Risk for radiation-induced cataract for staff in interventional cardiology: is there reason for concern?

EYE LENS DOSIMETRY WITHIN THE CARDIAC CATHETERISATION LABORATORY-ARE ANCILLARY STAFF BEING FORGOTTEN?

Eye lens doses have been widely explored for interventional clinicians, however, data for ancillary staff is limited. Eye doses have been measured using a headband technique for clinicians, specialist registrars, nurses and radiographers working in a cardiac catheterisation laboratory in a UK hospital. Workload was found to be significantly higher for ancillary staff, and consequently, despite the absolute monthly collar doses and other indicators such as eye dose/KAP and eye dose/procedure being highest for clinicians, our study found there was no significant difference in the monthly eye dose readings between the clinicians and nurses (p = 0.82), and clinicians and radiographers (p = 0.72). The average eye dose/collar dose ratios were 0.71 and 0.61 for cardiologists and SPRs, but ratios above one were found for nurses and radiographers. This work expands on the eye dose data available for ancillary staff and demonstrates that eye dosimetry for these workers should not be overlooked.

ESTABLISHMENT OF DETAILED EYE MODEL OF ADULT CHINESE MALE AND DOSE CONVERSION COEFFICIENTS CALCULATION UNDER NEUTRON EXPOSURE

The human eye lens is sensitive to radiation. ICRP-118 publication recommended a reduction of the occupational annual equivalent dose limit from 150 to 20 mSv, averaged over defined periods of 5 y. Therefore, it is very important to build a detailed eye model for the accurate dose assessment and radiation risk evaluation of eye lens. In this work, a detailed eye model was build based on the characteristic anatomic parameters of the Chinese adult male. This eye model includes seven main structures, which are scleral, choroid, lens, iris, cornea, vitreous body and aqueous humor. The lens was divided into sensitive volume and insensitive volume based on different cell populations. The detailed eye model was incorporated into the converted polygon-mesh version of the Chinese reference adult male whole-body surface model. After the incorporation, dose conversion coefficients for the eye lens were calculated for neutron exposure at AP, PA and LAT geometries with Geant4, the neutron energies were from 0.001 eV to 10 MeV. The calculated lens dose coefficients were compared with those of ICRP-116 publication. Significant differences up to 97.47% were found at PA geometry. This could mainly be attributed to the different geometry characteristic of eye model and parameters of head in different phantom between the present work and ICRP-116 publication.

Radiation Exposure Among Scrub Technologists and Nurse Circulators During Cardiac Catheterization: The Impact of Accessory Lead Shields

OBJECTIVES

This study was performed to determine if the use of an accessory lead shield is associated with a reduction in radiation exposure among staff members during cardiac catheterization.

BACKGROUND

Accessory lead shields that protect physicians from scatter radiation are standard in many catheterization laboratories, yet similar shielding for staff members is not commonplace.

METHODS

Real-time radiation exposure data were prospectively collected among nurses and technologists during 764 consecutive catheterizations. The study had 2 phases: in phase I (n = 401), standard radiation protection measures were used, and in phase II (n = 363), standard radiation protection measures were combined with an accessory lead shield placed between the staff member and patient. Radiation exposure was reported as the effective dose normalized to dose-area product (E_DAP).

RESULTS

Use of an accessory lead shield in phase II was associated with a 62.5% lower E_DAP per case among technologists (phase I: 2.4 [4.3] μSv/[mGy × cm²] × 10^-5; phase II: 0.9 [2.8] μSv/[mGy × cm²] × 10^-5; p < 0.001) and a 63.6% lower E_DAP per case among nurses (phase I: 1.1 [3.1] μSv/[mGy × cm²] × 10^-5; phase II: 0.4 [1.8] μSv/[mGy × cm²] × 10^-5; p < 0.001). By multivariate analysis, accessory shielding remained independently associated with a lower E_DAP among both technologists (34.2% reduction; 95% confidence interval: 20.1% to 45.8%; p < 0.001) and nurses (36.4% reduction; 95% confidence interval: 19.7% to 49.6%; p < 0.001).

CONCLUSIONS

The relatively simple approach of using accessory lead shields to protect staff members during cardiac catheterization was associated with a nearly two-thirds reduction in radiation exposure among nurses and technologists.

Radiation Risk to the Fluoroscopy Operator and Staff

OBJECTIVE

Recent articles discussing cases of brain cancer in interventionalists have raised concerns regarding the hazards of occupational exposure to ionizing radiation. We review the basics of radiation dose and the potential radiation effects, particularly as they pertain to the operator. Then we present the data regarding the risk of each type of radiation effect to the fluoroscopy operator and staff, with special attention on cancer induction, radiation-induced cataracts, and the pregnant operator.

CONCLUSION

Although the evidence overwhelmingly shows that exposure to higher doses of radiation carries a risk of cancer and tissue reactions, the risks of chronic exposure to low-level radiation are less clear. Many studies examining occupational exposure to radiation fail to show an increased risk of stochastic effects of radiation, but the positive results raise concern that the studies are underpowered to consistently detect the small risk. The lack of information in these studies about radiation doses and adherence to radiation protection further confound their interpretation. Large prospective studies of populations with occupational exposure to low-level radiation might clarify this issue. More clearly established are the risks of radiation to the fetus and the risk of cataracts in interventional cardiologists and interventional radiologists. Interventionalists can mitigate these risks by following established radiation safety practices.

