Potential occupational exposures in diagnostic and interventional radiology: statistical modeling based on Finnish national dose registry data

Applicability of 'Toolkit for Safety Assessment' tool to interventional radiology using probabilistic risk assessment techniques

Interventional radiology brings extensive benefits to patients. Nevertheless, certain procedures may result in high doses of radiation, leading to health risks to occupationally exposed individuals (OEIs). Therefore, a more comprehensive risk analysis is essential to ensuring safety and minimising radiation exposures for all OEIs. The Toolkit for Safety Assessment (TOKSA) tool performs risk assessments based on the concepts described in 'General Safety Requirements' Part 3 (Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards) and Part 4 (Safety Assessment for Facilities and Activities). This tool was developed based on the 'Ibero-American Forum of Radiological and Nuclear Regulatory Agencies' risk models and can promote the use of the risk assessment processes by OEIs. The aim of this study was to experimentally analyse the applicability of the TOKSA tool in interventional radiology with the use/support of probabilistic risk assessment techniques. The results were used to reduce the risks associated with a hemodynamics room in a hospital in Belo Horizonte, Brazil.

Occupational Doses to Medical Staff Performing or Assisting with Fluoroscopically Guided Interventional Procedures

Background Staff who perform fluoroscopically guided interventional (FGI) procedures are among the most highly radiation-exposed groups in medicine. However, there are limited data on monthly or annual doses (or dose trends over time) for these workers. Purpose To summarize occupational badge doses (lens dose equivalent and effective dose equivalent values) for medical staff performing or assisting with FGI procedures in 3 recent years after accounting for uninformative values and one- versus two-badge monitoring protocol. Materials and Methods Badge dose entries of medical workers believed to have performed or assisted with FGI procedures were retrospectively collected from the largest dosimetry provider in the United States for 49 991, 81 561, and 125 669 medical staff corresponding to years 2009, 2012, and 2015, respectively. Entries judged to be uninformative of occupational doses to FGI procedures staff were excluded. Monthly and annual occupational doses were described using summary statistics. Results After exclusions, 22.2% (153 033 of 687 912) of the two- and 32.9% (450 173 of 1 366 736) of the one-badge entries were judged to be informative. There were 335 225 and 916 563 of the two- and one-badge entries excluded, respectively, with minimal readings in the above-apron badge. Among the two-badge entries, 123 595 were incomplete and 76 059 had readings indicating incorrect wear of the badges. From 2009 to 2015 there was no change in lens dose equivalent values among workers who wore one badge (P = .96) or those who wore two badges (P = .23). Annual lens dose equivalents for workers wearing one badge (median, 6.9 mSv; interquartile range, 3.8213.8 mSv; n = 6218) were similar to those of staff wearing two badges (median, 7.1 mSv; interquartile range, 4.6-11.2 mSv; n = 1449) (P = .18), suggesting a similar radiation environment. Conclusion These workers are among the highest exposed to elevated levels of ionizing radiation, although their occupational doses are within U.S. regulatory limits. This is a population that requires consistent and accurate dose monitoring; however, failure to return one or both badges, reversal of badges, and improper badge placement are a major hindrance to this goal. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Karellas in this issue.

OCCUPATIONAL DOSE AND RADIATION PROTECTION PRACTICE IN UAE: A RETROSPECTIVE CROSS-SECTIONAL COHORT STUDY (2002-2016)

A two-phased retrospective cross-sectional study analysed the occupational dose and radiation protection practice among medical workers in two hospitals in the UAE. Phase 1 evaluated radiation protection practice using a questionnaire, whereas phase 2 assessed the occupational dose. Readings of 952 thermoluminescence dosimeters were analyzed. The result showed 52% of medical workers have a good level of radiation protection practice. Readings of 952 thermoluminescence dosimeters were analyzedAverage annual effective dose per worker ranged from 0.39 to 0.83 mSv. Cardiologists and nurses displayed a higher average of occupational radiation dose compared to other workers. There were no significant correlations between radiation protection practice and hospital, occupation or department. Finally, the occupational dose was within the international and national limits, but the reduction of radiation dose to cardiologist and nurses is essential. Moreover, training is essential to promote radiation safe practice among medical workers.

OCCUPATIONAL EXPOSURE TO EXTERNAL IONISING RADIATION IN TANZANIA (2011-17)

The objectives of this paper were to evaluate the occupational radiation exposure data from 2011 to 2017 and to compare the results with status in 1996-2010 periods. The evaluation was performed in terms of annual collective effective dose, the average annual effective dose, the individual dose distribution ratio and the annual collective effective dose distribution ratio. Irrespective of work category, the results indicate that the average effective dose ranged from 0.64 to 1.55 mSv and broadly comparable to data in the previous analysis. Over seven year period, the maximum annual individual dose was 4 mSv and therefore below the dose limit of 20 mSv y-1. The impact of radiological practice on the exposed population was <1.1 person.Sv. The results demonstrate satisfactory radiation protection conditions at workplaces, a situation which is mainly explained by the existing effective regulatory enforcement and improved workers' awareness.

Comparison of Nonimage- and Fluoroscopy-Guided Interlaminar Epidural Block: A Matched Paired Analysis in the Same Individuals

Background

Although fluoroscopic guidance is recommended highly for more accurate lumbar interlaminar epidural steroid injection (L-ESI), many physicians still use a nonimage-guided approach for L-ESIs. However, because of its associated risk of radiation and increased medical expense, the cost-effectiveness and safety of fluoroscopy-guided ESI have been called into question. The goal of this retrospective matched paired analysis in the same individuals was to assess the effectiveness and prevalence of complications of nonimage-guided L-ESI compared to those of fluoroscopy-guided L-ESI. Methods. Between 2015 and 2016, 94 patients who received both nonimage- and fluoroscopy-guided L-ESIs were analyzed retrospectively. The changes of the numeric rating scale (NRS) in pain intensity and functional outcome and the differences in the number of complications between blind and fluoroscopy-guided L-ESIs in the same individuals were evaluated by a matched paired analysis.

Results

Of the 94 patients, the differences in NRS before and after the procedure were 1.29 (95% confidence interval (CI) = 0.94–1.65) for the nonimage-guided group and 1.64 (95% CI = 1.28–2.01) for the fluoroscopy-guided group (p=0.16). More subjective functional improvement was observed in fluoroscopy-guided L-ESI (57, 60.6%) than in nonimage-guided L-ESI (47, 50.0%) without statistical significance (p=0.16). Nine (9.6%) patients in the nonimage-guided group experienced complications related to the procedure overall compared to 4 (4.3%) in the fluoroscopy-guided group (p=0.27).

Conclusions

In this study, both blind and image-guided L-ESI techniques included similar extents of postprocedural outcomes and complications. Physicians should consider the risks associated with the two different techniques overall and develop ways to individualize the procedure to decrease the risk of complications and improve the positive outcomes of lumbar epidural steroid injections.