Occupational radiation doses to operators performing fluoroscopically-guided procedures

Occupational Radiation Dose Trends in U.S. Radiologic Technologists Assisting with Fluoroscopically Guided Interventional Procedures, 1980-2020

PURPOSE

To summarize dose trends from 1980 to 2020 for 19,651 U.S. Radiologic Technologists who reported assisting with fluoroscopically guided interventional procedures (FGIPs), overall and by work history characteristics.

MATERIALS AND METHODS

A total of 762,310 annual personal dose equivalents at a 10-mm reference depth (doses) during 1980-2020 for 43,823 participants of the U.S. Radiologic Technologists (USRT) cohort who responded to work history questionnaires administered during 2012-2014 were summarized. This population included 19,651 technologists who reported assisting with FGIP (≥1 time per month for ≥12 consecutive months) at any time during the study period. Doses corresponding to assistance with FGIP were estimated in terms of proximity to patients, monthly procedure frequency, and procedure type. Box plots and summary statistics (eg, medians and percentiles) were used to describe annual doses and dose trends.

RESULTS

Median annual dose corresponding to assistance with FGIP was 0.65 mSv (interquartile range [IQR], 0.60-1.40 mSv; 95th percentile, 6.80). Higher occupational doses with wider variability were associated with close proximity to patients during assistance with FGIP (median, 1.20 mSv [IQR, 0.60-4.18 mSv]; 95th percentile, 12.66), performing ≥20 FGIPs per month (median, 0.75 mSv [IQR, 0.60-2.40 mSv]; 95th percentile, 9.44), and assisting with high-dose FGIP (median, 0.70 mSv [IQR, 0.60-1.90 mSv]; 95th percentile, 8.30).

CONCLUSIONS

Occupational doses corresponding to assistance with FGIP were generally low but varied with exposure frequency, procedure type, and proximity to patients. These results highlight the need for vigilant dose monitoring, radiation safety training, and proper protective equipment.

Occupational dose measurement in interventional cardiology practice

Ensuring the safety of healthcare workers in interventional cardiology necessitates effective monitoring of occupational radiation exposure. This study aims to assess the accuracy of the over-apron single dosimetric approach compared with double dosimetric methods and explore the relationship between under-apron and over-apron doses. This investigation showed that the prescribed annual dose constraint of 20 mSv year-1 was not exceeded by the maximum annual occupational doses determined by dosimetric algorithms, which were 0.13 ± 0.02, 0.15 ± 0.02 and 0.27 ± 0.04 mSv, respectively. The study demonstrated excellent statistically significant correlations among single and double dosimetric algorithms and between direct under-apron and over-apron doses. Consequently, single dosimetric algorithms could effectively estimate doses for double dosimetric algorithms, highlighting the limited added value of under-apron measurements. These findings significantly impact the practice of interventional cardiology in Sri Lanka, playing a crucial role in enhancing radiation protection measures.

Radiation dose to multidisciplinary staff members during complex interventional procedures

INTRODUCTION

Complex interventional radiology procedures involve extensive fluoroscopy and image acquisition while staff are in-room. Monitoring occupational radiation dose is crucial in optimization. The purpose was to determine radiation doses received by staff involved in complex interventional procedures performed in a dedicated vascular or neuro intervention room.

METHODS

Individual real-time radiation dose for all staff involved in vascular and neuro-interventional procedures in adult patients was recorded over a one-year period using wireless electronic dosimeters attached to the apron thyroid shield. A reference dosimeter was attached to the C-arm near the tube housing to measure scattered, unshielded radiation. Radiology staff carried shoulder thermo-luminescent dosimeters with monthly read-out to monitor dose over time.

RESULTS

Occupational radiation dose was measured in 99 interventional procedures. In many cases prostate artery embolization procedures exposed radiologists to high radiation doses with a median of 15.0 μSv and a very large spread, i.e. 0.2-152.5 μSv. In all procedures except uterine fibroid embolization radiographers were exposed to lower doses than those of radiologists, with endovascular aortic repair being the procedure with highest median exposure to assisting radiographers, i.e. 2.2 μSv ranging from 0.1 to 36.1 μSv. Median radiation dose for the reference dosimeter was 670 μGy while median staff dose for all procedures combined was 3.2 μGy.

CONCLUSION

Radiation doses for multiple staff were determined and the ratio between staff dose and reference dosimeter indicated proper use of shielding in general. Some high-dose procedures may need further optimization for certain staff members, especially those not primarily employed in radiology.

IMPLICATIONS FOR PRACTICE

The study provides benchmark doses that may be used widely in audits and in the ongoing effort to optimize radiation protection for staff in interventional radiology.

Influence of resident involvement on fluoroscopy time and ionizing radiation exposure in fluoroscopy-guided spinal procedures

BACKGROUND

Fluoroscopic guidance has become the standard for a variety of medical procedures. Mastering these techniques requires practice, which may entail additional radiation for patients and providers. Despite their widespread use, the literature examining factors influencing radiation exposure in fluoroscopically guided pain procedures is scarce.

OBJECTIVE

To evaluate the influence of resident involvement on radiation exposure during fluoroscopy-guided spinal interventions.

DESIGN

Single-center, observational study.

SETTING

Outpatient physiatry clinic in a teaching hospital.

PATIENTS

All patients who received cervical or lumbar facet block(s) (FBs), transforaminal epidural steroid injection(s) (TFESIs) without digital subtraction, or a caudal epidural (CE) during the study period were included.

INTERVENTIONS

Resident involvement in the procedures: absent, observing, or participating.

MAIN OUTCOME MEASURES

Machine-indicated fluoroscopy time (seconds) and radiation dose (milligrays [mGy]).

RESULTS

Two hundred ninety six procedures were included: 188 FBs (58 cervical, 130 lumbar), 48 CEs, and 60 TFESIs. For lumbar FBs, fluoroscopy time and radiation dose increased significantly when residents performed them (meantime  = 24.5 s, confidence interval [CI] = 20.4-28.7; meandose  = 3.53 mGy, CI = 2.57-4.49) compared to when they observed (meantime  = 9.9 s, CI = 8.1-11.7; meandose  = 1.28 mGy, CI = 0.98-1.59) (mean difference: time = 14.63 s, CI = 9.31-19.94; dose = 2.25 mGy, CI = 1.17-3.33) and were absent during the procedure (meantime  = 12.9 s, CI = 11.1-14.6; meandose  = 1.65 mGy, CI = 1.40-1.89) (mean difference: time = 11.67 s, CI = 7.35-15.98; dose = 1.88 mGy, CI = 1.01-2.76). In the case of TFESIs, time, but not dose, increased significantly when residents observed (meantime  = 39.1 s, CI = 30.7-47.6; meandose  = 6.73 mGy, CI = 3.39-10.07) compared to when they were absent (meantime  = 27.1 s, CI = 22.4-31.8; meandose  = 4.41 mGy, CI = 3.06-5.76 (mean difference: time = 11.99 s, CI = 1.37-22.61; dose = 2.32 mGy, CI = -1.20-5.84). Finally, resident involvement did not significantly affect the outcomes for CEs (ptime  = .032, pdose  = .74) and cervical FBs (ptime  = .64, pdose  = .68).

CONCLUSION

Resident participation affected lumbar FBs the most, with an increase in both fluoroscopy time and radiation dose.