Radiation-associated lens changes in the cardiac catheterization laboratory: Results from the IC-CATARACT (CATaracts Attributed to RAdiation in the CaTh lab) study

OBJECTIVE

To examine the relationship between occupational exposure to ionizing radiation and the prevalence of lens changes in interventional cardiologists (ICs) and catheterization laboratory ("cath-lab") staff.

BACKGROUND

Exposure to ionizing radiation is associated with the development of lens opacities. ICs and cath-lab staff can receive high doses of ionizing radiation without protection, and may thus be at risk for lens opacity formation.

METHODS

We conducted a cross-sectional study at an interventional cardiology conference. Study participants completed a questionnaire pertaining to occupational exposure to radiation and potential confounders for the development of cataracts, followed by slit-lamp examination and grading of lens findings.

RESULTS

A total of 117 attendees participated in the study, including 99 (85%; 49 ± 11 years-old; 82% male) with occupational exposure to ionizing radiation and 18 (15%; 39 ± 12 years-old; 61% male) unexposed controls. The prevalence of overall cortical and posterior subcapsular lens changes (including subclinical findings) was higher in exposed participants compared with controls (47 vs. 17%, P = 0.015). Occupational exposure and age over 60 were independent predictors of lens changes (odds ratio [95% CI]: 6.07 [1.38-43.45] and 7.72 [1.60-43.34], respectively). The prevalence of frank opacities was low and similar between the two groups (14 vs. 6%, P = 0.461). Most lens findings consisted of subclinical changes in the periphery of the lens without impact on visual acuity.

CONCLUSIONS

Compared with unexposed controls, ICs and cath-lab staff had a higher prevalence of lens changes that may be attributable to ionizing radiation exposure. While most of these changes were subclinical, they are important due to the potential to progress to clinical symptoms, highlighting the importance of minimizing staff radiation exposure.

Eye Lens Radiation Exposure in Greek Interventional Cardiology Article

The lens of the eye is one of the radiosensitive tissues of the human body; if exposed to ionizing radiation can develop radiation-induced cataract at early ages. This study was held in Greece and included 44 Interventional Cardiologists (ICs) and an unexposed to radiation control group of 22 persons. Of the note, 26 ICs and the unexposed individuals underwent special eye examinations. The detected lens opacities were classified according to LOCS III protocol. Additionally, the lens doses of the ICs were measured using eye lens dosemeters. The mean dose to the lenses of the ICs per month was 0.83 ± 0.59 mSv for the left and 0.35 ± 0.38 mSv for the right eye, while the annual doses ranged between 0.7 and 11 mSv. Regarding the lens opacities, the two groups did not differ significantly in the prevalence of either nuclear or cortical lens opacities, whereas four ICs were detected with early stage subcapsular sclerosis. Though no statistically difference was observed in the cohort, the measured doses indicate that the eye doses received from the ICs can be significant. To minimize the radiation-induced risk at the eye lenses, the use of protective equipment and appropriate training on this issue is highly recommended.

A multiple methods approach: radiation associated cataracts and occupational radiation safety practices in interventionalists in South Africa

Ionising radiation is a modality used in diagnostic and therapeutic medicine. The technology has improved and resulted in lower dose exposure but there has been an escalation in the quantity of procedures, their duration and complexity. These factors have meant increased occupational radiation exposure for interventionalists. Ionising radiation exposure can have detrimental health effects and includes radiation skin burns, various carcinomas, genetic and chromosomal aberrations and cataractogenesis of the lenses of the eye. The lenses of the eye are of the most radiosensitive organs and the risk of cataracts is high despite low radiation dose exposures. The use of personal protective equipment (PPE) is a method that can be used to mitigate the risk for developing lens opacifications. The consistent and effective utilisation of PPE is marred by availability, proper fit and ease of use when performing procedures. Radiation safety training is imperative to enforce a culture of radiation safety among interventionalists. The aim of this study was to quantify and describe cataracts among South African interventionalists and to understand their radiation safety practices. For this purpose, a cross sectional study was designed using multiple methods. A survey was conducted to determine the demographics and the risk factors of doctors exposed to radiation to doctors not exposed. The radiation workload and radiation safety practices of interventionalists were explored. Both groups had slit lamp examinations. The data were analysed analytically and a regression model developed looking at the outcomes and the risk factors. Qualitative in-depth interviews and group interviews were conducted to explore the perceptions of interventionalists regarding radiation safety. Deductive and inductive thematic analysis was done. Interdisciplinary research is challenging but offers tremendous opportunity for exploring and tackling complex issues related to securing a safe radiation work environment.

The current status of eye lens dose measurement in interventional cardiology personnel in Thailand

Workers involved in interventional cardiology procedures receive high eye lens doses if radiation protection tools are not properly utilized. Currently, there is no suitable method for routine measurement of eye dose. In Thailand, the eye lens equivalent doses in terms of Hp(3) of the interventional cardiologists, nurses, and radiographers participating in interventional cardiology procedures have been measured at 12 centers since 2015 in the pilot study. The optically stimulated luminescence (OSL) dosimeter was used for measurement of the occupational exposure and the eye lens dose of 42 interventional cardiology personnel at King Chulalongkorn Memorial Hospital as one of the pilot centers. For all personnel, it is recommended that a first In Light OSL badge is placed at waist level and under the lead apron for determination of Hp(10); a second badge is placed at the collar for determination of Hp(0.07) and estimation of Hp(3). Nano Dots OSL dosimeter has been used as an eye lens dosimeter for 16 interventional cardiology personnel, both with and without lead-glass eyewear. The mean effective dose at the body, equivalent dose at the collar, and estimated eye lens dose were 0.801, 5.88, and 5.70 mSv per year, respectively. The mean eye lens dose measured by the Nano Dots dosimeter was 8.059 mSv per year on the left eye and 3.552 mSv per year on the right eye. Two of 16 interventional cardiologists received annual eye lens doses on the left side without lead glass that were higher than 20 mSv per year, the new eye lens dose limit as recommended by ICRP with the risk of eye lens opacity and cataract.

