The case for radioprotective eyewear/facewear. Practical implications and suggestions

Radiation safety for pain physicians: principles and recommendations

C-arm fluoroscopy is a useful tool for interventional pain management. However, with the increasing use of C-arm fluoroscopy, the risk of accumulated radiation exposure is a significant concern for pain physicians. Therefore, efforts are needed to reduce radiation exposure. There are three types of radiation exposure sources: (1) the primary X-ray beam, (2) scattered radiation, and (3) leakage from the X-ray tube. The major radiation exposure risk for most medical staff members is scattered radiation, the amount of which is affected by many factors. Pain physicians can reduce their radiation exposure by use of several effective methods, which utilize the following main principles: reducing the exposure time, increasing the distance from the radiation source, and radiation shielding. Some methods reduce not only the pain physician's but also the patient's radiation exposure. Taking images with collimation and minimal use of magnification are ways to reduce the intensity of the primary X-ray beam and the amount of scattered radiation. It is also important to carefully select the C-arm fluoroscopy mode, such as pulsed mode or low-dose mode, for ensuring the physician's and patient's radiation safety. Pain physicians should practice these principles and also be aware of the annual permissible radiation dose as well as checking their radiation exposure. This article aimed to review the literature on radiation safety in relation to C-arm fluoroscopy and provide recommendations to pain physicians during C-arm fluoroscopy-guided interventional pain management.

Radiation safety and knowledge: an international survey of 708 interventional pain physicians

INTRODUCTION

Interventional pain procedures have increased in complexity, often requiring longer radiation exposure times and subsequently higher doses. The practicing physician requires an in-depth knowledge and evidence-based knowledge of radiation safety to limit the health risks to themselves, patients and healthcare staff. The objective of this study was to examine current radiation safety practices and knowledge among interventional pain physicians and compare them to evidence-based recommendations.

MATERIALS AND METHODS

A 49-question survey was developed based on an extensive review of national and international guidelines on radiation safety. The survey was web-based and distributed through the following professional organizations: Association of Pain Program Directors, American Academy of Pain Medicine, American Society of Regional Anesthesia and Pain Medicine, European Society of Regional Anesthesia and Pain Therapy, International Neuromodulation Society, and North American Neuromodulation Society. Responses to radiation safety practices and knowledge questions were evaluated and compared with evidence-based recommendations. An exploratory data analysis examined associations with radiation safety training/education, geographical location, practice type, self-perceived understanding, and fellowship experience.

RESULTS

Of 708 responding physicians, 93% reported concern over the health effects of radiation, while only 63% had ever received radiation safety training/education. Overall, ≥80% physician compliance with evidence-based radiation safety practice recommendations was demonstrated for only 2/15 survey questions. Physician knowledge of radiation safety principles was low, with 0/10 survey questions having correct response rates ≥80%.

CONCLUSION

We have identified deficiencies in the implementation of evidence-based practices and knowledge gaps in radiation safety. Further education and training are warranted for both fellowship training and postgraduate medical practice. The substantial gaps identified should be addressed to better protect physicians, staff and patients from unnecessary exposure to ionizing radiation during interventional pain procedures.

Review of experimental estimates for the protection afforded by eyewear for interventional x-ray staff

This paper attempts to systematise all published experimental results for the dose reduction factor (DRF) offered by leaded eyewear on clinicians performing interventional procedures. We aim to present a comprehensive analysis of the issue and a comparison of the various equipment models at different exposure geometries. The main purpose of the paper is, however, to clarify the best choice for the DRF within the possible diverse contexts and approaches to eye lens dose assessment. Evidence has been obtained that the lowest estimates of DRF are associated with larger scatter incidence angles and that, except for the slightly better performance exhibited by wraparound eyeglasses, there is no real distinction between the DRFs for the different equipment categories. The dataset as a whole confirms that, when measurements for the concerned eyewear model and irradiation conditions are unattainable, assuming DRF = 2 represents an adequately conservative choice. Nonetheless, this value includes only 17% of all results from the literature, whereas their histogram follows a distribution skewed towards higher values, represented by a median equal to 5. Therefore, if more realistic dose reconstructions are necessary, such as for purposes of epidemiological investigations or compensation decisions, the adoption of this central tendency index appears to be more reasonable. The complexity of characterising the DRF behaviour as a function of the various exposure factors reinforces the consideration of a statistical approach to eye lens dose assessment as a viable alternative. In this perspective, assuming for DRF a lognormal distribution with parameters [Formula: see text] and [Formula: see text] which has been verified to satisfactorily approximate the literature data distribution, should be deemed to be an appropriate option.