Assessment of dosimetric approaches in evaluating radiation exposure for interventional cardiologists in Sri Lanka

Interventional cardiologists face significant radiation exposure during interventional cardiology procedures. Therefore, this study focuses on assessing radiation exposure among interventional cardiologists during their procedures. Specifically, it aims to determine the effectiveness of both single and double dosimeter methods in estimating annual occupational radiation doses. This research holds pioneering significance as it represents the very first study undertaken in Sri Lanka. Thirteen interventional cardiologists performed 486 interventional cardiology procedures over three months in three different healthcare institutes. Active Hp(10) dosimeters were placed to measure radiation exposure. Effective doses were calculated using single and double dosimetric algorithms. Annual occupational doses were assessed on an operator basis. Statistical analyses were conducted to assess algorithmic differences and dose variations using the Kruskal-Wallis test and linear regression. The highest annual occupational dose for each dosimetric algorithm received as 2.00 ± 0.24 mSv, 2.29 ± 0.48 mSv, 3.35 ± 0.71 mSv, and 2.64 ± 0.42 mSv, respectively, and remained below the recommended safety limit of 20 mSv/year. The Kruskal-Wallis test revealed no significant differences in the effective doses among double dosimetric algorithms, as well as between single and double dosimetric algorithms (p > 0.05). Linear regression showed strong correlations among various algorithms, demonstrating consistency. The findings of this study hold significant effects on interventional cardiology practice in Sri Lanka, enhancing radiation safety and monitoring.

Pelphix: Surgical Phase Recognition from X-ray Images in Percutaneous Pelvic Fixation

Surgical phase recognition (SPR) is a crucial element in the digital transformation of the modern operating theater. While SPR based on video sources is well-established, incorporation of interventional X-ray sequences has not yet been explored. This paper presents Pelphix, a first approach to SPR for X-ray-guided percutaneous pelvic fracture fixation, which models the procedure at four levels of granularity - corridor, activity, view, and frame value - simulating the pelvic fracture fixation workflow as a Markov process to provide fully annotated training data. Using added supervision from detection of bony corridors, tools, and anatomy, we learn image representations that are fed into a transformer model to regress surgical phases at the four granularity levels. Our approach demonstrates the feasibility of X-ray-based SPR, achieving an average accuracy of 99.2% on simulated sequences and 71.7% in cadaver across all granularity levels, with up to 84% accuracy for the target corridor in real data. This work constitutes the first step toward SPR for the X-ray domain, establishing an approach to categorizing phases in X-ray-guided surgery, simulating realistic image sequences to enable machine learning model development, and demonstrating that this approach is feasible for the analysis of real procedures. As X-ray-based SPR continues to mature, it will benefit procedures in orthopedic surgery, angiography, and interventional radiology by equipping intelligent surgical systems with situational awareness in the operating room.

Editor's Choice - Estimated Radiation Dose to the Operator During Endovascular Aneurysm Repair

OBJECTIVE

To estimate operator organ doses from fluoroscopically guided infrarenal endovascular aneurysm repair (EVAR) procedures, using the detailed exposure information contained in radiation dose structured reports.

METHODS

Conversion factors relating kerma area product (PKA) to primary operator organ doses were calculated using Monte Carlo methods for 91 beam angles and seven x-ray spectra typical of clinical practice. A computer program was written, which selects the appropriate conversion factor for each exposure listed in a structured report and multiplies it by the respective PKA. This system was used to estimate operator doses for 81 EVAR procedures for which structured reports were available. The impact of different shielding scenarios and variations in operator position was also investigated.

RESULTS

Without any shielding, the median estimated effective dose was 113 μSv (interquartile range [IQR] 71, 252 μSv). The highest median organ doses were for the colon (154 μSv, IQR 81, 343) and stomach (133 μSv, IQR 76, 307). These dose estimates represent all exposures, including fluoroscopy and non-fluoroscopic digital acquisitions. With minimal shielding provided by 0.25 mm of Pb covering the torso and upper legs, the effective dose was reduced by a factor of around 6. With additional shielding from ceiling and table shields, a 25 to 50 fold reduction in dose is achievable. Estimated doses were highest where the primary beam was pointed directly away from the operator.

CONCLUSION

The models suggest that with optimal use of shielding, operator doses can be reduced to levels equivalent to one to two days of natural background exposure and well below statutory dose limits.

Radiation dose during interventional cardiology procedures: portable C-arm vs. a new generation fluoroscopy system

INTRODUCTION

Occupational exposure to ionizing radiation poses health risks for veterinary interventionalists. There are limited veterinary studies evaluating radiation dose in the cardiac catheterization laboratory. The purpose of this study was to report direct radiation dose exposure to patients during common interventional cardiology procedures and compare these doses between two fluoroscopy units.

ANIMALS

One hundred and fifty-four client-owned dogs.

MATERIALS AND METHODS

Patient dose during procedures using a portable C-arm were retrospectively analyzed and compared to those performed in a contemporary interventional suite. Fluoroscopy equipment, procedure type, operator, patient weight, fluoroscopy time, dose area product, and air kerma were recorded and statistically modeled using univariable and multivariable linear regression to evaluate the effect of each factor.

RESULTS

Patient dose population (154 dogs), comprised 61 patent ductus arteriosus occlusions, 60 balloon pulmonary valvuloplasties, and 33 pacemaker implantations. Patient dose was significantly lower in the group utilizing a newer generation fluoroscopy unit vs. the group utilizing an older portable C-arm, positively correlated with patient weight, and highest during balloon pulmonary valvuloplasties compared to patent ductus arteriosus occlusions or pacemaker implantations (all p<0.010).

DISCUSSION

Newer fluoroscopy systems can be equipped with technologies that improve image quality while reducing patient dose and radiation exposure to interventional personnel.

CONCLUSIONS

We documented a significant reduction in patient radiation dose using a newer fluoroscopy system as compared to an older portable C-arm for interventional cardiology procedures in animals. Improved knowledge of patient radiation dose factors may promote better radiation safety protocols in veterinary interventional cardiology.

Radiation exposure to staff during fluoroscopic endoscopic procedures

Objectives

Fluoroscopically guided procedures utilize ionizing radiation to assist in the diagnosis and treatment of the patient. The use of ionizing radiation is not without risk to the operator and other staff members present during endoscopic procedures. This study simulates radiation exposure during endoscopic retrograde cholangiopancreatography procedures under different shielded conditions and provides practical radiation safety recommendations, through easy‐to‐use visual guides.

Methods

We obtained radiation exposure measurements at varying locations with different shielding setups surrounding a mobile C‐arm fluoroscopic unit while imaging a patient equivalent phantom at different heights. Heat maps were generated for the various conditions to provide visual guides for radiation protection.

Results

Different heat maps detailing various shielding methods have been generated to assist in determining the dose rate at varying locations surrounding the patient. The use of appropriate radiation protection could decrease the staff dose by up to 98%.

Conclusion

Although minor per procedure, the magnitude of radiation exposure will accumulate over the staff's working life. As such, it is recommended that precautions be taken during fluoroscopically guided endoscopy procedures to ensure radiation is kept as low as reasonably achievable.

Occupational and patient doses for interventional radiology integrated into a dose management system

OBJECTIVES

The International Commission on Radiological Protection recommends managing patient and occupational doses as an integrated approach, for the optimisation of interventional procedures. The conventional passive personal dosimeters only allow one to know the accumulated occupational doses during a certain period of time. This information is not enough to identify if there is a lack of occupational radiation protection during some procedures. This paper describes the use of a dose management system (DMS) allowing patient and occupational doses for individual procedures to be audited.