The effects of simulating a realistic eye model on the eye dose of an adult male undergoing head computed tomography

In head computed tomography, radiation upon the eye lens (as an organ with high radiosensitivity) may cause lenticular opacity and cataracts. Therefore, quantitative dose assessment due to exposure of the eye lens and surrounding tissue is a matter of concern. For this purpose, an accurate eye model with realistic geometry and shape, in which different eye substructures are considered, is needed. To calculate the absorbed radiation dose of visual organs during head computed tomography scans, in this study, an existing sophisticated eye model was inserted at the related location in the head of the reference adult male phantom recommended by the International Commission on Radiological Protection (ICRP). Then absorbed doses and distributions of energy deposition in different parts of this eye model were calculated and compared with those based on a previous simple eye model. All calculations were done using the Monte Carlo code MCNP4C for tube voltages of 80, 100, 120 and 140 kVp. In spite of the similarity of total dose to the eye lens for both eye models, the dose delivered to the sensitive zone, which plays an important role in the induction of cataracts, was on average 3% higher for the sophisticated model as compared to the simple model. By increasing the tube voltage, differences between the total dose to the eye lens between the two phantoms decrease to 1%. Due to this level of agreement, use of the sophisticated eye model for patient dosimetry is not necessary. However, it still helps for an estimation of doses received by different eye substructures separately.

Editorial: ERCP-Related Radiation Cataractogenesis: Is It Time to Be Concerned?

With the growing number of fluoroscopic guided endoscopic procedures, radiation-related risk needs to be further assessed. Recent evidence indicates that radiation cataractogenesis occurs at a lower dose threshold than previously believed. While body aprons and thyroid shields are well-established standard protection during fluoroscopy, ocular safety and the use of protective eyewear are not as well defined. This prospective study answered two important questions: Does the standard body dosimeter provide an accurate ocular dosimetry? And what is the time of fluoroscopy needed to warrant using lens protection? It also raises the question whether current guidelines need to be updated.

Assessment of the occupational eye lens dose for clinical staff in interventional radiology, cardiology and neuroradiology

In accordance with recommendations by the International Commission on Radiological Protection, the current European Basic Safety Standards has adopted a reduced occupational eye lens dose limit of 20 mSv yr^-1. The radiation safety implications of this dose limit is of concern for clinical staff that work with relatively high dose x-ray angiography and interventional radiology. Presented in this work is a thorough assessment of the occupational eye lens dose based on clinical measurements with active personal dosimeters worn by staff during various types of procedures in interventional radiology, cardiology and neuroradiology. Results are presented in terms of the estimated equivalent eye lens dose for various medical professions. In order to compare the risk of exceeding the regulatory annual eye lens dose limit for the widely different clinical situations investigated in this work, the different medical professions were separated into categories based on their distinct work pattern: staff that work (a) regularly beside the patient, (b) in proximity to the patient and (c) typically at a distance from the patient. The results demonstrate that the risk of exceeding the annual eye lens dose limit is of concern for staff category (a), i.e. mainly the primary radiologist/cardiologist. However, the results also demonstrate that the risk can be greatly mitigated if radiation protection shields are used in the clinical routine. The results presented in this work cover a wide range of clinical situations, and can be used as a first indication of the risk of exceeding the annual eye lens dose limit for staff at other medical centres.

Estimating head and neck tissue dose from x-ray scatter to physicians performing x-ray guided cardiovascular procedures: a phantom study

Physicians performing x-ray guided interventional procedures have a keen interest in radiation safety. Radiation dose to tissues and organs of the head and neck are of particular interest because they are not routinely protected by wearable radiation safety devices. This study was conducted to facilitate estimation of radiation dose to tissues of the head and neck of interventional physicians based on the dose recorded by a personal dosimeter worn on the left collar. Scatter beam qualities maximum energy and HVL were measured for 40 scatter beams emitting from an anthropomorphic patient phantom. Variables of the scatter beams included scatter angle (35° and 90°), primary beam peak tube potential (60, 80, 100, and 120 kVp), and 5 Cu spectral filter thicknesses (0-0.9 mm). Four reference scatter beam qualities were selected to represent the range of scatter beams realized in a typical practice. A general radiographic x-ray tube was tuned to produce scatter-equivalent radiographic beams and used to simultaneously expose the head and neck of an anthropomorphic operator phantom and radiochromic film. The geometric relationship between the x-ray source of the scatter-equivalent beams and the operator phantom was set to mimic that between a patient and physician performing an invasive cardiovascular procedure. Dose to the exterior surface of the operator phantom was measured with both 3 × 3 cm² pieces of film and personal dosimeters positioned at the location of the left collar. All films were scanned with a calibrated flatbed scanner, which converted the film's reflective density to dose. Films from the transverse planes of the operator phantom provided 2D maps of the dose distribution within the phantom. These dose maps were normalized by the dose at the left collar, providing 2D percent of left collar dose (LCD) maps. The percent LCD maps were overlain with bony anatomy CT images of the operator phantom and estimates of percent LCD to the left, right and whole brain, brain stem, lenses of the eyes, and carotid arteries were calculated. Per expectation, results indicated greater percent dose to superficial versus deep tissues and increasing percent dose to deep tissues with increasing scatter-equivalent beam energy and HVL. The results enable estimation of the scatter dose to tissues of the head and neck of interventional physicians based on occupational dose measured by a personal dosimeter worn at the collar outside the protective apron.

