can be mitigated by implementing several evidence-based safety measures. The methods to protect against radiation exposure include keeping radiation usage in the operating room as low as reasonably achievable, donning lead aprons, and wearing protective glasses. Additionally, protective glasses decrease the risk of eye injury from laser injury and exposure to body fluids. Finally, practicing sound surgical ergonomics is essential to minimize the risk of orthopedic injury and promote career longevity. The interventions discussed herein are simple and easy to implement in one's daily practice of urology.

Occupational radiation exposure to the lens of the eye in interventional radiology

INTRODUCTION

Cataract formation is a tissue reaction effected by radiation exposure. The purpose of this study was to evaluate the occupational exposure to the lens of the eye of interventional radiologists (IR's) and interventional radiology staff, with and without lead glasses.

METHODS

Ethical approval was provided by the hospital research and ethics committee. A prospective cohort study was performed over 1 year, doses recorded, lifetime dose (estimated at working 5 days in angiography, for 30 years) was estimated and dose compared to current guidelines. Thermoluminescent dosimeters (TLDs; Landauer, Glenwood, USA) Hp(3) were placed on both the exterior and interior side of the personal lead glasses worn by three interventional radiologists and two radiographers. They were monitored during all procedures performed within 1 year. Lead glasses (AttenuTech^® Microlite^® , Florida, USA) with specifications were 0.75 mm lead equivalent front shield, and Side shield 0.3 mm Pb equivalent. A control TLD was placed in the storage location of the lead glasses when not in use. Yearly dose was measured and lifetime dose was calculated from the data obtained. Calculation of dose received per day(s) spent performing procedures for both annual and lifetime exposure was performed. In addition a record of occurrence of splashes on glasses was made after each case.

RESULTS

Eye doses without protection were double the recommended limits for both annual and lifetime dose. For interventional radiologists working between 3 and 4 or more days in the lab per week, annual dose thresholds would be exceeded (20 mSv/year averaged over 5 years, no more than 50 mSv in 1 year). If interventional radiologists worked between 3 and 4 or more days in the lab, lifetime dose thresholds would be exceeded (500 mSv lifetime dose). Lead glasses reduced radiation exposure by an average of 79%. If lead glasses were worn no interventional radiologists would exceed annual or lifetime dose thresholds to the eyes even if working 5 days per week as the primary operator. Radiographers would not exceed annual or lifetime dose thresholds even without lead glasses. Splash incidents occurred for all interventional radiologists and one radiographer.

CONCLUSION

The use of lead glasses even in this small study resulted in a decreased dose of radiation to the lens of the eye. Regular use of radiation protection eyewear will reduce eye dose for primary proceduralists to well below yearly and lifetime thresholds.

Review of personal radiation exposure dose and history of the interventional procedure records for 40 years

Objective

To inspect personal dose as an interventional radiologist for 40 years, to assess the enforcement number of interventional radiology (IR), and to check for radiation cataract.

Materials and methods

I evaluated my own effective dose, an equivalent dose to the lens of the eye (EDL), and the number of IR procedures between March 2019 and June 1979. I examined the lens in June 2019 as a radiologist for 40 years.

Results

The accumulation dose was 0 mSv in 1979–88. During 1989–93, the right crystalline lens equivalence of the value dose was measured. During 1993–96, two badge items for the head, neck, and abdomen were present. Both were distributed, but attaching to the same part and reversing occurred frequently. The EDL of the recent 5 years has exceeded 100 mSv. No association with the number of IR procedures was recognized. Posterior subcapsular vacuoles (PSV) as the early changes of the radiation cataract were recognized as four on the left and one on the right.

Conclusion

It is important to get accustomed to film badge wearing, and the cancelation of making a mistake in the wearing part. Radiologists should check the PSV at a stage beyond a certain constant dose.

Fast Monte Carlo codes for occupational dosimetry in interventional radiology

PURPOSE

Interventional radiology techniques cause radiation exposure both to patient and personnel. The radiation dose to the operator is usually measured with dosimeters located at specific points above or below the lead aprons. The aim of this study is to develop and validate two fast Monte Carlo (MC) codes for radiation transport in order to improve the assessment of individual doses in interventional radiology. The proposed methodology reduces the number of required dosemeters and provides immediate dose results.