METHODS

The DMS manages patient and occupational doses measured by electronic personal dosimeters. One dosemeter located at the C-arm is used as a reference for scatter radiation. Data have been collected from five interventional rooms. Dosimetry data can be managed for the whole procedure and the different radiation events. Optimisation is done through auditing different sets of parameters for individual procedures: patient dose indicators, occupational dose values, the ratio between occupational doses, and the doses measured by the reference dosemeter at the C-arm, and the ratio between occupational and patient dose values.

RESULTS

The managed data correspond to the year 2021, with around 4500 procedures, and 8000 records on occupational exposures. Patient and staff dose data (for 11 cardiologists, 7 radiologists and 8 nurses) were available for 3043 procedures. The DMS allows alerts for patient dose indicators and occupational exposures to be set.

CONCLUSIONS

The main advantage of this integrated approach is the capacity to improve radiation safety for patients and workers together, auditing alerts for individual procedures.

ADVANCES IN KNOWLEDGE

The management of patient and occupational doses together (measured with electronic personal dosimeters) for individual interventional procedures, using dose management systems, allows alerting optimisation on high-dose values for patients and staff.

Modified design of x-ray protective clothing to enhance radiation protection for interventional radiologists

BACKGROUND

In interventional radiology procedures, the operator typically stands on the right side of the patient's right thigh to manipulate devices through the femoral sheath. Because the standard x-ray protective clothing is designed as sleeveless and scatter radiations from the patient are mainly incident from the left-anterior direction to the operator, the arm hole of the clothing may be a significant unprotected area, contributing to an increase in the operator's organ doses and effective dose.

PURPOSE

This study aimed to compare the organ doses and effective dose received by the interventional radiologist when wearing the standard x-ray protective clothing and when wearing the modified clothing with an additional shoulder guard.

METHODS

The experimental setup aimed to simulate actual clinical practice in interventional radiology. The patient phantom was located at the beam center to generate scatter radiation. An adult female anthropomorphic phantom loaded with 126 nanoDots (Landauer Inc., Glenwood, IL) was used to measure organ and effective doses to the operator. The standard wrap-around type x-ray protective clothing offered 0.25-mm lead-equivalent protection, and the frontal overlap area offered 0.50-mm lead-equivalent protection. The shoulder guard was custom-made with a material providing x-ray protection equivalent to lead of 0.50 mm thickness. The organ and effective doses were compared between the operator wearing the standard protective clothing and the one wearing the modified clothing with a shoulder guard.

RESULTS

After adding the shoulder guard, doses to the lungs, bone marrow, and esophagus decreased by 81.9%, 58.6%, and 58.7%, respectively, and the effective dose to the operator decreased by 47.7%.

CONCLUSIONS

Widespread use of modified x-ray protective clothing with shoulder guards can significantly decrease the overall occupational radiation risk in interventional radiology.

Next step trauma and orthopaedic surgery: integration of augmented reality for reduction and nail implantation of tibial fractures

INTRODUCTION

There is a tremendous scope of hardware and software development going on in augmented reality (AR), also in trauma and orthopaedic surgery. However, there are only a few systems available for intra-operative 3D imaging and guidance, most of them rely on peri- and intra-operative X-ray imaging. Especially in complex situations such as pelvic surgery or multifragmentary multilevel fractures, intra-operative 3D imaging and implant tracking systems have proven to be of great advantage for the outcome of the surgery and can help reduce X-ray exposure, at least for the surgical team (Ochs et al. in Injury 41:1297 1305, 2010). Yet, the current systems do not provide the ability to have a dynamic live view from the perspective of the surgeon. Our study describes a prototype AR-based system for live tracking which does not rely on X-rays.

MATERIALS AND METHODS

A protype live-view intra-operative guidance system using an AR head-mounted device (HMD) was developed and tested on the implantation of a medullary nail in a tibia fracture model. Software algorithms that allow live view and tracking of the implant, fracture fragments and soft tissue without the intra-operative use of X-rays were derived.

RESULTS

The implantation of a medullar tibia nail is possible while only relying on AR-guidance and live view without the intra-operative use of X-rays.

CONCLUSIONS

The current paper describes a feasibility study with a prototype of an intra-operative dynamic live tracking and imaging system that does not require intra-operative use of X-rays and dynamically adjust to the perspective of the surgeons due to an AR HMD. To our knowledge, the current literature does not describe any similar systems. This could be the next step in surgical imaging and education and a promising way to improve patient care.

Radiation reduction in a modern catheterization laboratory: A single-center experience

BACKGROUND

Measures were undertaken at the Cleveland Clinic to reduce radiation exposure to patients and personnel working in the catheterization laboratories. We report our experience with these improved systems over a 7-year period in patients undergoing diagnostic catheterization (DC) and percutaneous coronary interventions (PCIs).

METHODS

Patients were categorized into preinitiative (2009-2012) and postinitiative (2013-2019) groups in the DC and PCI cohorts. Propensity score matching was done between the pre- and postinitiative groups for both cohorts based on age, sex, body surface area, total fluoroscopy time, and total acquisition time. The effectiveness of radiation reduction measures was assessed by comparing the total air kerma (K_a,r ), and fluoroscopy- and acquisition-mode air kerma in patients in the two groups.

RESULTS

In the DC cohort, there was a significant reduction in K_a,r in the postinitiative group in comparison to the preinitiative group (median, 396 vs. 857 mGy; p < 0.001). In the PCI cohort, K_a,r in the postinitiative group was 1265 mGy, which was significantly lower than the corresponding values in the preinitiative group (1994 mGy; p < 0.001). We also observed a significant reduction in fluoroscopy- and acquisition-based air kerma rates, and air kerma area product in the postinitiative group in comparison to the preinitiative group in both matched and unmatched DC and PCI cohorts after the institution of radiation reduction measures.

CONCLUSION

There was a significant and sustained reduction in radiation exposure to patients in the catheterization laboratory with the implementation of advanced protocols. Similar algorithms can be applied in other laboratories to achieve a similar reduction in radiation exposure.

Ratios of Eye Lens and Hand Equivalent Doses with Whole-Body Effective Doses for Operators Performing Interventional Radiological Procedures

ABSTRACT

Estimating radiation doses for operators performing interventional radiological procedures is crucial in the occupational radiation protection of medical staff. In this study, Monte Carlo simulations coupled with an anthropomorphic phantom were used to model various exposure scenarios during the procedures. Conversion coefficients of the dose-area product of x rays for the eye lens equivalent dose, hand equivalent dose, and whole-body effective dose of the operator were calculated. Accordingly, the relationships between these dose quantities in typical interventional configurations were established, considering various source locations, tube voltages, and use of protective equipment or not. The results are presented in a systematic way for easy comparison and use. Tables and figures of the data can be helpful to provide estimates of eye lens and hand equivalent doses when records of specific dosimeters are absent, such as in the retrospective assessment of operators' eye lens and hand equivalent doses in past practices.

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.

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.