Occupational Radiation Exposure of Anesthesia Providers: A Summary of Key Learning Points and Resident-Led Radiation Safety Projects

Anesthesia providers are frequently exposed to radiation during routine patient care in the operating room and remote anesthetizing locations. Eighty-two percent of anesthesiology residents (n = 57 responders) at our institution had a "high" or "very high" concern about the level of ionizing radiation exposure, and 94% indicated interest in educational materials about radiation safety. This article highlights key learning points related to basic physical principles, effects of ionizing radiation, radiation exposure measurement, occupational dose limits, considerations during pregnancy, sources of exposure, factors affecting occupational exposure such as positioning and shielding, and monitoring. The principle source of exposure is through scattered radiation as opposed to direct exposure from the X-ray beam, with the patient serving as the primary source of scatter. As a result, maximizing the distance between the provider and the patient is of great importance to minimize occupational exposure. Our dosimeter monitoring project found that anesthesiology residents (n = 41) had low overall mean measured occupational radiation exposure. The highest deep dose equivalent value for a resident was 0.50 mSv over a 3-month period, less than 10% of the International Commission on Radiological Protection occupational limit, with the eye dose equivalent being 0.52 mSv, approximately 4% of the International Commission on Radiological Protection recommended limit. Continued education and awareness of the risks of ionizing radiation and protective strategies will reduce exposure and potential for associated sequelae.

Hand Surgery and Fluoroscopic Eye Radiation Dosage: A Prospective Pilot Comparison of Large Versus Mini C-Arm Fluoroscopy Use

Background: The purpose of this study is to (1) perform a prospective pilot comparison of the impact of large versus mini C-arm fluoroscopy on resultant eye radiation exposure and (2) test the hypothesis that the use of either modality during routine hand surgery does not exceed the current recommended limits to critical eye radiation dosage. Methods: Over a 12-month period, eye radiation exposure was prospectively measured by a board-certified hand surgeon using both large and mini C-arm fluoroscopy. For each modality, accumulated eye radiation dosage was measured monthly, while fluoroscopic radiation output was recorded, including total exposure time and dose rate. Results: A total of 58 cases were recorded using large C-arm and 25 cases using mini C-arm. Between the 2 groups, there was not a significant difference with total exposure time (P = .88) and average dose rate per case (P = .10). With the use of either modality, average monthly eye radiation exposure fell within the undetectable range (<30 mrem), significantly less than the current recommended limit of critical eye radiation (167 mrem/month). Conclusions: The impact of various fluoroscopic sources on eye radiation exposure remains relatively unexplored. In this study, the minimal detectable eye radiation dosages observed in both groups were reliably consistent. Our findings suggest that accumulated eye radiation dosage, from the use of either fluoroscopic modality, does not approach previously reported levels of critical radiation loads.

[Investigation of Scattered Radiation Reduction Effect by Use of Collimator Cover Covered with Leaded Sheet in Angiography Equipment]

The purpose of this study was to investigate the effect of scattered radiation reduction to medical staff by attaching the leaded sheet on the collimator cover of the angiography equipment. Ambient dose equivalent was measured to compare the rate of scattered radiation reduction between with and without the leaded sheet. Shielding effect was confirmed for scattered radiation in all directions, especially 27% of shielding ratio in the head and neck area when angiography equipment installed with small detector, and more than 40% of shielding ratio when adjusting a cut portion of leaded sheet to the field size. However, it decreased when the dose area product meter was not attached. Therefore, our proposed leaded sheet can reduce radiation dose to medical staff during angiographic and interventional procedures.

Radiobiology in Cardiovascular Imaging

The introduction of ionizing radiation in medicine revolutionized the diagnosis and treatment of disease and dramatically improved and continues to improve the quality of health care. Cardiovascular imaging and medical imaging in general, however, are associated with a range of radiobiologic effects, including, in rare instances, moderate to severe skin damage resulting from cardiac fluoroscopy. For the dose range associated with diagnostic imaging (corresponding to effective doses on the order of 10 mSv [1 rem]), the possible effects are stochastic in nature and largely theoretical. The most notable of these effects, of course, is the possible increase in cancer risk. The current review addresses radiobiology relevant to cardiovascular imaging, with particular emphasis on radiation induction of cancer, including consideration of the linear nonthreshold dose-response model and of alternative models such as radiation hormesis.

Changing Patterns in the Performance of Fluoroscopically Guided Interventional Procedures and Adherence to Radiation Safety Practices in a U.S. Cohort of Radiologic Technologists

OBJECTIVE

Information is limited on changes over time in the types of fluoroscopically guided interventional procedures performed and associated radiation safety practices used by radiologic technologists.