Strategies to Reduce Radiation Exposure in Electrophysiology and Interventional Cardiology

Clinical diagnosis sometimes involves the use of medical instruments that employ ionizing radiation. However, ionizing radiation exposure is a workplace hazard that goes undetected and is detrimental to patients and staff in the catheterization laboratory. Every possible effort should be made to reduce the amount of radiation, including scattered radiation. Implementing radiation dose feedback may have a role in reducing exposure. In medicine, it is important to estimate the potential biologic effects on, and the risk to, an individual. In general, implantation of cardiac resynchronization devices is associated with one of the highest operator exposure doses due to the proximity of the operator to the radiation source. All physicians should work on the principle of as low as reasonably achievable. Methods for reducing radiation exposure must be implemented in the catheterization laboratory. In this article, we review the available tools to lower the radiation exposure dose to the operator during diagnostic, interventional, and electrophysiological cardiac procedures.

Use of Videofluoroscopy in Zoo Dentistry: Endodontic Procedure in a Tiger

Videofluoroscopy was used as a radiographic technique to visualize a canine tooth during root canal therapy in a Siberian tiger. Videofluoroscopy was useful because the procedure was performed in a zoo setting with no access to an on-site darkroom. The fluoroscopic screen and videotape allowed for immediate viewing of the root canal system.

Radiation exposure to the eyes and thyroid during C-arm fluoroscopy-guided cervical epidural injections is far below the safety limit

Background

The aim of this study was to evaluate radiation exposure to the eye and thyroid in pain physicians during the fluoroscopy-guided cervical epidural block (CEB).

Methods

Two pain physicians (a fellow and a professor) who regularly performed C-arm fluoroscopy-guided CEBs were included. Seven dosimeters were used to measure radiation exposure, five of which were placed on the physician (forehead, inside and outside of the thyroid protector, and inside and outside of the lead apron) and two were used as controls. Patient age, sex, height, and weight were noted, as were radiation exposure time, absorbed radiation dose, and distance from the X-ray field center to the physician.

Results

One hundred CEB procedures using C-arm fluoroscopy were performed on comparable patients. Only the distance from the X-ray field center to the physician was significantly different between the two physicians (fellow: 37.5 ± 2.1 cm, professor: 41.2 ± 3.6 cm, P = 0.03). The use of lead-based protection effectively decreased the absorbed radiation dose by up to 35%.

Conclusions

Although there was no difference in radiation exposure between the professor and the fellow, there was a difference in the distance from the X-ray field during the CEBs. Further, radiation exposure can be minimized if proper protection (thyroid protector, leaded apron, and eyewear) is used, even if the distance between the X-ray beam and the pain physician is small. Damage from frequent, low-dose radiation exposure is not yet fully understood. Therefore, safety measures, including lead-based protection, should always be enforced.

Radiation Safety Perceptions and Practices Among Pediatric Anesthesiologists: A Survey of the Physician Membership of the Society for Pediatric Anesthesia

BACKGROUND

Pediatric anesthesiologists are exposed to ionizing radiation from x-rays on an almost daily basis. Our goal was to determine the culture of safety in which they work and how they adhere to preventative strategies that minimize exposure risk in their daily practice.

METHODS

After Institutional Review Board waiver and approval of the Society for Pediatric Anesthesia's research and quality and safety committees, an electronic e-mail questionnaire was sent to the Society's physician, nontrainee members and consisted of questions specific to provider use of protective lead shielding, the routine use of dosimeters, and demographic information. Univariate analyses were performed using the Wilcoxon rank sum test for ordinal variables, the Fisher exact test for categorical variables, and the Spearman test to analyze correlation between 2 ordinal variables, while a proportional odds logistic regression was used for a multivariable ordinal outcome analysis. P values of <.05 were considered statistically significant.