Evaluation of circulating cell-free nucleic acids in health workers occupationally exposed to ionizing radiation

Radiology workers might constantly be exposed to low-dose ionizing radiation due to their profession. Low doses of radiation in a short exposure time have the potential to alter the genome, which might potentially lead to diseases. The main objective of this study was to determine whether the amount of cell-free nucleic acids in plasma samples of radiation-exposed workers was different from the general public, in other words, non-exposed individuals. In this context, we investigated the association between radiation exposure and cell-free nucleic acids concentration by using radiation exposure parameters. The study consisted of 40 radiology workers and 40 individuals who were not exposed to ionizing radiation. The plasma concentrations of cell-free DNA, RNA, and miRNA were measured fluorometrically. We found that the ccfRNA concentration of the radiation-exposed group was significantly different from that of the non-exposed group (p = 0.0001). However, there are no differences between both groups in terms of ccfDNA and ccfmiRNA concentration. The concentration of ccfDNA is significantly correlated with working time in the fluoroscopy field (p < 0.05). We found that the concentration of ccfmiRNA was significantly correlated with working time in plain radiography (p < 0.01) and computed tomography (p < 0.05) and with total working time (p < 0.01). Similarly, the concentrations of ccfRNA were significantly correlated with working time in computed tomography (p < 0.01) and with the total working time (p < 0.05) of the workers. We found that imaging number in computed tomography significantly altered the level of ccfRNA (p = 0.006) and that working time in the computed tomography field significantly affected the ccfRNA concentration (p = 0.03, R² = 0.36 for model). Finally, we determined that total working time was significantly associated with total ccfRNA concentration (p < 0.05, R² = 0.25 for model). In conclusion, total RNA measured in radiation-exposed workers has the potential to predict the radiation exposure risk. Furthermore, total working time and working time in the tomography field significantly alter the level of free nucleic acids.

What Is Worth Knowing in Interventional Practices about Medical Staff Radiation Exposure Monitoring: A Review of Recent Outcomes of EURADOS Working Group 12

EURADOS (European Radiation Dosimetry Group) Working Group 12 (WG12) SG1 activities are aimed at occupational radiation protection and individual monitoring in X-ray and nuclear medicine practices. In recent years, many studies have been carried out in these fields, especially for interventional radiology and cardiology workplaces (IC/IR). The complexity of the exposure conditions of the medical staff during interventional practices makes the radiation protection and monitoring of the exposed workers a challenging task. The scope of the present work is to review some of the main results obtained within WG12 activities about scattered field characterization and personal dosimetry that could be very useful in increasing the quality of radiation protection of the personnel, safety, and awareness of radiation risk. Two papers on Monte Carlo modelling of interventional theater and three papers on active personal dosimeters (APDs) for personnel monitoring were considered in the review. More specifically, Monte Carlo simulation was used as the main tool to characterize the levels of exposure of the medical staff, allowing to determine how beam energy and direction can have an impact on the doses received by the operators. Indeed, the simulations provided information about the exposure of the operator’s head, and the study concluded with the determination of an eye-lens protection factor when protection goggles and a ceiling shielding are used. Moreover, the review included the results of studies on active personal dosimeters, their use in IC/IR workplaces, and how they respond to calibration fields, with X-ray standard and pulsed beams. It was shown that APDs are insensitive to backscatter radiation, but some of them could not respond correctly to the very intense pulsed fields (as those next to the patient in interventional practices). The measurements during interventional procedures showed the potential capability of the employment of APDs in hospitals.

Impact of the incorrect use of lead drapes on staff and patient doses in interventional radiology

To evaluate the usefulness of commercially available scatter reduction drapes in mitigating staff exposure in interventional radiology and the potential harmful effects of drape malpositioning in terms of exposure levels to both patients and staff. An anthropomorphic phantom was irradiated on an angiography device under three scenarios: no drape and correct and incorrect drape positioning. Different levels of incorrect drape positioning relative to the field-of-view (FOV) were evaluated: slight, mild and severe. Real-time dosimeter systems (positioned on the operator's eye, chest and thyroid) were used to evaluate accumulative doses and dose rates. Different obstruction levels were evaluated and compared to the observer's perception. Additionally, patient exposure was evaluated for all scenarios using a dose area product (DAP). Up to a mild obstruction, by using the drape a dose reduction of up to 86% was obtained while a severe obstruction produced a 1000% increase in exposure, respectively for all dosimeter positions compared to the use of no drape. A similar order of magnitude was observed for patient exposure. Good agreement was obtained for the observer perception of the FOV obstruction up to 25% of the FOV; for larger obstructions, an overestimate of the obstruction was observed. Patient lead drapes can reduce staff doses in interventional radiology procedures even when mildly malpositioned and obscuring the FOV. Special attention to protective drape positioning is necessary, since the severe obstruction of the FOV results in a large increase in both operator and patient exposure.

Impact of Replacing Old C-Arms on Reducing Radiation Exposure

Fluoroscopy is increasingly used by gastroenterologists for endoscopic procedures such as endoscopic retrograde cholangiopancreatography. Unfortunately, fluoroscopy exposes patients and staff to ionizing radiation, which can cause DNA damage, cell death, genetic defects, and cancer. These adverse effects are more likely to occur with increased exposure time and higher radiation doses; therefore, all efforts to decrease exposure are helpful. In this study, we investigate the impact that updating the C-Arms in our endoscopy unit will have on radiation exposure by comparing ionizing radiation effects of the OEC 9900 Elite to the newer OEC Elite. After replicating the setup of a typical endoscopic retrograde cholangiopancreatography, ionizing radiation and energy were measured at the bedside and the head of the bed with each machine. At both positions, the newer OEC Elite C-Arm emitted less energy and ionizing radiation than the OEC 9900 Elite. Continuous imaging with OEC 9900 Elite emitted 0.12 mSv/h at the head of the bed and 0.49 mSv/h at the bedside, while the OEC Elite only emitted 0.04 mSv/h and 0.14 mSv/h, respectively. These values are measures of radiation-induced cancer risk, otherwise known as stochastic risk. The differences grow more significant when extrapolated to show radiation differences for an average procedure (approximately 8 minutes of fluoroscopy time) and the procedural volume for an entire year. In an effort to use as little radiation as possible, we see that we can significantly reduce radiation exposure to our staff by upgrading from an OEC 9900 Elite to and OEC Elite.

An Intravascular Catheter Bending Recognition Method for Interventional Surgical Robots

Robot-assisted interventional surgery can greatly reduce the radiation received by surgeons during the operation, but the lack of force detection and force feedback is still a risk in the operation which may harm the patient. In those robotic surgeries, the traditional force detection methods may have measurement losses and errors caused by mechanical transmission and cannot identify the direction of the force. In this paper, an interventional surgery robot system with a force detection device is designed and a new force detection method based on strain gauges is proposed to detect the force and infer the bending direction of the catheter in the vessel by using BP neural network. In addition, genetic algorithm is used to optimize the BP neural network, and the error between the calculated results and the actual results is reduced by 37%, which improves the accuracy of catheter bending recognition. Combining this new method with traditional force sensors not only reduces the error caused by the traditional mechanical transmission, but also can detect the bending direction of the catheter in the blood vessel, which greatly improves the safety of the operation.

Estimation of occupational radiation doses in neuroendovascular procedures

To estimate the mean effective dose per procedure with multiple dosimetry, to calculate the annual effective dose to personnel working in neuroendovascular procedures and compared with methods reported in the literature and with national and international limits. The radiation dose to personnel was monitored in 20 procedures classified as diagnostic or therapeutic. During each procedure, the equivalent dose to eyes, thyroid, under and over the lead apron at chest level, hands, gonads and knees was measured with lithium fluoride thermoluminescent dosimeter chips (TLD-100). Estimations of the annual effective dose from different methods found in literature that use one or two dosimeters and from this work were compared. Also, a comparison was made with the safety limits recommended in national and international regulations. Radiation exposure to eyes, thyroid, gonads and knees is relevant to the effective dose, and therefore to the annual effective dose estimations. Personnel position is important, as the performing physician, who is closer to the patient, received the highest dose measured. In particular, this was observed in the equivalent dose received over the apron. However, the equivalent dose to the right eye was higher for neuroanaesthesiologists than for performing physicians due to their position relative to the patient. In general, effective doses estimated using one- and two-dosimeter methods found in the literature were, respectively, lower and higher than those obtained with the ten-dosimeter method in this work. The annual effective doses to personnel estimated with the multiple dosimetry algorithm ranged from 1.3 to 1.5 mSv y^-1and are within the national and international limits.