MATERIALS AND METHODS

Our study included 12,571 U.S. radiologic technologists who were certified for at least 2 years in 1926-1982 and who reported in a 2012-2013 survey that they ever performed or assisted with fluoroscopically guided interventional procedures. They completed a mailed questionnaire in 2013-2014 describing their detailed work practices for 21 fluoroscopically guided interventional procedures and associated radiation safety practices from the 1950s through 2009.

RESULTS

Overall, the proportion of technologists who reported working with therapeutic fluoroscopically guided interventional procedures, including percutaneous coronary interventions, increased over time, whereas the proportion of technologists who worked with diagnostic fluoroscopically guided interventional procedures, including diagnostic cardiovascular catheterization and neuroangiographic procedures, decreased. We also observed substantial increases in the median number of times per month that technologists worked with diagnostic cardiovascular catheterizations and percutaneous coronary interventions. In each time period, most technologists reported consistently (≥ 75% of work time) wearing radiation monitoring badges and lead aprons during fluoroscopically guided interventional procedures. However, fewer than 50% of the technologists reported consistent use of thyroid shields, lead glasses, and room shields during fluoroscopically guided interventional procedures, even in more recent time periods.

CONCLUSION

This study provides a detailed historical assessment of fluoroscopically guided interventional procedures performed and radiation safety practices used by radiologic technologists from the 1950s through 2009. Results can be used in conjunction with badge dose data to estimate organ radiation dose for studies of radiation-related health risks in radiologic technologists who have worked with fluoroscopically guided interventional procedures.

EYE LENS EXPOSURE TO MEDICAL STAFF PERFORMING ELECTROPHYSIOLOGY PROCEDURES: DOSE ASSESSMENT AND CORRELATION TO PATIENT DOSE

The purpose of this study was to assess the patient exposure and staff eye dose levels during implantation procedures for all types of pacemaker therapy devices performed under fluoroscopic guidance and to investigate potential correlation between patients and staff dose levels. The mean eye dose during pacemaker/defibrillator implementation was 12 µSv for the first operator, 8.7 µSv for the second operator/nurse and 0.50 µSv for radiographer. Corresponding values for cardiac resynchronisation therapy procedures were 30, 26 and 2.0 µSv, respectively. Significant (p < 0.01) correlation between the eye dose and the kerma-area product was found for the first operator and radiographers, but not for other staff categories. The study revealed eye dose per procedure and eye dose normalised to patient dose indices for different staff categories and provided an input for radiation protection in electrophysiology procedures.

Reduction of Fluoroscopy Time and Radiation Dosage During Catheter Ablation for Atrial Fibrillation

Radiofrequency catheter ablation has become the treatment of choice for atrial fibrillation (AF) that does not respond to antiarrhythmic drug therapy. During the procedure, fluoroscopy imaging is still considered essential to visualise catheters in real-time. However, radiation is often ignored by physicians since it is invisible and the long-term risks are underestimated. In this respect, it must be emphasised that radiation exposure has various potentially harmful effects, such as acute skin injury, malignancies and genetic disease, both to patients and physicians. For this reason, every electrophysiologist should be aware of the problem and should learn how to decrease radiation exposure by both changing the setting of the system and using complementary imaging technologies. In this review, we aim to discuss the basics of X-ray exposure and suggest practical instructions for how to reduce radiation dosage during AF ablation procedures.

InterCardioRisk: a novel online tool for estimating doses of ionising radiation to occupationally-exposed medical staff and their associated health risks

Those working in interventional cardiology and related medical procedures are potentially subject to considerable exposure to x-rays. Two types of tissue of particular concern that may receive considerable doses during such procedures are the lens of the eye and the brain. Ocular radiation exposure results in lens changes that, with time, may progress to partial or total lens opacification (cataracts). In the early stages, such opacities do not result in visual disability; the severity of such changes tends to increase progressively with dose and time until vision is impaired and cataract surgery is required. Scattered radiation doses to the eye lens of an interventional cardiologist in typical working conditions can exceed 34 μGy min^-1 in high-dose fluoroscopy modes and 3 μGy per image during image acquisition (instantaneous rate values) when radiation protection tools are not used. A causal relation between exposure to ionising radiation and increased risk of brain and central nervous system tumours has been shown in a number of studies. Although absorbed doses to the brain in interventional cardiology procedures are lower than those to the eye lens by a factor between 3.40 and 8.08 according to our simulations, doses to both tissues are among the highest occupational radiation doses documented for medical staff whose work involves exposures to x-rays. We present InterCardioRisk, a tool featuring an easy-to-use web interface that provides a general estimation of both cumulated absorbed doses experienced by medical staff exposed in the interventional cardiology setting and their estimated associated health risks. The tool is available at http://intercardiorisk.creal.cat.