METHODS

Two fast MC simulation codes, PENELOPE/penEasyIR and MCGPU-IR, have been developed. Both codes have been validated by comparing fast MC calculations with the multipurpose PENELOPE MC code and with measurements during a realistic interventional procedure.

RESULTS

The new codes were tested with a computation time of about 120 s to estimate operator doses while a standard simulation needs several days to obtain similar uncertainties. When compared with the standard calculation in simple set-ups, MCGPU-IR tends to underestimate doses (up to 5%), while PENELOPE/penEasyIR overestimates them (up to 18%). When comparing both fast MC codes with experimental values in realistic set-ups, differences are within 25%. These differences are within accepted uncertainties in individual monitoring.

CONCLUSION

The study highlights the fact that computational dosimetry based on the use of fast MC codes can provide good estimates of the personal dose equivalent and overcome some of the limitations of occupational monitoring in interventional radiology. Notably, MCGPU-IR calculates both organ doses and effective dose, providing a better estimate of radiation risk.

Interventional radiologists have a higher rate of chromosomal damage due to occupational radiation exposure: a dicentric chromosome assay

OBJECTIVES

There are growing concerns regarding radiation exposure in medical workers who perform interventional fluoroscopy procedures. Owing to the nature of certain interventional procedures, workers may be subjected to partial-body radiation exposure that is high enough to cause local damage. We aimed to investigate the level of radiation exposure in interventional radiologists in South Korea by performing cytogenetic biodosimetry, particularly focusing on partial-body exposure.

METHODS

Interventional radiologists (n = 52) completed a questionnaire, providing information about their work history and practices. Blood samples were collected and processed for a dicentric chromosome assay. We determined Papworth's U-value to assess the conformity of dicentrics with the Poisson distribution to estimate the partial-body exposures of the radiologists.

RESULTS

Radiologists had a higher number of dicentrics than the normal population and industrial radiographers. Indeed, subjects with a U-value of > 1.96, an indicator of heterogeneous exposure, were observed more frequently; 4.67 ± 0.81% of their body was irradiated at an average dose of 4.64 ± 0.67 Gy. Logistic regression analysis revealed that the total duration of all interventional procedures per week was associated with partial-body exposure levels.

CONCLUSIONS

Our findings suggest that interventional radiologists had greater chromosomal damages than those in other occupational groups, and their partial-body exposure levels might be high enough to cause local damage. Use of special dosimeters to monitor partial-body exposure, as well as restricting the time and frequency of interventional procedures, could help reduce occupational radiation exposure.

KEY POINTS

• Interventional radiologists had a higher number of dicentrics than the normal population and industrial radiographers. • The level of partial-body exposure of interventional radiologists might be high enough to cause occupational local damage such as a skin cancer in fingers. • Restricting the duration and frequency of interventional procedures might be helpful in reducing occupational radiation exposure.

Estimating Compton scatter distributions with a regressional neural network for use in a real-time staff dose management system for fluoroscopic procedures

Staff-dose management in fluoroscopic procedures is a continuing concern due to insufficient awareness of radiation dose levels. To maintain dose as low as reasonably achievable (ALARA), we have developed a software system capable of monitoring the procedure room scattered radiation and the dose to staff members in real-time during fluoroscopic procedures. The scattered-radiation display system (SDS) acquires imaging-system signal inputs to update technique and geometric parameters used to provide a color-coded mapping of room scatter. We have calculated a discrete look-up-table (LUT) of scatter distributions using Monte-Carlo (MC) software and developed an interpolation technique for the multiple parameters known to alter the spatial shape of the distribution. However, the file size for the LUT's can be large (~2GB), leading to long SDS installation times in the clinic. Instead, this work investigated the speed and accuracy of a regressional neural network (RNN) that we developed for predicting the scatter distribution from imaging-system inputs without the need for the LUT and interpolation. This method greatly reduces installation time while maintaining real-time performance. Results using error maps derived from the structural similarity index indicate high visual accuracy of predicted matrices when compared to the MC-calculated distributions. Dose error is also acceptable with a matrix element-averaged percent error of 31%. This dose-monitoring system for staff members can lead to improved radiation safety due to immediate visual feedback of high-dose regions in the room during the procedure as well as enhanced reporting of individual doses post-procedure.