RESULTS

Twenty-one percent (674/3151) of the surveyed anesthesiologists completed the online questionnaire. Radiation exposure is ubiquitous (98.7%), and regardless of sex, most respondents were either concerned or very concerned about radiation exposure (76.8%); however, women were significantly more concerned than men (proportional odds ratio, 1.66 [95% confidence interval, 1.20-2.31]; P = .002). Despite this and independent of sex, level of concern was not associated with use of a radiation dosimeter (P = .85), lead glasses (odds ratio, 1.07 [95% confidence interval, 0.52-2.39]; P = 1.0), or a thyroid shield (P = .12). Dosimeters were rarely (13%) or never used (52%) and were mandated in only 28.5% of institutions. Virtually none of the respondents had ever taken a radiation safety course, received a personal radiation dose report, notification of their radiation exposure, or knew how many millirem/y was considered safe. Half of the respondents were female, and while pregnant, 73% (151/206) tried to avoid radiation exposure by requesting not to be assigned to cases requiring x-rays. These requests were honored 78% (160/206) of the time.

DISCUSSION

Despite universal exposure to ionizing radiation from x-rays, pediatric anesthesiologists do not routinely adhere to strategies designed to limit the intensity of this exposure and rarely work in institutions in which a culture of radiation safety exists. Our study highlights the need to improve radiation safety education, the need to change the safety culture within the operating rooms and imaging suites, and the need to more fully investigate the utility of dosimeters, lead shielding, and eye safety measures in pediatric anesthesia practice.

Effectiveness of protection strategies for reducing radiation exposure in proceduralists during cardiac catheterization procedures: a systematic review protocol

REVIEW QUESTION

What is the effectiveness of radiation protection strategies for reducing the radiation dose received by the proceduralist during cardiac catheterization procedures?

PROMOTING FLUOROSCOPIC PERSONAL RADIATION PROTECTION EQUIPMENT: UNFAMILIARITY, FACTS AND FEARS

An incomplete understanding of risk can cause inappropriate fear. Personal protective equipment (PPE) offered for the prevention of brain cancer in interventional fluoroscopists (IR-PPE). Similar items are offered for cell-phone use (RF-PPE). Publications on fluoroscopy staff brain cancer and similar papers on cell-phone induced brain cancer were reviewed. An internet safety product search was performed, which resulted in many tens of thousands of hits. Vendor claims for either ionizing radiation or radio frequency products seldom addressed the magnitude of the risk. Individuals and institutions can buy a wide variety of safety goods. Any purchase of radioprotective equipment reduces the funds available to mitigate other safety risks. The estimated cost of averting an actuarial fatal brain cancer appears to be in the order of magnitude $10 000 000-$100 000 000. Unwarranted radiation fears should not drive the radiation protection system to the point of decreasing overall safety.

Predictors of Excess Patient Radiation Exposure During Chronic Total Occlusion Coronary Intervention: Insights From a Contemporary Multicentre Registry

BACKGROUND

High patient radiation dose during chronic total occlusion (CTO) percutaneous coronary intervention (PCI) might lead to procedural failure and radiation skin injury.

METHODS

We examined the association between several clinical and angiographic variables on patient air kerma (AK) radiation dose among 748 consecutive CTO PCIs performed at 9 experienced US centres between May 2012 and May 2015.

RESULTS

The mean age was 65 ± 10 years, 87% of patients were men, and 35% had previous coronary artery bypass graft surgery (CABG). Technical and procedural success was 92% and 90%, respectively. The median patient AK dose was 3.40 (interquartile range, 2.00-5.40) Gy and 34% of the patients received > 4.8 Gy (high radiation exposure). In univariable analysis male sex (P = 0.016), high body mass index (P < 0.001), history of hyperlipidemia (P = 0.023), previous CABG (P < 0.001), moderate or severe calcification (P < 0.001), tortuosity (P < 0.001), proximal cap ambiguity (P = 0.001), distal cap at a bifurcation (P = 0.006), longer CTO occlusion length (P < 0.001), blunt/no blunt stump (P < 0.001), and centre (P < 0.001) were associated with higher patient AK dose. In multivariable analysis high body mass index (P < 0.001), previous CABG (P = 0.005), moderate or severe calcification (P = 0.005), longer CTO occlusion length (P < 0.001), and centre (P < 0.001) were independently associated with higher patient AK dose.

CONCLUSIONS

Approximately 1 in 3 patients who undergo CTO PCI receive high AK radiation dose (> 4.8 Gy). Several baseline clinical and angiographic characteristics can help predict the likelihood of high radiation dose and assist with intensifying efforts to reduce radiation exposure for the patient and the operator.