Investigation of Radiation Dose Estimates and Image Quality Between Commercially Available Interventional Fluoroscopy Systems for Fluoroscopically Guided Interventional Procedures

RATIONALE AND OBJECTIVES

To investigate differences in radiation dose and image quality for single-plane flat-panel-detector based interventional fluoroscopy systems from two vendors using phantom study and clinical procedures.

MATERIALS AND METHODS

AlluraClarityIQ (Philips) and Artis Q (Siemens-Healthineers) interventional fluoroscopy systems were evaluated. Phantom study included comparison of system-reported air-kerma rates (AKR) for clinical protocols with simulated patient thicknesses (20-40 cm). Differences in system-reported radiation dose estimates, cumulative-air-kerma (CAK) and kerma-area-product (KAP), for different clinical procedures were investigated. Subset analysis investigated differences in CAK, KAP and other factors affecting radiation dose when the same patients underwent repeat embolization procedures performed by the same physician on the two different fluoroscopy systems. Two blinded interventional radiologists reviewed image-quality for these procedures using a five-point scale (1-5; 5-best) for five parameters.

RESULTS

Phantom study revealed that air-kerma rates was significantly higher for Artis Q system for 30-40cm of simulated patient thicknesses (p < 0.05). Overall data analysis from 4381 clinical cases revealed significant differences in CAK and KAP for certain procedures (p < 0.05); with significantly lower values for AlluraClarityIQ systems (median CAK lower by: 29%-58%). Subset analysis with 40 patients undergoing repeat embolization procedures on both systems revealed that median CAK and KAP were significantly lower for AlluraClarityIQ systems (p < 0.02) by 45% and 31%, respectively. Image quality scores for AlluraClarityIQ systems were significantly greater (mean difference range for five parameters: 1.3-1.6; p < 0.005).

CONCLUSION

Radiation dose and image quality differences were observed between AlluraClarityIQ and Artis Q systems. AlluraClarityIQ systems showed lower radiation utilization and an increase in subjective perception of image quality.

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 indicate 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.

Occupational hazard of fluoroscopy: An invisible threat to orthopaedic surgeons

The use of fluoroscopy is widespread within different medical specialties. Improper protection may cause significant radiation hazard to medical personnel. To evaluate the concepts on radiation safety and fluoroscopy use among orthopaedic surgeons and to reflect our current training on this issue, a survey was distributed to perform an audit in our department, an academic unit. Twenty-eight orthopaedic surgeons replied. Amongst our participants, 96.4% used a lead apron at all times. Only 33% used a thyroid shield, 67% never used radiation goggles and 96% never used radiation protection gloves. 53.6% and 46.4% of participants position the fluoroscopy incorrectly in the anteroposterior and lateral positions, respectively, during use. There is clearly a need for improved safety amongst orthopaedic surgeons. A literature review was further performed, showing the hazards of fluoroscopy for doctors, including the risk of cataracts, radiation dermatitis, skin cancer and thyroid cancer. Hazards specific to females, including breast cancer risk, and in-utero irradiation of foetus were also thoroughly discussed. Recommendations towards radiation safety and practical measures to reduce fluoroscopy radiation hazard during procedure were made. Education and training to doctors on this invisible hazard is strongly advised.

Self-reported radiation safety behaviors among veterinary specialists and residents performing fluoroscopic procedures on small animals

OBJECTIVE

To describe the radiation safety behaviors of veterinary specialists performing small animal fluoroscopic procedures and examine potential risk factors for these behaviors, including knowledge of radiation risk and training regarding machine operating parameters.

SAMPLE

197 veterinary specialists and residents in training.

PROCEDURES

An electronic questionnaire was distributed to members of the American Colleges of Veterinary Internal Medicine (subspecialties of cardiology and small animal internal medicine), Veterinary Radiology, and Veterinary Surgery.

RESULTS

The overall survey response rate was 6% (240/4,274 email recipients). Of the 240 respondents, 197 (82%) had operated an x-ray unit for a small animal fluoroscopic procedure in the preceding year and fully completed the questionnaire. More than 95% of respondents believed that radiation causes cancer, yet approximately 60% of respondents never wore hand or eye protection during fluoroscopic procedures, and 28% never adjusted the fluoroscopy machine operating parameters for the purpose of reducing their radiation dose. The most common reasons for not wearing eye shielding included no requirement to wear eyeglasses, poor fit, discomfort, and interference of eyeglasses with task performance. Respondents who had received training regarding machine operating parameters adjusted those parameters to reduce their radiation dose during procedures significantly more frequently than did respondents who had not received training.

CONCLUSIONS AND CLINICAL RELEVANCE

On the basis of the self-reported suboptimal radiation safety practices among veterinary fluoroscopy users, we recommend formal incorporation of radiation safety education into residency training programs. All fluoroscopy machine operators should be trained regarding the machine operating parameters that can be adjusted to reduce occupational radiation exposure.

KERMA-AREA PRODUCT, ENTRANCE SURFACE DOSE AND EFFECTIVE DOSE IN ABDOMINAL ENDOVASCULAR ANEURYSM REPAIR

This study aims to evaluate patient radiation dose during fluoroscopically guided endovascular aneurysm repair (EVAR) procedures. Fluoroscopy time (FT) and kerma-area product (KAP) were recorded from 87 patients that underwent EVAR procedures with a mobile C-arm fluoroscopy system. Effective dose (ED) and organs' doses were calculated utilising appropriate conversion coefficients based on the recorded KAP values. Entrance surface dose (ESD) was calculated based on KAP values and technical parameters. The mean FT was 22.7 min (range 6.4-76.8 min), resulting in a mean KAP of 36.6 Gy cm2 (range 2.0-167.8 Gy cm2), a mean ED of 6.2 mSv (range 0.3-28.5 mSv) and a mean ESD of 458 mGy (range 26-2098 mGy). The corresponding median values were 17.4 min, 25.6 Gy cm2, 4.4 mSv and 320 mGy. The threshold of 2 Gy for skin erythema was exceeded in two procedures for a focus-to-skin distance (FSD) of 40 cm and six procedures when an FSD of 30 cm was considered. The highest doses absorbed by the adrenals, kidneys, spleen and pancreas and ranged between 3.7 and 313.3 mGy (average 66.8 mGy), 3.3 and 285.1 mGy (average 60.8 mGy), 1.3 and 111.1 mGy (average 23.7 mGy), 1.1 and 92.1 mGy (average 19.6 mGy), respectively. A wide range of patient doses was reported in the literature. The radiation dose received by the patients was comparative or lower than most of the previously reported values. However, higher doses can be revealed due to the X-ray system's non-optimum use and extended FTs, mainly affected by complex clinical conditions, patients' body habitus and vascular surgeon experience. The large variation of patient doses highlights the potential to optimise the EVAR procedure by considering the balance between the radiation dose and the required image quality. Additional studies need to be conducted in increasing the vascular surgeons' awareness regarding patient dose and radiation protection issues during EVAR procedures.