Ionizing radiation exposure in interventional cardiology: current radiation protection practice of invasive cardiology operators in Lithuania

Ionizing radiation management is among the most important safety issues in interventional cardiology. Multiple radiation protection measures allow the minimization of x-ray exposure during interventional procedures. Our purpose was to assess the utilization and effectiveness of radiation protection and optimization techniques among interventional cardiologists in Lithuania. Interventional cardiologists of five cardiac centres were interviewed by anonymized questionnaire, addressing personal use of protective garments, shielding, table/detector positioning, frame rate (FR), resolution, field of view adjustment and collimation. Effective patient doses were compared between operators who work with and without x-ray optimization. Thirty one (68.9%) out of 45 Lithuanian interventional cardiologists participated in the survey. Protective aprons were universally used, but not the thyroid collars; 35.5% (n  =  11) operators use protective eyewear and 12.9% (n  =  4) wear radio-protective caps; 83.9% (n  =  26) use overhanging shields, 58.1% (n  =  18)-portable barriers; 12.9% (n  =  4)-abdominal patient's shielding; 35.5% (n  =  11) work at a high table position; 87.1% (n  =  27) keep an image intensifier/receiver close to the patient; 58.1% (n  =  18) reduce the fluoroscopy FR; 6.5% (n  =  2) reduce the fluoro image detail resolution; 83.9% (n  =  26) use a 'store fluoro' option; 41.9% (N  =  13) reduce magnification for catheter transit; 51.6% (n  =  16) limit image magnification; and 35.5% (n  =  11) use image collimation. Median effective patient doses were significantly lower with x-ray optimization techniques in both diagnostic and therapeutic interventions. Many of the ionizing radiation exposure reduction tools and techniques are underused by a considerable proportion of interventional cardiology operators. The application of basic radiation protection tools and techniques effectively reduces ionizing radiation exposure and should be routinely used in practice.

OCCUPATIONAL DOSE ASSESSMENT IN INTERVENTIONAL CARDIOLOGY IN SERBIA

The objective of this work is to assess the occupational dose in interventional cardiology in a large hospital in Belgrade, Serbia. A double-dosimetry method was applied for the estimation of whole-body dose, using thermoluminescent dosemeters, calibrated in terms of the personal dose equivalent Hp(10). Besides the double-dosimetry method, eye dose was also estimated by means of measuring ambient dose equivalent, H*(10), and doses per procedure were reported. Doses were assessed for 13 physicians, 6 nurses and 10 radiographers, for 2 consequent years. The maximum annual effective dose assessed was 4.3, 2.1 and 1.3 mSv for physicians, nurses and radiographers, respectively. The maximum doses recorded by the dosemeter worn at the collar level (over the apron) were 16.8, 11.9 and 4.5 mSv, respectively. This value was used for the eye lens dose assessment. Estimated doses are in accordance with or higher than annual dose limits for the occupational exposure.

Radiation Exposure During Fluoro-Assisted Direct Anterior Total Hip Arthroplasty

BACKGROUND

Utilization of the direct anterior approach (DAA) for total hip arthroplasty (THA) has increased in the last decade with fluoroscopy often used to confirm implant position, leg length, and offset. Radiation exposure thresholds around 800 mGy are published for the risk of cataracts. We hypothesized that surgeon eye exposure during fluoro-assisted DAA total hip arthroplasty would be well below these published thresholds.

METHODS

Three experienced orthopedic surgeons performed 30 consecutive fluoro-assisted DAA THAs. During each procedure, the surgeon wore a helmet-mounted dosimeter. After 30 consecutive cases, the dosimeters were analyzed. A chart review was then completed to obtain fluoroscopic data saved for each individual case including fluoroscopic time, total radiation dose, and radiation tech experience.

RESULTS

Fluoroscopic data were available for 89 of 90 cases (98.8%). Surgeon 1 had an average fluoroscopic time of 18.51 seconds, radiation dose of 2.396 mGy, and tech experience of 13.06 years. Surgeon 2 had an average fluoroscopic time of 15.63 seconds, radiation dose of 2.139 mGy, and tech experience of 23.69 years. Surgeon 3 had an average fluoroscopic time of 11.06 seconds, radiation dose of 1.462 mGy, and tech experience of 16.03 years. The dosimeter results were 8, 5, and <1 mrem, respectively, for each surgeon. The mean total radiation dose per case for all surgeons was 2.00 mGy (±1.31), and there was no correlation between radiation dose and radiologic tech experience (0.089, P > .05) or radiation dose and patients' body mass index (0.260, P = .014).

CONCLUSIONS

Each surgeon would need to perform >300,000 DAA THAs to exceed the 800-mGy cataract threshold dose. The decision to wear protective glasses should be at the surgeon's discretion; however, the findings in this study show a very low radiation dose to the surgeon's eye regardless of radiologic tech experience or patient's body mass index.

Characteristics of interventional cardiologists and their work practices for the study on radiation-induced lens opacities based on the methodology developed by ELDO-preliminary results

Preliminary results of the Polish epidemiology study on eye lens opacities among interventional cardiologists (ICs), based on the methodology proposed by ELDO (epidemiological studies of radio-induced cataracts in interventional cardiologists and radiologists: methodology implementation), are presented. The aim of the study is to test the hypothesis concerning the excess risk of cataract in the group of ICs. The first results concern the study population characteristics, including the most important confounding factors for cataract, as well as a detailed description of the work practices in interventional cardiology needed in order to reconstruct the cumulative eye lens dose. The data from 69 ICs and 23 controls collected based on the general medical questionnaire and the occupational questionnaire (for ICs only) were analyzed. The mean age of ICs and of the control group was 41 and 44, respectively, while the mean duration of work for exposed physicians was 9 years. The analysis of the data from the occupational questionnaire concerning the procedures performed, the use of various access routes, as well as radiation protection tools (eye lens glasses, ceiling suspended transparent shield, etc.) are also presented. On the basis of this information and additional assumptions about the doses per procedure (as well as reduction factors for various types of radiation measures), the cumulative doses to the eye lens of ICs were evaluated. They ranged up to 1.55 Sv and 0.4 Sv for left and right eye, respectively; however, the dose to only 3% of ICs exceeded the new threshold for development of eye lens opacities (0.5 Gy) proposed by the ICRP.