Radiation Protection for the Fluoroscopy Operator and Staff

OBJECTIVE

The purposes of this article are to review available data regarding the range of protection devices and garments with a focus on eye protection and to summarize techniques for reducing scatter radiation exposure.

CONCLUSION

Fluoroscopy operators and staff can greatly reduce their radiation exposure by wearing properly fitted protective garments, positioning protective devices to block scatter radiation, and adhering to good radiation practices. By understanding the essentials of radiation physics, protective equipment, and the features of each imaging system, operators and staff can capitalize on opportunities for radiation protection while minimizing ergonomic strain. Practicing and promoting a culture of radiation safety can help fluoroscopy operators and staff enjoy long, productive careers helping patients.

A prospective case control comparison of the ZeroGravity system versus a standard lead apron as radiation protection strategy in neuroendovascular procedures

Background and purpose

We aimed to compare the performance of the ZeroGravity (ZG) system (radiation protection system composed by a suspended lead suit) against the use of standard protection (lead apron (LA), thyroid shield, lead eyeglasses, table skirts, and ceiling suspended shield) in neuroangiography procedures.

Materials and methods

Radiation exposure data were prospectively collected in consecutive neuroendovascular procedures between December 2014 and February 2015. Operator No 1 was assigned to the use of an LA (plus lead glasses, thyroid shield, and a 1 mm hanging shield at the groin) while operator No 2 utilized the ZG system. Dosimeters were used to measure peak skin dose for the head, thyroid, and left foot.

Results

The two operators performed a total of 122 procedures during the study period. The ZG operator was more commonly the primary operator compared with the LA operator (85% vs 71%; p=0.04). The mean anterior-posterior (AP), lateral, and cumulative dose area product (DAP) radiation exposure as well as the mean fluoroscopy time were not statistically different between the operators’ cases. The peak skin dose to the head of the operator with LA was 2.1 times higher (3380 vs 1600 μSv), while the thyroid was 13.9 (4460 vs 320 μSv), the mediastinum infinitely (520 vs 0 μSv), and the foot 3.3 times higher (4870 vs 1470 μSv) compared with the ZG operator, leading to an overall accumulated dose 4 times higher. The ratio of cumulative operator received dose/total cumulative DAP was 2.5 higher on the LA operator.

Conclusions

The ZG radiation protection system leads to substantially lower radiation exposure to the operator in neurointerventional procedures. However, substantial exposure may still occur at the level of the lens and thyroid to justify additional protection.

Ionizing radiation-induced cataract in interventional cardiology staff

Background:

The use of ionizing radiation has led to advances in medical diagnosis and treatment.

Objectives:

The purpose of this study was to determine the risk of radiation cataractogenesis in the interventionists and staff performing various procedures in different interventional laboratories.

Patients and Methods:

This cohort study included 81 interventional cardiology staff. According to the working site, they were classified into 5 groups. The control group comprised 14 professional nurses who did not work in the interventional sites. Participants were assigned for lens assessment by two independent trained ophthalmologists blinded to the study.

Results:

The electrophysiology laboratory staff received higher doses of ionizing radiation (17.2 ± 11.9 mSv; P < 0.001). There was a significant positive correlation between the years of working experience and effective dose in the lens (P < 0.001). In general, our findings showed that the incidence of lens opacity was 79% (95% CI, 69.9-88.1) in participants with exposure (the case group) and our findings showed that the incidence of lenses opacity was 7.1% (95% CI:2.3-22.6) with the relative risk (RR) of 11.06 (P < 0.001).

Conclusions:

We believe that the risk of radiation-induced cataract in cardiology interventionists and staff depends on their work site. As the radiation dose increases, the prevalence of posterior eye changes increases.