The use of minimal fluoroscopy for cardiac electrophysiology procedures: A meta-analysis and review of the literature

BACKGROUND

Conventional catheter ablation involves prolonged exposure to ionizing radiation, potentially leading to detrimental health effects. Minimal fluoroscopy (MF) represents a safer alternative, which should be explored. Data on the safety and efficacy of this technique are limited.

HYPOTHESIS

Our hypothesis is that MF is of equal efficacy and safety to conventional catheter ablation with the use of fluoroscopy by performing a meta-analysis of both randomized controlled trials (RCTs) and real-world registry studies.

METHODS

Pubmed and Embase were searched from their inception to July 2020 for RCTs, cohort and observational studies that assessed the outcomes of catheter ablation using a MF technique versus the conventional approach.

RESULTS

Fifteen studies involving 3795 patients were included in this meta-analysis. There was a significant reduction in fluoroscopy and procedural time with no difference in acute success (odds ratio [OR]:0.74, 95% CI: 0.50-1.10, p = .14), long-term success (OR:0.92, 95% CI: 0.65-1.31, p = .38), arrhythmia recurrence (OR:1.24, 95% CI: 0.75-2.06, p = .97) or rate of complications. (OR:0.83, 95% CI: 0.46-1.48, p = .65). Additionally sub-group analysis for those undergoing catheter ablation for atrial fibrillation (AF) did not demonstrate a difference in success or complication rates (OR:0.86, 95% CI: 0.30-2.42, p = .77). Multivariate meta-regression did not identify the presence of moderator variables.

CONCLUSION

This updated meta-analysis demonstrated an overall reduction in procedural and fluoroscopy time for those undergoing a minimal fluoroscopic approach. There was no significant difference in either acute or chronic success rates or complications between a MF approach and conventional approach for the management of all arrhythmias including those undergoing catheter ablation for AF.

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

OBJECTIVE

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.

METHODS

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).

RESULTS

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).

CONCLUSIONS

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.

Occupational Radiation Exposure and Validity of National Dosimetry Registry among Korean Interventional Radiologists

The national dose registry (NDR) contains essential information to help protect radiation workers from radiation-related health risks and to facilitate epidemiological studies. However, direct validation of the reported doses has not been considered. We investigated the validity of the NDR with a personal dosimeter monitoring conducted among Korean interventional radiologists. Among the 56 interventional radiologists, NDR quarterly doses were compared with actively monitored personal thermoluminescent dosimeter (TLD) doses as standard measures of validation. We conducted analyses with participants categorized according to compliance with TLD badge-wearing policies. A correlation between actively monitored doses and NDR doses was low (Spearman ρ = 0.06), and the mean actively monitored dose was significantly higher than the mean NDR dose (mean difference 0.98 mSv) in all participants. However, interventional radiologists who wore badges irregularly showed a large difference between actively monitored doses and NDR doses (mean difference 2.39 mSv), and participants who wore badges regularly showed no apparent difference between actively monitored doses and NDR doses (mean difference 0.26 mSv). This study indicated that NDR data underestimate the actual occupational radiation exposure, and the validity of these data varies according to compliance with badge-wearing policies. Considerable attention is required to interpret and utilize NDR data based on radiation workers’ compliance with badge-wearing policies.

Use of Biological Dosimetry for Monitoring Medical Workers Occupationally Exposed to Ionizing Radiation

Medical workers are the largest group exposed to man-made sources of ionizing radiation. The annual doses received by medical workers have decreased over the last several decades, however for some applications, like fluoroscopically guided procedures, the occupational doses still remain relatively high. Studies show that for some procedures the operator and staff still use insufficient protective and dosimetric equipment, which might cause an underestimation of medical exposures. Physical dosimetry methods are a staple for estimating occupational exposures, although due to the inconsistent use of protection measures, an alternative method such as biological dosimetry might complement the physical methods to achieve a more complete picture. Such methods were used to detect exposures to doses as low as 0.1 mSv/year, and could be useful for a more accurate assessment of genotoxic effects of ionizing radiation in medical workers. Biological dosimetry is usually based on the measurement of the effects present in peripheral blood lymphocytes. Although some methods, such as chromosome aberration scoring or micronucleus assay, show promising results, currently there is no one method recognized as most suitable for dosimetric application in the case of chronic, low-dose exposures. In this review we decided to evaluate different methods used for biological dosimetry in assessment of occupational exposures of medical workers.

Orthopaedic Surgeon Brain Radiation During Fluoroscopy: A Cadaver Model

BACKGROUND

The aims of this study were to quantify exposure of the surgeon's brain to radiation during short cephalomedullary (SC) nailing, to extrapolate lifetime dose, and to determine the effects of personal protective equipment (PPE) on brain dose.

METHODS

Two cadaveric specimens were used: (1) a whole cadaveric body representing the patient, with a left nail inserted to act as the scatter medium, and (2) an isolated head-and-neck cadaveric specimen representing a surgeon, with radiation dosimeters placed in specific locations in the brain. The "patient" cadaver's left hip was exposed in posteroanterior and lateral radiographic planes. Measurements were performed without shielding of the head-and-neck specimen and then repeated sequentially with different PPE configurations. An average surgeon career was estimated to be 40 years (ages 25 to 65 years) with the caseload obtained from the department's billing data.

RESULTS

The mean radiation dose to the surgeon brain without PPE was 3.35 µGy (95% confidence interval [CI]: 2.4 to 4.3) per nail procedure. This was significantly reduced with use of a thyroid collar (2.94 µGy [95% CI: 1.91 to 3.91], p = 0.04). Compared with use of the thyroid collar in isolation, there was no significant additional reduction in radiation when the collar was used with leaded glasses (2.96 µGy [95% CI: 2.15 to 3.76], p = 0.97), with a lead cap (3.22 µGy [95% CI: 2.31 to 4.13], p = 0.55), or with both (2.31 µGy [95% CI: 1.61 to 3.01], p = 0.15). The extrapolated lifetime dose over 40 working years for SC nailing without PPE was 2,146 µGy (95% CI: 1,539 to 2,753), with an effective dose of 21.5 µSv.

CONCLUSIONS

The extrapolated cumulative lifetime radiation to a surgeon's brain from SC nailing based on our institution's workload and technology is low and comparable with radiation during a one-way flight from London to New York. Of note, we studied only one of many fluoroscopy-aided procedures and likely underestimated total lifetime exposure if exposures from other procedures are included. This study also demonstrates that thyroid collars significantly reduce brain dose for this procedure whereas other head/neck PPE such as lead caps appear to have minimal additional effect. This study provides a methodology for future studies to quantify brain dose for other common orthopaedic procedures.

CLINICAL RELEVANCE

This study, based on our institutional data, demonstrates that although the lifetime brain dose from SC nailing is low, thyroid collars significantly reduce this dose further. As such, in accordance with the "as low as reasonably achievable" radiation exposure principle, radiation safety programs and individual surgeons should consider use of thyroid collars in this setting.

