Occupational doses to the eye lens in pediatric and adult noncardiac interventional radiology procedures

Abstract

To assess occupational lens exposure in a mixed interventional radiology department, comparing pediatric and adult procedures. To analyze the correlation between the lens dose and the doses measured at the chest and collar level and the kerma-area product (P KA ). Methods: For 17 months, three radiologists performing both pediatric and adult interventions were monitored by means of 14 dosimeters per worker: 12 single-point optically stimulated luminescent (OSL) dosimeters calibrated in terms of H p (0.07) were placed on the inside and outside of two pairs of lead glasses, one for pediatric procedures and one for adult interventions; another whole-body OSL dosimeter calibrated in terms of H p (10) was placed over the thyroid shield; finally, an additional active solid-state dosimeter, also calibrated for H p (10), was worn on the chest, over the apron. Furthermore, a database was created to register the demographic and dosimetric data of the procedures, as well as the name of the radiologist acting as first operator. Results: For the three radiologists, who performed 276-338 procedures/year (20% pediatric), cumulative annual doses to the left bare eye exceeded 20 mSv (21-61 mSv). Considering the glasses' protection, annual doses exceeded 6 mSv (13-48 mSv) for both eyes. No important differences were observed in lens dose per procedure between pediatric and adult interventions (0.16 vs 0.18, 0.12 vs 0.09, and 0.07 vs 0.07 mSv), although lens dose per P KA was 4.1-4.5 times higher in pediatrics (5.8 vs 1.3, 3.3 vs 0.8, and 2.6 vs 0.6 µSv/GyÁcm 2 ) despite a similar use of the ceiling-suspended screen. Lens doses were highly correlated with collar readings (with Pearson coefficients [r] ranging from 0.86 to 0.98) and with chest readings (with r ranging from 0.75 to 0.93). However, slopes of the linear regressions varied greatly among radiologists. Conclusions: There is real risk of exceeding the occupational dose limit to the eye lens in mixed interventional radiology rooms if radiation protection tools are not used properly. Regular monitoring of the lens dose is recommended, given lens exposure might easily exceed 6 mSv/yr. Using a collar dosimeter for this purpose might be suitable if it is preceded by an individualized regression analysis. The same radiation protection measures should be applied to interventional radiologists regardless of whether they are treating pediatric or adult patients.

Assessment of Occupational Exposure to Eye Lens Dosimetry for Interventional Radiology Workers in China During 2017–2019

“…There was an increasing trend in AAELD for the monitored workers in China during 2017-2019 in this study, which is consistent with the increasing trend of the average dose in a US high-volume cancer center from 2012 to 2017 (Bellamy et al 2020), where the current average eye lens dose was higher than before. The maximum annual eye lens dose of 64.48 mSv was comparable with that to interventional cardiology workers in Spain (61.0 mSv) (Morcillo et al 2021;Principi et al 2015), while it was much higher than the maximum expected eye doses for ICs in United Kingdom (21 mSv) (Mairs 2016).…”

Uncertainties in occupational eye lens doses from dosimeters over the apron in interventional practices

“…But other studies describing measurements in clinical practice shows better correlation between measures on chest and on glasses. Alejo et al [24] and Morcillo et al [26] published conversion factors assessed in clinical practice ranging from 0.33 to 1.2 from the over apron at the chest level to the outside glasses H p (0.07), for interventional cardiologists and radiologists. Gracia-Ochoa et al reported correction factors (glasses outside/chest) measured also in clinical practice between 0.35 and 0.7 for different interventional disciplines, finding more consistent factors for chest than for collar [25].…”

“…Using dosimeters on the thyroid collar or on the chest over the apron are more practical options to estimate eye doses and in some situations makes unnecessary a dosimeter close to the eye. There are studies that examine the relationship between the dose measured at the neck or on the chest over the apron with the dose received at eye level by means of Monte Carlo simulations [17], phantom simulations [18][19][20] and measurements in clinical procedures [21][22][23][24][25][26][27], some of them suggesting that accurate correction factors could be operator dependant.…”

Staff eye lens dose in interventional radiology and cardiology in Finland

“…Numerous studies concerning medical staff have emphasized eye lens equivalent dose as the potentially limiting dose quantity for radiation protection, especially with respect to interventional radiologists and cardiologists who are among the most exposed workers [5][6][7][8]. Lens doses exceeding 20 mSv/year [7,9] and even 50 mSv/year [5,10] have been reported, raising concerns that the current ICRP nominal lifetime threshold dose of 0.5 Gy for cataract induction [11] might be exceeded.…”

“…According to ICRP Publication 139, a body dosemeter worn over the apron at collar level on the most exposed side of the interventionalist, provides a reasonable estimation of the equivalent dose to the lens of the eye [1]. Clear correlation between dose readings measured by body dosemeters (H p (10)) at collar or chest height and eye dosemeter H p (3) readings have been reported [6,8], although large differences in the conversion factors between dose quantities were observed [6,15]. For many workers, eye lens dose estimation based on body dosemeter readings (measured over the protective apron) and application of a conversion factor might be adequate to ensure that the eye doses of these workers do not exceed the legal limits [15].…”