Derivation and application of dose reduction factors for protective eyewear worn in interventional radiology and cardiology

Doses to the eyes of interventional radiologists and cardiologists could exceed the annual limit of 20 mSv proposed by the International Commission on Radiological Protection. Lead glasses of various designs are available to provide protection, but standard eye dosemeters will not take account of the protection they provide. The aim of this study has been to derive dose reduction factors (DRFs) equal to the ratio of the dose with no eyewear, divided by that when lead glasses are worn. Thirty sets of protective eyewear have been tested in x-ray fields using anthropomorphic phantoms to simulate the patient and clinician in two centres. The experiments performed have determined DRFs from simulations of interventional procedures by measuring doses to the eyes of the phantom representing the clinician, using TLDs in Glasgow, Scotland and with an electronic dosemeter in Gothenburg, Sweden. During interventional procedures scattered x-rays arising from the patient will be incident on the head of the clinician from below and to the side. DRFs for x-rays incident on the front of lead glasses vary from 5.2 to 7.6, while values for orientations similar to those used in the majority of clinical practice are between 1.4 and 5.2. Specialised designs with lead glass side shields or of a wraparound style with angled lenses performed better than lead glasses based on the design of standard spectacles. Results suggest that application of a DRF of 2 would provide a conservative factor that could be applied to personal dosemeter measurements to account for the dose reduction provided by any type of lead glasses provided certain criteria relating to design and consistency of use are applied.

Comparison of fluoroscopic operator eye exposures when working from femoral region, side, or head of patient

Operator radiation exposure is an important occupational hazard compounded over the course of an interventional radiologist's career. This study compared operator radiation dose to the eye and head for different positions around the patient. Compared with cases performed from the femoral region, exposures were 1.8 times higher at the side, and 1.6 times higher at the head, using conventional aprons, table shields, and mobile suspended shields. Exposures were 99% lower when using a suspended personal radiation protection system in all positions. In conclusion, standing at the side or head results in higher head exposures in a conventional setup.

Recommendations for occupational radiation protection in interventional cardiology

The radiation dose received by cardiologists during percutaneous coronary interventions, electrophysiology procedures and other interventional cardiology procedures can vary by more than an order of magnitude for the same type of procedure and for similar patient doses. There is particular concern regarding occupational dose to the lens of the eye. This document provides recommendations for occupational radiation protection for physicians and other staff in the interventional suite. Simple methods for reducing or minimizing occupational radiation dose include: minimizing fluoroscopy time and the number of acquired images; using available patient dose reduction technologies; using good imaging-chain geometry; collimating; avoiding high-scatter areas; using protective shielding; using imaging equipment whose performance is controlled through a quality assurance programme; and wearing personal dosimeters so that you know your dose. Effective use of these methods requires both appropriate education and training in radiation protection for all interventional cardiology personnel, and the availability of appropriate protective tools and equipment. Regular review and investigation of personnel monitoring results, accompanied as appropriate by changes in how procedures are performed and equipment used, will ensure continual improvement in the practice of radiation protection in the interventional suite. These recommendations for occupational radiation protection in interventional cardiology and electrophysiology have been endorsed by the Asian Pacific Society of Interventional Cardiology, the European Association of Percutaneous Cardiovascular Interventions, the Latin American Society of Interventional Cardiology, and the Society for Cardiovascular Angiography and Interventions.

Protective eyewear selection for interventional fluoroscopy

Three protective eyewear models were evaluated to determine effectiveness in reducing radiation dose to a fluoroscopist's eyes. The performance of the protective eyewear was measured using radiation dosimeters in a fluoroscopy suite. An Eyewear Protection Factor was determined for each model in each of three exposure orientations. The protection was strongly influenced by the location of the radiation source. When the source was in front of the fluoroscopist, the lead equivalence was important. When the source was to the side of the fluoroscopist, the cross section of the side shield had a significant influence on protection. Protective eyewear selection needs to include consideration of job task and head orientation to the radiation source as well as the possibility that face shape and eyewear fit may also impact the radiation dose to the eye.

Radiation safety for anesthesiologists

PURPOSE OF REVIEW

To review the recent literature on the implications of occupational radiation exposure in anesthesia practice.

RECENT FINDINGS

Wide variation and lack of reduction in operator doses of medical radiation strongly suggests that more attention must be paid to the factors influencing radiation dose exposure. The eye is likely the most sensitive organ for radiation injury. Radiation-related cataract formation might be a stochastic effect. Operators are strongly advised to use eye protection at all times. Safe medical radiation ophthalmic dose limits are currently under review and are likely to be lowered. Current data do not suggest a significant risk to the fetus for pregnant women working in the interventional radiology suite as long as proper monitoring and radiation safety measures are implemented.

SUMMARY

Radiation is increasingly utilized in medicine for diagnostic and therapeutic procedures. Anesthesia providers may become exposed to unsafe doses while providing high-quality patient care. Understanding of the physical principles, the sources of radiation exposure, the potential risks, and safe practices helps to minimize the exposure risk and its potential deleterious effects to the anesthesia team.