Using a convolutional neural network for human recognition in a staff dose management software for fluoroscopic interventional procedures

Staff dose management is a continuing concern in fluoroscopically-guided interventional (FGI) procedures. Being unaware of radiation scatter levels can lead to unnecessarily high stochastic and deterministic risks due to the effects of absorbed dose by staff members. Our group has developed a scattered-radiation display system (SDS) capable of monitoring system parameters in real-time using a controller-area network (CAN) bus interface and displaying a color-coded mapping of the Compton-scatter distribution. This system additionally uses a time-of-flight depth sensing camera to track staff member positional information for dose rate updates. The current work capitalizes on our body tracking methodology to facilitate individualized dose recording via human recognition using 16-bit grayscale depth maps acquired using a Microsoft Kinect V2. Background features are removed from the images using a depth threshold technique and connected component analysis, which results in a body silhouette binary mask. The masks are then fed into a convolutional neural network (CNN) for identification of unique body shape features. The CNN was trained using 144 binary masks for each of four individuals (total of 576 images). Initial results indicate high-fidelity prediction (97.3% testing accuracy) from the CNN irrespective of obstructing objects (face masks and lead aprons). Body tracking is still maintained when protective attire is introduced, albeit with a slight increase in positional data error. Dose reports are then able to be produced which contain cumulative dose to each staff member at the eye lens level, waist level, and collar level. Individualized cumulative dose reporting through the use of a CNN in addition to real-time feedback in the clinic will lead to improved radiation dose management.

Characterisation and mapping of scattered radiation fields in interventional radiology theatres

We used the Timepix3 hybrid pixel detector technology in order to determine the exposure of medical personnel to ionizing radiation in an interventional radiology room. We measured the energy spectra of the scattered radiation generated by the patient during X-ray image-guided interventional procedures. We performed measurements at different positions and heights within the theatre. We first observed a difference in fluence for each staff member. As expected, we found that the person closest to the X-ray tube is the most exposed while the least exposed staff member is positioned at the patient’s feet. Additionally, we observed a shift in energy from head to toe for practitioners, clearly indicating a non-homogenous energy exposure. The photon counting Timepix3 detector provides a new tool for radiation field characterisation that is easier-to-use and more compact than conventional X-ray spectrometers. The spectral information is particularly valuable for optimising the use of radiation protection gear and improving dosimetry surveillance programs. We also found the device very useful for training purposes to provide awareness and understanding about radiation protection principles among interventional radiology staff.

Radiation protection knowledge and practices in interventional cardiologists practicing in Africa: a cross sectional survey

We conducted a survey of doctors working in the cardiac catheterisation laboratories in Africa on their knowledge, attitude and practice with respect to radiation protection. Of seventy-two respondents contacted, 61 (84.7%) completed the questionnaire. Twenty-eight, (45.9%) were younger than 45 years. Thirty-seven, (60.6%) had less than 10 years of experience in the laboratory. Only 28 (45.9%) had undertaken radiation protection training. Fifty-eight, (95.1%) consistently used lead aprons. Forty-seven, (77%) reported consistently using thyroid shields. Ten (16.4%) consistently used radiation protection eyeglasses, whilst 36 (59%) never used them. Thermoluminescent Dosimeter badges were consistently used in 23 (37.7%). Forty-two, (68.9%) reported having ceiling mounted lead/acrylic shields. Level of radiation exposure in the most recent one year was ≤2 mSv in 14, between 2 and 20 mSv in 8 and between 20 and 30 mSv in 2, whilst 33 did not know their dose readings. The use of basic radiation protection tools as well as the knowledge and measurement of radiation exposure among interventional cardiologists working in Africa is low. The unavailability of some of the protective tools and a knowledge gap in terms of radiation protection and monitoring of self-exposure were some of the reasons for suboptimal self-protection against ionising radiation among our respondents. We suggest that initiatives be taken by all stakeholders to train this group of medical professionals in basic radiation protection to avoid unnecessary exposure to themselves, co-workers and patients.

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 49 991, 81 561, 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% (450 173 of 1 366 736) of the one-badge entries were judged to be informative. There were 335 225 and 916 563 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 76 059 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, 4.6-11.2 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. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Karellas in this issue.