Feasibility of dosimetric measurements using Al2O3:C OSL dosimeter during fluoroscopy-guided procedures

This study investigated the feasibility of dosimetric measurements using Al2O3:C optically stimulated luminescence (OSL) dosimeters during fluoroscopy-guided procedures. The linearity and energy dependence of Al2O3:C OSL dosimeters were evaluated, and the air kerma rate at the operator's position was measured. The response of Al2O3:C OSL dosimeters to short, repetitive irradiations was compared to that of long uninterrupted irradiation. The change in response of the Al2O3:C OSL dosimeter under automatic exposure rate control (AERC) was evaluated with the use of various thicknesses of polymethyl-methacrylate (PMMA) plates (15-30 cm). The Al2O3:C OSL dosimeters could detect 5µGy and showed good linearity in doses of ≥10µGy (R²: 0.997-0.999,p< 0.001). The relative response of the Al2O3:C OSL dosimeter normalised to that of 36.8 keV was 0.828-1.101 at the energies investigated (30.6-46.0 keV). The air kerma rate at the operator's position was estimated to be 2.61-7.17µGy min^-1depending on the heights representing different body parts. Repetitive short irradiations had no significant impact on the relative response of the Al2O3:C OSL dosimeters (p> 0.05). Despite a high energy dependence on the low energy beam used in fluoroscopy, the change in relative response of the Al2O3:C OSL dosimeter under AERC was within 5.7% depending on the thickness of the PMMA plates. Dosimetric measurement using Al2O3:C OSL dosimeters for patients and operators is feasible. However, one should be cautious about high standard deviations when measuring small doses of ≤20µGy using Al2O3:C OSL dosimeters. It is essential to perform intensive bleaching before measuring very small doses to minimise pre-irradiation counts.

CONCEPTUAL DESIGN AND PRELIMINARY RESULTS OF A VR-BASED RADIATION SAFETY TRAINING SYSTEM FOR INTERVENTIONAL RADIOLOGISTS

To help minimise occupational radiation exposure in interventional radiology, we conceptualised a virtual reality-based radiation safety training system to help operators understand complex radiation fields and to avoid high radiation areas through game-like interactive simulations. The preliminary development of the system has yielded results suggesting that the training system can calculate and report the radiation exposure after each training session based on a database precalculated from computational phantoms and Monte Carlo simulations and the position information provided by the Microsoft HoloLens headset. In addition, real-time dose rate and cumulative dose will be displayed to the trainee to help them adjust their practice. This paper presents the conceptual design of the overall hardware and software design, as well as preliminary results to combine HoloLens headset and complex 3D X-ray field spatial distribution data to create a mixed reality environment for safety training purpose in interventional radiology.

Rogue cell-like chromosomal aberrations in peripheral blood lymphocytes of interventional radiologists: A case study

We report two cases of interventional radiologists who had been exposed to radiation while performing fluoroscopically-guided interventional procedures (FGIPs), mainly transcatheter arterial chemoembolization, percutaneous catheter drainage, and percutaneous transhepatic biliary drainage procedures, for over 10 years. They had a unique multi-aberrant cell type with not only high numbers of dicentrics and/or centric rings but also excess acentric double minutes, similar to a rogue cell. As revealed in a self-administered questionnaire, they wore personal dosimeters and protective equipment at all times and used shielding devices during interventional fluoroscopy procedures. However, the exposed dose levels derived from cytogenetic dosimetry were much higher than the doses recorded on their personal dosimeters. A large number of unstable and stable chromosomal aberrations that were found in the peripheral blood lymphocytes of these interventional radiologists might be due to repeated and long-term exposure to ionizing radiation while performing FGIPs. Further investigations of chromosomal aberrations in interventional radiologists may improve the understanding of the long-term effects of radiation exposure on medical personnel.

OCCUPATIONAL RADIATION PROCEDURES AND DOSES AMONG NURSES IN SOUTH KOREA

This study investigated occupational radiation procedures and radiation exposures among nurses in South Korea. A total of 530 nurses were surveyed from 2012 to 2013, and the survey data were linked with the dosimetry data. Multiple regression analysis was used to identify the factors associated with radiation dose. The most frequent procedure performed by the nurses was interventional radiology, followed by fluoroscopy and routine X-ray. The average annual effective dose and the cumulative dose were 0.91 mSv and 4.66 mSv, respectively. Characteristics of nurses exposed to high radiation doses were male, completed graduate school or higher, first worked before 2000 and performing interventional procedures, nuclear medicine test and fluoroscopy. Performing nuclear medicine tests and interventional procedures had a significant positive association with high radiation exposure.

Radiation Dose to the Eye Lens Through Radiological Imaging Procedures at the Surgical Workplace During Trauma Surgery

Background: Due to the drastic reduction of the eye lens dose limit from 150 mSv per year to 20 mSv per year since 2018, the prospective investigation of the estimated dose of the eye lens by radiological imaging procedures at the surgical site during trauma surgery in the daily work process was carried out. This was also necessary because, as experience shows, with changes in surgical techniques, there are also changes in the use of radiological procedures, and thus an up-to-date inventory can provide valuable information for the assessment of occupationally induced radiation exposure of surgical personnel under the current conditions. Methods: The eye lens radiation exposure was measured over three months for five trauma surgeons, four hand surgeons and four surgical assistants with personalized LPS-TLD-TD 07 partial body dosimeters Hp (0.07). A reference dosimeter was deposited at the surgery changing room. The dosimeters were sent to the LPS (Landesanstalt für Personendosimetrie und Strahlenschutzausbildung) measuring institute (National Institute for Personal Dosimetry and Radiation Protection Training, Berlin) for evaluation after 3 months. The duration of the operation, occupation (assistant, surgeon, etc.), type of surgery (procedure, diagnosis), designation of the X-ray unit, total duration of radiation exposure per operation and dose area product per operation were recorded. Results: Both the evaluation of the dosimeters by the trauma surgeons and the evaluation of the dosimeters by the hand surgeons and the surgical assistants revealed no significant radiation exposure of the eye lens in comparison to the respective measured reference dosimeters. Conclusions: Despite the drastic reduction of the eye lens dose limit from 150 mSv per year to 20 mSv per year, the limit for orthopedic, trauma and hand surgery operations is well below the limit in this setting.

Reduction of radiation exposure to operating physician and assistant using a real-time auditory feedback dosimeter during femoral artery puncturing: a study on swine model

Background

Real-time dosimeters may create a relatively safer environment not only for the patient but also for the physician and the assistant as well. We propose the use of a real-time radiation measurement dosimeter having auditory feedback to reduce radiation exposure.

Methods

Radiation dose rates were measured for 30 fluoroscopy-guided puncturing procedures of femoral arteries in swine. Fifteen puncturing procedures were performed with real-time radiation measurement dosimeter having auditory feedback and other 15 were performed without auditory feedback dosimeter by an interventional cardiologist with 10 years of experience.

Results

The left body side of the operating physician (38%, p < 0.001) and assistant (25%, p < 0.001) was more exposed as compared to the right body side. Radiation dose rate to the left hand, left arm and left leg were reduced from 0.96 ± 0.10 to 0.79 ± 0.12 mSv/h (17% reduction, p < 0.001), from 0.11 ± 0.02 to 0.07 ± 0.01 mSv/h (36% reduction, p < 0.001) and from 0.22 ± 0.06 to 0.15 ± 0.02 mSv/h (31% reduction, p < 0.001) with the use of auditory feedback dosimeter, respectively. The mean fluoroscopic time was reduced from 4.8 ± 0.43 min to 4.2 ± 0.53 min (p < 0.001). The success rate of performing arterial puncturing was 100%.

Conclusions

The use of auditory feedback dosimeter resulted in reduction in effective dose. The sound beep alerted the physician from the danger of exposure, and this approach induced awareness and protective mindset to the operating physician and assistant.