Determination of minimum effective height of transparent radiation face shielding for fluoroscopy

During interventional procedures, the vast majority of scatter radiation originates from the patient and table and travels in all directions in straight lines. Because the operator's head is much higher than the patient and at an angle upward and to the side of the patient (not directly above), the scatter received by the operator's head is projected in an upward angle. Thus a face shield could potentially be lower than the object it is shielding, e.g., below the eyes. This principle may be used as an advantage to design the lowest shield that effectively protects the head while providing optimum vision, appearance, acoustics, low weight, and sense of openness. A flat acrylic plate shield, 0.5 mm Pb equivalence, was suspended vertically in front of a 451P dosimeter. A phantom patient created scatter in an interventional suite while the dosimeter was placed at the level of the crowns of different operators' heads. Many different configurations were tested to determine which ones would provide effective shielding. The results confirmed that the top of the shield may reside several centimeters below the vertical height of the dosimeter (operator's crown), allowing line of sight to monitor above the shield, and still provide effective shielding equivalent to when the dosimeter is positioned directly behind the center of the shield. The image receptor functioned as an effective shield against scatter. Factors increasing the minimum height of effective shielding included shorter operator, opposite oblique projection of image receptor, and shield closer to the face (in horizontal direction).

The risk of radiation exposure to the eyes of the interventional pain physician

It is widely accepted that the use of medical imaging continues to grow across the globe as does the concern for radiation safety. The danger of lens opacities and cataract formation related to radiation exposure is well documented in the medical literature. However, there continues to be controversy regarding actual dose thresholds of radiation exposure and whether these thresholds are still relevant to cataract formation. Eye safety and the risk involved for the interventional pain physician is not entirely clear. Given the available literature on measured radiation exposure to the interventionist, and the controversy regarding dose thresholds, it is our current recommendation that the interventional pain physician use shielded eyewear. As the breadth of interventional procedures continues to grow, so does the radiation risk to the interventional pain physician. In this paper, we attempt to outline the risk of cataract formation in the scope of practice of an interventional pain physician and describe techniques that may help reduce them.

Radiation exposure to the surgeon during open lumbar microdiscectomy and minimally invasive microdiscectomy: a prospective, controlled trial

STUDY DESIGN

This is a prospective in vivo study comparing radiation exposure to the surgeon during 10 minimally invasive lumbar microdiscectomy cases with 10 traditional open discectomy cases as a control.

OBJECTIVE

Radiation exposure to the eye, chest, and hand of the operating surgeon during minimally invasive surgery (MIS) and open lumbar microdiscectomy were measured. The Occupational Exposure Guidelines were used to calculate the allowable number of cases per year from the mean values at each of the 3 sites.

SUMMARY OF BACKGROUND DATA

Fluoroscopy is a source of ionizing radiation and as such, is a potential health hazard with continued exposure during surgery. Presently, radiation exposure to the surgeon during MIS lumbar microdiscectomy is unknown.

METHODS

Radiation exposure to the surgeon (millirads [mR]) per case was measured by digital dosimeters placed at the level of the thyroid/eye, chest, and dominant forearm. Other data collected included operative side and level, side of the surgeon, side of the x-ray source, total fluoroscopy time, and energy output.

RESULTS

The average radiation exposure to the surgeon during open cases was thyroid/eye 0.16 ± 0.22 mR, chest 0.21 ± 0.23 mR, and hand 0.20 ± 0.14 mR. During minimally invasive cases exposure to the thyroid/eye was 1.72 ± 1.52 mR, the chest was 3.08 ± 2.93 mR, and the hand was 4.45 ± 3.75 mR. The difference between thyroid/ eye, chest, and hand exposure during open and minimally invasive cases was statistically significant (P = 0.010, P = 0.013, and P = 0.006, respectively). Surgeons standing in an adjacent substerile room during open cases were exposed to 0.2 mR per case.

CONCLUSION

MIS lumbar microdiscectomy cases expose the surgeon to significantly more radiation than open microdiscectomy. One would need to perform 1623 MIS microdiscectomies to exceed the exposure limit for whole-body radiation, 8720 cases for the lens of the eye, and 11,235 cases for the hand. Standing in a substerile room during x-ray localization in open cases is not fully protective.

