AN ASSESSMENT OF THE DOSE REDUCTION OF COMMERCIALLY AVAILABLE LEAD PROTECTIVE GLASSES FOR INTERVENTIONAL RADIOLOGY STAFF

Comparison of shielding effects of over-glasses-type and regular eyewear in terms of occupational eye dose reduction

Given the new recommendations for occupational eye lens doses, various lead glasses have been used to reduce irradiation of interventional radiologists. However, the protection afforded by lead glasses over prescription glasses (thus over-glasses-type eyewear) has not been considered in detail. We used a phantom to compare the protective effects of such eyewear and regular eyewear of 0.07 mm lead-equivalent thickness. The shielding rates behind the eyewear and on the surface of the left eye of an anthropomorphic phantom were calculated. The left eye of the phantom was irradiated at various angles and the shielding effects were evaluated. We measured the radiation dose to the left side of the phantom using RPLDs attached to the left eye and to the surface/back of the left eyewear. Over-glasses-type eyewear afforded good protection against x-rays from the left and below; the average shielding rates on the surface of the left eye ranged from 0.70-0.72. In clinical settings, scattered radiation is incident on physicians' eyes from the left and below, and through any gap in lead glasses. Over-glasses-type eyewear afforded better protection than regular eyewear of the same lead-equivalent thickness at the irradiation angles of concern in clinical settings. Although clinical evaluation is needed, we suggest over-glasses-type Pb eyewear even for physicians who do not wear prescription glasses.

Investigation of scatter radiation intensities in the cardiac catheter laboratory: novel versus traditional shielding solutions

A manufacturer has released a novel shielding solution (NSS): Rampart M1128 and claimed that the personal protective equipment (PPE) can be removed. This study investigates the scatter intensities with the NSS or the traditional shielding solutions (TSS) including the ceiling-suspended screen and the tableside lead drape. Isodose maps were generated by two series of measurements with an anthropomorphic phantom using NSS and TSS. Three survey meters were positioned at different heights to measure the scatter intensities at the eye, chest, and pelvic levels. Additional measurements were made at the primary and secondary operators? locations to evaluate the scatter intensities with different clinical projections. For the main operator positions, the isodose maps showed that NSS could result in a scatter dose that reduced by 80% to 95% compared to the same positions with TSS at the eye and chest levels. The corresponding result at the pelvic level was a reduction of 50%. These reductions should be compared to the additional protection by PPE: up to 80% reduction from lead eyeglasses and up to 95% from protective garments. Considering both operators at clinically relevant LAO projections, NSS resulted in scatter dose that was 80% to 96%, 76% to 96% and 25% to 60% lower than those of the TSS at eye, chest and pelvis levels. The protection of NSS is comparable with that of TSS alongside PPE at the eye but not at the chest and the pelvic levels under the setup of coronary angiography.

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.

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.

Occupational radiation dose to the lens of the eye of medical staff who assist in diagnostic CT scans

PURPOSE

We investigated occupational dose to the lens of the eye for CT-assisting personnel for diagnostic purposes using a radio-photoluminescent glass dosimeter (RPLD) and evaluate compliance with the new equivalent dose limit for the lens of the eye (20 mSv/year). Further, we proposed the implementation of "multiple protective measures" and estimated its effect.

METHOD

An eye lens dosimeter clip was developed specifically to attach RPLDs inside radiation safety glasses in an L-shape. Using a total of six RPLDs attached to the radiation safety glasses, the 3-mm dose-equivalent (Hp(3)) to the lens of the eye for medical staff (n = 11; 6 intensive care physicians, 2 pediatricians, 3 radiological technologists) who assisted patients during CT scan for "diagnostic" purpose (n = 91) was measured. We evaluated the dose reduction efficiencies with radiation safety glasses and bag-valve-mask extension tube. We also estimated the protection efficiency with radiation protection curtain introduced in front of the staff's face via the phantom experiment.

RESULTS

Without wearing radiation safety glasses, Hp(3) to the lens of the eye was greatest for intensive care physicians (0.49 mSv/procedure; allowing 40 procedures to be performed annually), followed by pediatricians (0.30 mSv/procedure; 66 procedures annually) and radiological technologists (0.28 mSv/procedure; 71 procedures annually). Use of each type of protective tools: radiation safety glasses (0.07-mm-Pb), bag-valve-mask extension tube (20 cm) and radiation protective curtain (0.25-mm-Pb), reduced Hp(3) to the lens of the eye by 51%, 31% and 61%, respectively.

CONCLUSION

Intensive care physicians perform most assisted ventilations with the bag-valve-mask during "diagnostic" CT scans, and may exceed the equivalent dose limit for the lens of the eye if radiation safety glasses are not worn. If "multiple protective measures" are implemented, compliance with the equivalent dose limit for the lens of the eye should be achievable without placing significant burdens on physicians or medical institutions.

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.

A multicenter study of radiation doses to the eye lenses of medical staff performing non-vascular imaging and interventional radiology procedures in Japan

PURPOSE

This study aimed to measure the eye lens doses received by physicians and other medical staff participating in non-vascular imaging and interventional radiology procedures in Japan.

MATERIAL AND METHODS

From October 2014 to March 2017, 34 physicians and 29 other medical staff engaged in non-vascular imaging and interventional radiology procedures at 18 Japanese medical facilities. These professionals wore radioprotective lead glasses equipped with small, optically stimulated luminescence dosimeters and additional personal dosimeters at the neck during a 1-month monitoring period. The H_p(3) and the H_p(10) and H_p(0.07) were obtained from these devices, respectively. The monthly H_p(3), H_p(10), and H_p(0.07) for each physician and other medical staff member were then rescaled to a 12-month period to enable comparisons with the revised occupational equivalent dose limit for the eye lens.

RESULTS

Among physicians, the average annual H_p(3) values measured by the small luminescence dosimeters on radioprotective glasses were 25.5 ± 38.3 mSv/y (range: 0.4-166.8 mSv/y) and 9.3 ± 16.6 mSv/y (range: 0.3-82.4 mSv/y) on the left and right sides, respectively. The corresponding values for other medical staff were 3.7 ± 3.1 mSv/y (range: 0.4-10.4 mSv/y) and 3.2 ± 2.7 mSv/y (range: 0.5-11.5 mSv/y), respectively.

CONCLUSIONS

The eye lens doses incurred by physicians and other medical staff who engaged in non-vascular imaging and interventional radiology procedures in Japan were provided. Physicians should wear radioprotective glasses and use additional radioprotective devices to reduce the amount of eye lens doses they receive.

Personal Protective Equipment Availability and Utilization Among Interventionalists

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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