Attenuation assessment of medical protective eyewear: the AVEN experience

The goal of this paper is to test the attenuation capability of seven models of protective eyewear used in routine clinical practice. Scattered radiation from a standard patient was simulated by using a water tank located over the treatment couch of a GE Innova 3100 x-ray angiography system. Seven protective eyewear models were tested using an anthropomorphic phantom mimicking the first operator. At each test, 4 thermoluminiscent dosimeters were placed on the phantom (respectively in front of the protective eyewear, under the eyewear, on the left earpiece and at chest level) in order to have an eyewear-independent reference. A test session without glasses was also acquired. Each model was tested with standard posterior-anterior (PA) projections and the two most common protective eyewear were tested using LAO90° and LAO45°CRA30° projections. A worst-case scenario was created to be sure of having an upper limit for the assessment of eyewear attenuation in routine clinical practice. In PA projections, the absolute attenuation value ranged between 71% and 81%, while relative attenuation between dose measured at eye lens and that measured at eyewear earpiece ranged from 67% to 85%. The slightly wider range was probably due to scatter radiation variability; anyway, differences are still included in the variable uncertainty of experimental measurements. It is worth noting that #3 eyewear model (the one without lateral protection) allows an attenuation similar to that of #5 eyewear model (with 0.5 mm lead lateral protection) in LAO90° and LAO45°CRA30° projections. Despite the experimental limitations, a description of the radiation properties of protective eyewear concerning radiation attenuation can be useful to rely on protection devices which can be used in routine clinical practice.

Reducing absorbed dose to eye lenses in head CT examinations: the effect of bismuth shielding

The eye lens is considered to be among the most radiosensitive human tissues. Brain CT scans may unnecessarily expose it to radiation even if the area of clinical interest is far from the eyes. The aim of this study is to implement a bismuth eye lens shielding system for Head-CT acquisitions in these cases. The study is focused on the assessment of the dosimetric characteristics of the shielding system as well as on its effect on image quality. The shielding system was tested in two set-ups which differ for distance ("contact" and "4 cm" Set up respectively). Scans were performed on a CTDI phantom and an anthropomorphic phantom. A reference set up without shielding system was acquired to establish a baseline. Image quality was assessed by signal (not HU converted), noise and contrast-to-noise ratio (CNR) evaluation. The overall dose reduction was evaluated by measuring the CTDIvol while the eye lens dose reduction was assessed by placing thermoluminescent dosimeters (TLDs) on an anthropomorphic phantom. The image quality analysis exhibits the presence of an artefact that mildly increases the CT number up to 3 cm below the shielding system. Below the artefact, the difference of the Signal and the CNR are negligible between the three different set-ups. Regarding the CTDI, the analysis demonstrates a decrease by almost 12 % (in the "contact" set-up) and 9 % (in the "4 cm" set-up). TLD measurements exhibit an eye lens dose reduction by 28.5 ± 5 and 21.1 ± 5 % respectively at the "contact" and the "4 cm" distance. No relevant artefact was found and image quality was not affected by the shielding system. Significant dose reductions were measured. These features make the shielding set-up useful for clinical implementation in both studied positions.

Occupational eye lens doses in interventional cardiology. A multicentric study

New European regulation regarding radiological protection of workers and more specifically the new occupational dose limit for the eye lens recently reduced to 20 mSv yr(-1) may affect interventional cardiologists. This paper presents a set of measurements of occupational doses performed in five interventional cardiology centres and then compared with the new dose limit. The measurement of occupational doses was performed over the apron at chest level using electronic dosemeters recording H p(10). In one of the centres, scatter dose at goggles was also measured with optically stimulated luminescence dosemeters calibrated in terms of H p(0.07). An average H p(10) over the apron of 46 μSv/procedure was measured for cardiologists. Lower doses were noted in other professionals like second cardiologists, nurses or anaesthetists. Procedures for valvular and other structural heart diseases involved the highest occupational doses, averaging over 100 μSv/procedure. Important differences in occupational doses among centres may be indicative of different radiation protection habits. The new occupational dose limit for the eye lens is likely to be exceeded by those among the interventionalists who do not use protection tools (ceiling suspended screen and/or goggles) even with standard workloads.

Staff lens doses in interventional urology. A comparison with interventional radiology, cardiology and vascular surgery values

The purpose of this work is to evaluate radiation doses to the lens of urologists during interventional procedures and to compare them with values measured during interventional radiology, cardiology and vascular surgery. The measurements were carried out in a surgical theatre using a mobile C-arm system and electronic occupational dosimeters (worn over the lead apron). Patient and staff dose measurements were collected in a sample of 34 urology interventions (nephrolithotomies). The same dosimetry system was used in other medical specialties for comparison purposes. Median and 3rd quartile values for urology procedures were: patient doses 30 and 40 Gy cm(2); personal dose equivalent Hp(10) over the apron (μSv/procedure): 393 and 848 (for urologists); 21 and 39 (for nurses). Median values of over apron dose per procedure for urologists resulted 18.7 times higher than those measured for radiologists and cardiologists working with proper protection (using ceiling suspended screens) in catheterisation laboratories, and 4.2 times higher than the values measured for vascular surgeons at the same hospital. Comparison with passive dosimeters worn near the eyes suggests that dosimeters worn over the apron could be a reasonable conservative estimate for ocular doses for interventional urology. Authors recommend that at least the main surgeon uses protective eyewear during interventional urology procedures.