Minimising radiation exposure to physicians performing fluoroscopically guided cardiac catheterisation procedures: a review

What is known about radiation exposure to physicians who perform cardiac interventions is reviewed and various factors that affect their exposure are discussed. There are wide variations in the radiation dose (up to 1000-fold) per procedure. Despite extensive improvements in equipment and technology, there has been little or no reduction in dose over time. The wide variation and lack of reduction in operator doses strongly suggests that more attention must be paid to factors influencing the operator dose. Numerous patient, physician and shielding factors influence the operator dose to different degrees. Operators can change some of these factors immediately, at minimal or no cost, with a substantial reduction in dose and potential cancer risk.

Phantom study to determine radiation exposure to medical personnel involved in ERCP fluoroscopy and its reduction through equipment and behavior modifications

OBJECTIVE

The aim of this work is to evaluate the potential radiation exposure to medical personnel by comparing results from phantom studies of two different fluoroscopic units used for ERCP, and to determine which equipment or behavior modification can reduce radiation exposure.

METHODS

Radiation exposures using an opaque tissue equivalent chest phantom with an abdominal insert were performed on a stationary dedicated fluoroscopy unit and a mobile C-arm unit, comparing varying equipment manipulations. Scatter radiation was recorded at 1) the patients' head, 2) where the endoscopist stands, and 3) where the equipment personnel stands.

RESULTS

Radiation exposures were significantly higher for the mobile C-arm unit, revealing a 4160-times greater dosage increase for head and neck and a 8660-times increase for body than the fixed unit. Tower position and vertically stationed lead shields facilitated exposure reduction by means of equipment manipulation. The positioning of the endoscopist away from the right corner of the units also decreased exposure.

CONCLUSIONS

Dedicated stationary fluoroscopy units provide significantly less radiation exposure. Equipment and behavior modification including tower positioning down and vertical shielding are essential for reduction in radiation exposure to medical personnel.

Does the endovascular repair of aortoiliac aneurysms pose a radiation safety hazard to vascular surgeons?

OBJECTIVES

Endovascular aortoiliac aneurysm (EAIA) repair uses substantial fluoroscopic guidance that requires considerable radiation exposure. Doses were determined for a team of three vascular surgeons performing 47 consecutive EAIA repairs over a 1-year period to determine whether this exposure constitutes a radiation hazard.

METHODS

Twenty-nine surgeon-made aortounifemoral devices and 18 bifurcated devices were used. Three surgeons wore dosimeters (1) on the waist, under a lead apron; (2) on the waist, outside a lead apron; (3) on the collar; and (4) on the left ring finger. Dosimeters were also placed around the operating table and room to evaluate the patient, other personnel, and ambient doses. Exposures were compared with standards of the International Commission on Radiological Protection (ICRP).

RESULTS

Total fluoroscopy time was 30.9 hours (1852 minutes; mean, 39.4 minutes per case). Yearly total effective body doses for all surgeons (under lead) were below the 20 mSv/y occupational exposure limit of the ICRP. Outside lead doses for two surgeons approximated recommended limits. Lead aprons attenuated 85% to 91% of the dose. Ring doses and calculated eye doses were within the ICRP exposure limits. Patient skin doses averaged 360 mSv per case (range, 120-860 mSv). The ambient (> 3 m from the source) operating room dose was 1.06 mSv/y.

CONCLUSIONS

Although the total effective body doses under lead fell within established ICRP occupational exposure limits, they are not negligible. Because radiation exposure is cumulative and endovascular procedures are becoming more common, individuals performing these procedures must carefully monitor their exposure. Our results indicate that a team of surgeons can perform 386 hours of fluoroscopy per year or 587 EAIA repairs per year and remain within occupational exposure limits. Individuals who perform these procedures should actively monitor their effective doses and educate personnel in methods for reducing exposure.

Potential biological effects following high X-ray dose interventional procedures

Some interventional procedures can result in very high x-ray doses. Potential biological effects of high x-ray doses are reviewed. Deterministic and stochastic effects in skin, bone, parotid glands, and lung are discussed. Threshold doses for the effects and relevant dosimetric principles are addressed. General principles for minimizing the potential for these effects are presented. Knowledge about these effects and the means to minimize radiation dose can assist the physician in the care of patients undergoing lengthy invasive radiologic procedures.