New Eye Lens Dose Limit: Status of Knowledge in Campania Hospitals

The International Commission on Radiation Protection (ICRP) in 2011 recommended the lowering of the annual eye lens dose limit from 150 mSv/year to 20 mSv/year in order to reduce the risk of X-ray-induced lens opacity in medical staff. The purpose of this study was to assess the status of knowledge of the new eye lens dose limit and of the radioprotection culture among operators. To this end, a questionnaire was administered to physicians, X-ray technicians, and nurses working in five hospitals of the Campania region, Italy. A total of 64 questionnaires were collected in the hospital departments in which procedures involving ionizing radiation were routinely performed. The data analyzed yielded the following results: 12 operators affirmed to know the new eye lens dose limit, 53 operators routinely wore lead aprons, and 23 operators used lead glasses. Four workers performed eye lens dosimetry through specific dosimeters. A significant lack of knowledge of the reduced eye lens dose limit suggests the need to implement radioprotection-training programs aimed at raising awareness about the importance of health care in the workplace and at reducing the risk of radio-induced effects to the eye lens.

Simulation of H p (10) and effective dose received by the medical staff in interventional radiology procedures

Interventional radiology and cardiology are widespread employed techniques for diagnosis and treatment of several pathologies because they avoid the majority of the side-effects associated with surgical treatments, but are known to increase the radiation exposure to patient and operators. In recent years many studies treated the exposure of the operators performing cardiological procedures. The aim of this work is to study the exposure condition of the medical staff in some selected interventional radiology procedures. The Monte Carlo simulations have been employed with anthropomorphic mathematical phantoms reproducing the irradiation scenario of the medical staff with two operators and the patient. A personal dosemeter, put on apron, was modelled for comparison with measurements performed in hospitals, done with electronic dosemeters, in a reduced number of interventional radiology practices. Within the limits associated to the use of numerical anthropomorphic models to mimic a complex interventional procedure, the personal dose equivalent, H _p (10), was evaluated and normalised to the simulated Kerma-Area Product, KAP, value, indeed the effective dose has been calculated. The H _p (10)/KAP_value of the first operator is about 10 μSv/Gy.cm², when ceiling shielding is not used. This value is calculated on the trunk and it varies of +/-30% moving the dosemeter to the waist or to the neck. The effective dose, normalised to the KAP value, varies between 0.03 and 0.4 μSv/Gy.cm². Considering all the unavoidable approximation of this kind of investigations, the comparisons with hospital measurement and literature data showed a good agreement allowing to use of the present results for dosimetric characterisation of interventional radiology procedures.

Radiation exposure of dogs and cats undergoing fluoroscopic procedures and for operators performing those procedures

OBJECTIVE

To evaluate radiation exposure of dogs and cats undergoing procedures requiring intraoperative fluoroscopy and for operators performing those procedures.

SAMPLE

360 fluoroscopic procedures performed at 2 academic institutions between 2012 and 2015.

PROCEDURES

Fluoroscopic procedures were classified as vascular, urinary, respiratory, cardiac, gastrointestinal, and orthopedic. Fluoroscopy operators were classified as interventional radiology-trained clinicians, orthopedic surgeons, soft tissue surgeons, internists, and cardiologists. Total radiation exposure in milligrays and total fluoroscopy time in minutes were obtained from dose reports for 4 C-arm units. Kruskal-Wallis equality of populations rank tests and Dunn pairwise comparisons were used to compare differences in time and exposure among procedures and operators.

RESULTS

Fluoroscopy time (median, 35.80 minutes; range, 0.60 to 84.70 minutes) was significantly greater and radiation exposure (median, 137.00 mGy; range, 3.00 to 617.51 mGy) was significantly higher for vascular procedures than for other procedures. Median total radiation exposure was significantly higher for procedures performed by interventional radiology-trained clinicians (16.10 mGy; range, 0.44 to 617.50 mGy), cardiologists (25.82 mGy; range, 0.33 to 287.45 mGy), and internists (25.24 mGy; range, 3.58 to 185.79 mGy).

CONCLUSIONS AND CLINICAL RELEVANCE

Vascular fluoroscopic procedures were associated with significantly longer fluoroscopy time and higher radiation exposure than were other evaluated fluoroscopic procedures. Future studies should focus on quantitative radiation monitoring for patients and operators, importance of operator training, intraoperative safety measures, and protocols for postoperative monitoring of patients.

Reduction of operator radiation exposure using a passive robotic device during fluoroscopy-guided arterial puncture: an experimental study in a swine model

Background

Vascular interventions imply radiation exposure to the operating physician (OP). To reduce radiation exposure, we propose a novel passive robotic device for fluoroscopy-guided arterial puncturing.

Methods

X-ray dose rates were measured for a total of 30 fluoroscopy-guided puncture femoral arteries in 15 pigs. Fifteen punctures were performed with the device while the other 15 were performed without the device by an interventional cardiologist with 10 years of experience. Parametric t test was used.

Results

The success rate with the device was 100%. Overall, the OP received more radiation (0.41 mSv/h) as compared to the assistant (0.06 mSv/h) (p <  0.001) and, amongst OP’s body parts, hands received more radiation than other body parts (p <  0.001). The radiation dose rate to the OP’s hands during arterial puncturing performed manually without the device was 0.95 ± 0.25 mSv/h whereas it was 0.14 ± 0.006 mSv/h using the device, resulting in an 85% reduction (p <  0.001). For the head, the dose was reduced from 0.16 mSv/h to 0.08 mSv/h (50% reduction, p <  0.001), and for the dominant arm, from 0.12 mSv/h to 0.07 mSv/h (42% reduction, p <  0.001). The fluoroscopy time was reduced from 4.5 ± 0.15 min to 4.3 ± 0.11 min device (p = 0.002).

Conclusions

In a swine model, fluoroscopy time and radiation exposure for the OP puncturing femoral artery were significantly reduced by using the passive robotic device.

2018 ACC/HRS/NASCI/SCAI/SCCT Expert Consensus Document on Optimal Use of Ionizing Radiation in Cardiovascular Imaging: Best Practices for Safety and Effectiveness-A Review for the Cardiac Anesthesiologist

The American College of Cardiology, in collaboration with the American Society of Nuclear Cardiology, Heart Rhythm Society, Mended Hearts, North American Society for Cardiovascular Imaging, Society for Cardiovascular Angiography and Interventions, Society for Cardiovascular Computed Tomography, and Society of Nuclear Medicine and Molecular Imaging, recently published a consensus document recommending best practices for the use of ionizing radiation in cardiovascular medicine. With the increase in number and complexity of catheter-based cardiovascular interventions, cardiothoracic anesthesiologists are being requested to consult and provide care for these patients. This review summarizes the salient portions of the consensus document as it pertains to the anesthesiologist. Radiation exposure for both patients and providers should be minimized to be as low as reasonably achievable. For the anesthesiologist involved in the procedure, the authors recommend wearing protective garments including apron, vest, neck collar, and glasses of at least 0.25-mm lead or lead equivalent. The addition of a portable shield also is strongly recommended. The anesthesiologist should maintain the maximum distance allowable from the x-ray source, remembering that radiation intensity is inversely proportional to the square of the distance from the x-ray source. Monitoring radiation exposure is done best by both collar and under-apron film badge. A 0.5-mm lead-equivalent apron is expected to shield approximately 95% of the radiation. By using these recommendations, the anesthesiologist should be able to keep radiation exposure under 20 mSv per year as recommended by the International Commission on Radiation Protection.