Measurement of occupational doses of ionising radiation to the lens of the eyes of interventional radiologists

Currently, there exists no standardised method for monitoring radiation doses to the eye lens. This investigation aimed to determine the optimum method for monitoring the eye doses for interventional radiologists. Three interventional radiologists were issued with a series of dosimeters to wear during their routine work. These dosimeters were worn at defined positions on the body and the absorbed dose to each position was measured. It was confirmed that the dose received to the thyroid collar followed an apparently well-defined relationship to the dose recorded on the forehead, which is representative of the dose to the lens of the eye. It was also confirmed that, as hypothesised, the dose to the left eye was universally greater than to the right, although by varying factors. It was concluded that the use of dosimeters attached to the inside arms of protective eyewear is the optimum solution for eye lens dosimetry. It was also concluded that, when used with a dose conversion factor which corroborates existing literature, dosimeters attached to the outside of a thyroid collar yield sufficiently accurate results for use in routine dosimetry programmes.

An assessment of nursing staffs' knowledge of radiation protection and practice

Although the exposure to nursing staff is generally lower than the allowable radiation worker dose limits, awareness and overcoming fears of radiation exposure is essential in order to perform routine activities in certain departments. Furthermore, the nursing staff, whether they are defined as radiation workers or not, must be able to respond to any radiological emergencies and provide care to any patient affected by radiation. This study aims to gauge the awareness of radiation safety among the nursing staff at a major hospital in different departments and recommend if further radiation safety training is required. A prospective multiple choice questionnaire was distributed to 200 nurses in 9 different departments. The questionnaire tested knowledge that would be taught at a basic radiation safety course. 147 nurses (74%) completed the survey with the average score of 40%. Furthermore, 85% of nurses surveyed felt there was a need for radiation safety training in their respective departments to assist with day to day work in the department. An increase in radiation safety materials that are specific to each department is recommended to assist with daily work involving radiation. Moreover, nursing staff that interact with radiation on a regular basis should undertake radiation safety courses before beginning employment and regular refresher courses should be made available thereafter.

Correlation between scatter radiation dose at height of operator's eye and dose to patient for different angiographic projections

Studies have reported cases of radiation-induced cataract among cardiology professionals. In view of the evidence of epidemiological studies, the ICRP recommends a new threshold for opacities and a new radiation dose to eye lens limit of 20mSv per year for occupational exposure. The aim of this paper is to report scattered radiation doses at the height of the operator's eye in an interventional cardiology facility without considering radiation protection devices and to correlate these values with different angiographic projections and operational modes. Measurements were taken in a cardiac laboratory with an angiography X-ray system equipped with flat-panel detector. PMMA plates of 30×30×5cm were used with a thickness of 20cm. Measurements were taken in two fluoroscopy modes (low and normal, 15pulses/s) and in cine mode (15frames/s). Four angiographic projections were used: anterior posterior; lateral; left anterior oblique caudal (spider); and left anterior oblique cranial, with a cardiac protocol for patients weighing between 70 and 90kg. Measurements of phantom entrance dose rate and scatter dose rate were performed with two Unfors Xi plus detectors. The detector measuring scatter radiation was positioned at the usual distance of the cardiologist's eyes during working conditions. There is a good linear correlation between the kerma area product and scatter dose at the lens. Experimental correlation factors of 2.3, 12.0, 12.2 and 17.6μSv/Gycm2 were found for different projections. PMMA entrance dose rates for low and medium fluoroscopy and cine modes were 13, 39 and 282mGy/min, respectively, for AP projection.

Reducing radiation in chronic total occlusion percutaneous coronary interventions

The field of percutaneous intervention for chronic total occlusion (CTO) has enjoyed significant innovations in the recent years. Novel techniques and technologies have revolutionized the field and have resulted in considerably higher success rates even in patients with high anatomical complexity. Successful CTO recanalization is associated with significant clinical benefits, such as the improvement of angina and quality of life, reduced rates of surgical revascularization, improvement of left ventricular function and decreased mortality rates. However, complex CTO procedures often require prolonged x-ray exposure which have been associated with adverse long term outcomes.

Guideline Implementation: Radiation Safety

Because radiologic technology is used in a variety of perioperative procedures and settings, it is essential for perioperative RNs to be knowledgeable of the risks related to radiation and the ways to adequately protect patients and health care providers from unintended radiation exposure. The updated AORN "Guideline for radiation safety" provides guidance on preventing injury from ionizing radiation exposure during therapeutic, diagnostic, and interventional procedures. This article focuses on key points of the guideline to help perioperative personnel practice radiation safety. The key points address the requirements for an organization's radiation safety program, measures used to keep radiation exposure as low as reasonably achievable, proper handling and testing of radiation protection devices, and considerations for protecting employees and patients who are pregnant and who will be exposed to radiation. Perioperative RNs should review the complete guideline for additional information and for guidance when writing and updating policies and procedures.