Immersive Radiation Experience for Interventional Radiology with Virtual Reality Radiation Dose Visualization Using Fast Monte Carlo Dose Estimation

For interventional radiology (IR), understanding the precise dose distribution is crucial to reduce the risks of radiation dermatitis to patients and staff. Visualization of dose distribution is expected to support radiation safety efforts immensely. This report presents techniques for perceiving the dose distribution using virtual reality (VR) technology and for estimating the air dose distribution accurately using Monte Carlo simulation for VR dose visualization. We adopted an earlier reported Monte-Carlo-based estimation system for IR and simulated the dose in a geometrical area resembling an IR room with fluoroscopic conditions. Users of our VR system experienced a simulated air dose distribution in the IR room while the irradiation angle, irradiation timing, and lead shielding were controlled. The estimated air dose was evaluated through comparison with measurements taken using a radiophotoluminescence glass dosimeter. Our dose estimation results were consistent with dosimeter readings, showing a 13.5% average mutual difference. The estimated air dose was visualized in VR: users could view a virtual IR room and walk around in it. Using our VR system, users experienced dose distribution changes dynamically with C-arm rotation. Qualitative tests were conducted to evaluate the workload and usability of our VR system. The perceived overall workload score (18.00) was lower than the scores reported in the literature for medical tasks (50.60) and computer activities (54.00). This VR visualization is expected to open new horizons for understanding dose distributions intuitively, thereby aiding the avoidance of radiation injury.

Personal Protective Equipment Availability and Utilization Among Interventionalists

OBJECTIVE

This study explored personal protective equipment (PPE) availability and PPE utilization among interventionalists in the catheterization laboratory, which is a highly contextualized workplace.

METHODS

This is a cross-sectional study using mixed methods. Participants (108) completed a survey. A hyperlink was sent to the participants, or they were asked to complete a paper-based survey. Purposively selected participants (54) were selected for individual (30) or group (six) interviews. The interviews were conducted at conferences, or appointments were made to see the participants. Logistic regression analysis was performed. The qualitative data were analyzed thematically.

RESULTS

Lead glasses were consistently used 10.2% and never used 61.1% of the time. All forms of PPE were inconsistently used by 92.6% of participants. Women were 4.3 times more likely to report that PPE was not available. PPE compliance was related to fit and availability.

CONCLUSIONS

PPE use was inconsistent and not always available. Improving the culture of radiation protection in catheterization laboratories is essential to improve PPE compliance with the aim of protecting patients and operators. This culture of radiation protection must include all those involved including the users of PPE and the administrators and managers who are responsible for supplying sufficient, appropriate, fitting PPE for all workers requiring such protection.

Cytogenetic status of interventional radiology unit workers occupationally exposed to low-dose ionising radiation: A pilot study

Interventional radiology unit workers represent one of the occupationally most exposed populations to low-dose ionizing radiation. Since there are many uncertainties in research of doses below 100 mSv, this study attempted to evaluate DNA damage levels in chronically exposed personnel. The study group consisted of 24 subjects matched with a control population by the number of participants, age, gender ratio, active smoking status, the period of blood sampling, and residence. Based on regular dosimetry using thermoluminiscent dosimeters, our study group occupationally received a dose of 1.82 ± 3.60 mSv over the last year. The results of the cytokinesis-block micronucleus assay and the comet assay showed a higher nuclear buds frequency (4.09 ± 1.88) and tail length (15.46 ± 1.47 μm) than in the control group (2.96 ± 1.67, 14.05 ± 1.36 μm, respectively). Differences in other descriptors from both tests did not reach statistical significance. Further investigations are needed to develop algorithms for improving personal dosimetry and those that would engage larger biomonitoring study groups.

Interventionalists' perceptions on a culture of radiation protection

BACKGROUND

Occupational exposure to ionising radiation poses potential health risks to radiation workers unless adequate protection is in place. The catheterisation laboratory is a highly contextualised workplace with a distinctive organisational and workplace culture.

OBJECTIVE

This study was conducted to understand the culture of radiation protection (CRP).

METHODS

This study was a qualitative study and data were collected through 30 in-depth and 6 group interviews with 54 purposively selected South African interventionalists (interventional radiologists and cardiologists). The participants included a diversity of interventionalists who varied in sex, geographic location and years of experience with fluoroscopy. The transcribed data were analysed thematically using a deductive and inductive approach.

RESULTS

'Culture of radiation protection' emerged as a complex theme that intersected with other themes: 'knowledge and awareness of radiation', 'radiation safety practice', 'personal protective equipment (PPE) utilisation' and 'education and training'.

