Estimation of effective radiation dose for physicians and staff members in contrast angiocardiography

Abstract

Objective: The goal of this study was to estimate the effective radiation dose for the physicians and staff members in contrast angiocardiography. Design: The study design was a quasi-experimental, random assignment. Setting: A medical center in Jordan that specializes in cardiology and routinely applies fluoroscopy and contrast angiocardiography was the study setting. Participants: Subjects included 235 radiation workers. Outcome Measures: Outcome measures included thermoluminescent dosimeter measurements of radiation dose to the skin and whole body over the lead apron, as well as dose to the whole body under the lead apron. Intervention: The period of this study was 6 years (1990 to 1995). Researchers distributed 1880 thermoluminescent dosimeters (TLDs) to 235 radiation workers during this period. The TLDs were positioned on the trunk of each worker between the waist and shoulder, which is the area of the body with the highest exposure rate. The study included results from 65% of the participants; 35% were excluded because analysis of the collected data indicated that in 14.5% of the participants, the TLDs were positioned incorrectly (TLDs specified for under apron were positioned over collar and vice versa), and 20.5% of the participants rarely or never wore the TLDs issued to them from the National Radiation Protection Laboratory. Results: The results show that the values of effective dose obtained by the proposed method are in reasonable agreement with other previously published methods. The mean annual effective dose is 2.5 ± 2.6 millisievert, with a maximum of 16.2 millisievert. The values of mean and maximum effective doses represent approximately 12.5% and 81% of the annual effective radiation dose limit suggested by the International Commission on Radiological Protection. Conclusions: The use of 2 dosimeters, one to measure the dose transmitted through the lead apron and another to sample the dose at the neck, will allow for an estimate of effective dose in reasonable agreement with other published methods. The proposed method is developed from conservative assumptions that result in a slightly higher effective dose than those that result from applying a correction factor for a single-collar dosimeter. (Heart Lung® 2000;29:417-23.)