CONCLUSION

Establishing and sustaining a CRP provides an opportunity to mitigate the potentially detrimental health effects of occupational radiation exposure. Education and training are pivotal to establishing a CRP. The time to establish a culture of radiation in the catheterisation laboratory is now.

Fast skin dose estimation system for interventional radiology

To minimise the radiation dermatitis related to interventional radiology (IR), rapid and accurate dose estimation has been sought for all procedures. We propose a technique for estimating the patient skin dose rapidly and accurately using Monte Carlo (MC) simulation with a graphical processing unit (GPU, GTX 1080; Nvidia Corp.). The skin dose distribution is simulated based on an individual patient's computed tomography (CT) dataset for fluoroscopic conditions after the CT dataset has been segmented into air, water and bone based on pixel values. The skin is assumed to be one layer at the outer surface of the body. Fluoroscopic conditions are obtained from a log file of a fluoroscopic examination. Estimating the absorbed skin dose distribution requires calibration of the dose simulated by our system. For this purpose, a linear function was used to approximate the relation between the simulated dose and the measured dose using radiophotoluminescence (RPL) glass dosimeters in a water-equivalent phantom. Differences of maximum skin dose between our system and the Particle and Heavy Ion Transport code System (PHITS) were as high as 6.1%. The relative statistical error (2 σ) for the simulated dose obtained using our system was ≤3.5%. Using a GPU, the simulation on the chest CT dataset aiming at the heart was within 3.49 s on average: the GPU is 122 times faster than a CPU (Core i7-7700K; Intel Corp.). Our system (using the GPU, the log file, and the CT dataset) estimated the skin dose more rapidly and more accurately than conventional methods.

WORK PRACTICES AND RADIATION EXPOSURE AMONG MALE RADIOLOGIC TECHNOLOGISTS ASSISTING FLUOROSCOPICALLY GUIDED INTERVENTIONAL PROCEDURES

This study investigated occupational characteristics and radiation exposure among radiologic technologists assisting fluoroscopically guided interventional (FGI) procedures. A nationwide survey of radiologic technologists in South Korea was conducted. Among 8058 male respondents, 664 (8.2%) assisted FGI procedures. The survey data were linked with dosimetry data from the National Dose Registry. Most radiologic technologists assisting FGI procedures were 30-40 years old and employed by general hospitals. These technologists worked in closer proximity to patients during procedures, less frequently used shield screens, more commonly utilized protective devices, and less commonly wore badge dosemeters than the ones not assisting FGI procedures. The average annual effective dose did not differ according to the performance of FGI procedures. The average cumulative effective dose among radiologic technologists assisting FGI procedures was significantly greater for those who had recently entered the field and personnel in rural areas than for those who did not assist these procedures.

Reduced Patient Radiation Exposure during Neurodiagnostic and Interventional X-Ray Angiography with a New Imaging Platform

BACKGROUND AND PURPOSE

Advancements in medical device and imaging technology as well as accruing clinical evidence have accelerated the growth of the endovascular treatment of cerebrovascular diseases. However, the augmented role of these procedures raises concerns about the radiation dose to patients and operators. We evaluated patient doses from an x-ray imaging platform with radiation dose-reduction technology, which combined image noise reduction, motion correction, and contrast-dependent temporal averaging with optimized x-ray exposure settings.

MATERIALS AND METHODS

In this single-center, retrospective study, cumulative dose-area product inclusive of fluoroscopy, angiography, and 3D acquisitions for all neurovascular procedures performed during a 2-year period on the dose-reduction platform were compared with a reference platform. Key study features were the following: The neurointerventional radiologist could select the targeted dose reduction for each patient with the dose-reduction platform, and the statistical analyses included patient characteristics and the neurointerventional radiologist as covariates. The analyzed outcome measures were cumulative dose (kerma)-area product, fluoroscopy duration, and administered contrast volume.

RESULTS

A total of 1238 neurointerventional cases were included, of which 914 and 324 were performed on the reference and dose-reduction platforms, respectively. Over all diagnostic and neurointerventional procedures, the cumulative dose-area product was significantly reduced by 53.2% (mean reduction, 160.3 Gy × cm²; P < .0001), fluoroscopy duration was marginally significantly increased (mean increase, 5.2 minutes; P = .0491), and contrast volume was nonsignificantly increased (mean increase, 15.3 mL; P = .1616) with the dose-reduction platform.

CONCLUSIONS

A significant reduction in patient radiation dose is achievable during neurovascular procedures by using dose-reduction technology with a minimal impact on workflow.

RADIATION PROTECTION IN AN INTERVENTIONAL LABORATORY: A COMPARATIVE STUDY OF AUSTRALIAN AND SAUDI ARABIAN HOSPITALS

This study aimed to investigate whether the use of protection devices and attitudes of interventional professionals (including radiologists, cardiologists, vascular surgeons, medical imaging technicians and nurses) towards radiation protection will differ between Saudi Arabian and Australian hospitals. Hard copies of an anonymous survey were distributed to 10 and 6 clinical departments in the Eastern province of Saudi Arabia and metropolitan hospitals in Western Australia, respectively. The overall response rate was 43 % comprising 110 Australian participants and 63 % comprising 147 Saudi participants. Analysis showed that Australian respondents differed significantly from Saudi respondents with respect to their usages of leaded glasses (p < 0.001), ceiling-suspended lead screen (p < 0.001) and lead drape suspended from the table (p < 0.001). This study indicates that the trained interventional professionals in Australia tend to adhere to benefit from having an array of tools for personal radiation protection than the corresponding group in Saudi Arabia.

THE EFFECT OF RADIATION SHIELDS ON OPERATOR EXPOSURE DURING CONGENITAL CARDIAC CATHETERISATION

Cardiac catheterisation personnel are exposed to occupational radiation and its health risks. Little data exist regarding the efficacy of radiation-protective equipment from congenital catheterisation laboratories (CLs). The authors retrospectively reviewed data in which CL operators wore a radiation dosemeter during catheterizations on patients of >20 kg. A leaded under-table skirt was present in all cases. Three additional radiation-protective devices were utilised at operator discretion: a top extension to the under-table skirt, a ceiling-mounted shield and a disposable patient drape. Case details, operator position, fluoroscopy time, incident air KERMA in the patient plane (K, mGy) and dose-area product (DAP, µGy·m²) were recorded. A total of 136 catheterizations over 8 months were included. Median operator dose (OpD) was 12 µSv (range 0-930) and indexed to K and DAP to correct for patient factors and case times. Indexed OpD decreased significantly with each additional shield used (14.8 vs. 1.3 nSv µGy^-1 m^-2 and 124 vs. 14 nSv mGy^-1 with one and four shields, respectively, p < 0.001). This trend was not significant with operator at head-of-bed. Combinations that included the ceiling shield had the lowest indexed OpD. The patient drape did not further reduce OpD when all other shields were used (1.3 vs. 2.2 nSv µGy^-1 m^-2, p = 0.5; 14 vs. 17 nSv mGy^-1, p = 0.4) and was associated with higher patient exposure indexed to weight and fluoroscopy time (4.5 vs. 3.1 µGy m² kg-min^-1, p = 0.009; and 0.51 vs. 0.38 mGy kg-min^-1, p = 0.01). Supplemental radiation barriers can decrease operator-absorbed radiation. A ceiling-mounted shield may provide greatest benefit. The authors do not recommend routine use of disposable patient drapes.

OPTIMISATION OF OCCUPATIONAL RADIATION PROTECTION IN IMAGE-GUIDED INTERVENTIONS: EXPLORING VIDEO RECORDINGS AS A TOOL IN THE PROCESS

The overall purpose of this work was to explore how video recordings can contribute to the process of optimising occupational radiation protection in image-guided interventions. Video-recorded material from two image-guided interventions was produced and used to investigate to what extent it is conceivable to observe and assess dose-affecting actions in video recordings. Using the recorded material, it was to some extent possible to connect the choice of imaging techniques to the medical events during the procedure and, to a less extent, to connect these technical and medical issues to the occupational exposure. It was possible to identify a relationship between occupational exposure level to staff and positioning and use of shielding. However, detailed values of the dose rates were not possible to observe on the recordings, and the change in occupational exposure level from adjustments of exposure settings was not possible to identify. In conclusion, the use of video recordings is a promising tool to identify dose-affecting instances, allowing for a deeper knowledge of the interdependency between the management of the medical procedure, the applied imaging technology and the occupational exposure level. However, for a full information about the dose-affecting actions, the equipment used and the recording settings have to be thoroughly planned.

The Use of Laser Guidance Reduces Fluoroscopy Time for C-Arm Cone-Beam Computed Tomography-Guided Biopsies

PURPOSE

When using laser guidance for cone-beam computed tomography (CBCT)-guided needle interventions, planned needle paths are visualized to the operator without the need to switch between entry- and progress-view during needle placement. The current study assesses the effect of laser guidance during CBCT-guided biopsies on fluoroscopy and procedure times.

MATERIALS AND METHODS

Prospective data from 15 CBCT-guided biopsies of 8-65 mm thoracic and abdominal lesions assisted by a ceiling-mounted laser guidance technique were compared to retrospective data of 36 performed CBCT-guided biopsies of lesions >20 mm using the freehand technique. Fluoroscopy time, procedure time, and number of CBCT-scans were recorded. All data are presented as median (ranges).

RESULTS

For biopsies using the freehand technique, more fluoroscopy time was necessary to guide the needle onto the target, 165 s (83-333 s) compared to 87 s (44-190 s) for laser guidance (p < 0.001). Procedure times were shorter for freehand-guided biopsies, 24 min versus 30 min for laser guidance (p < 0.001).

CONCLUSION

The use of laser guidance during CBCT-guided biopsies significantly reduces fluoroscopy time.

Interventional Radiologists: a Necessary Evaluation of Technical, Protective and Technological Operation

BACKGROUND AND PURPOSE

To present the results of occupational radiation doses investigated through a Hospitals of Mazandaran Medical Science Universities in north of Iran. Radiology unit has an important role in diagnosis of many disorders with providing suitable and high quality pictures. A good picture was provided using correct technical criteria and suitable circumstance of patient. Finally, operation and knowledge of radiology personnel directly has a primary role in determining quality of radiography.

MATERIALS AND METHODS

This study was done in order to determine personnel operation in the units of hospitals radiologist related to University of Mazandaran Medical Science. Data collection tools are made of a researcher check list that was used after obtaining suitable letter and validity indexes. All of the 73 personnel of radiology unit related to Mazandaran Medical Science were studied. 35 operations (in technical, protective and technological fields) of any personnel, in three distinct shifts were observed and recorded. All of them were tested regarding these three fields with a total of 40 questions.

RESULTS

The total scores received from personnel in technical part in the morning, evening and night shift were 66.4, 53.9 and 60.2 percent respectively. Received scores from personnel in the protective fields were 68.1, 59.5 and 60.2 percent. Moreover, received scores from personnel in the technological operation fields were 47.8, 39.95 and 43.65 percent respectively. Comparison of these three scores in technical, protective and technological operation fields showed a meaningful difference (p<0.05).

CONCLUSION

The overall quality of personnel operations were nearly desirable and in need of continuous education, supervision and evaluation. Emphasizing protection to beams, accessibility of necessary tools, continuous supervision regarding the usage of these equipments and respecting the other security points have an important role in decreasing patients absorbed doses.

Radiation exposure among medical professionals working in the Intensive Care Unit

Background and Aims:

With the expanding use of diagnostic and therapeutic radiological modalities in critically ill patients, doctors working in Intensive Care Units (ICUs) are increasingly exposed to ionizing radiation. This risk of radiation exposure occurs not only during bedside radiologic procedures, but also when ICU physicians accompany patients to radiology suites. The aim of this study was to quantify levels of radiation exposure among medical professionals working in the ICU.

Materials and Methods:

The study was carried out prospectively over 6 months in the ICU of a tertiary-referral cancer hospital. Two teams consisting of 4 ICU resident doctors each were instructed to wear thermoluminescent dosimeters (TLDs) during their duty shifts. Standard radiation protection precautions were used throughout the study period. TLDs were also placed in selected areas of the ICU to measure the amount of scattered radiation. TLDs were analyzed at the end of every 3 months.

Results:

The readings recorded on TLDs placed in the ICU were almost immeasurable. The mean value of residents' radiation exposure was 0.059 mSv, though the highest individual reading approached 0.1 mSv. The projected maximum yearly radiation exposure was 0.4 mSv.

Conclusions:

If standard radiation safety precautions are followed, the cumulative radiation exposure to ICU resident doctors is well within permissible limits and is not a cause of concern. However, with the increasing use of radiological procedures in the management of critically ill patients, there is a need to repeat such audits periodically to monitor radiation exposure.