Significant reduction of radiation exposure to operator and staff during cardiac interventions by analysis of radiation leakage and improved lead shielding

The objectives of this study were to disclose and to reduce occupational radiation leakage in invasive cardiology. Prospectively, we analyzed various dose parameters for 330 coronary procedures. We used a Rando phantom to measure scatter entrance skin air kerma to the operator (S-ESAK-O) during fluoroscopy for all standard tube angulations, and to plot isodose lines for 0°/0°-posterior anterior angulation. The patient’s measured dose area product due to diagnostic catheterization and elective percutaneous transluminal coronary angioplasty was 6.2 and 10.4 Gycm2, which represents 11% and 13% of currently typical values, respectively. With use of 0.5- and 1.0-mm overcouch and undercouch shielding, it was possible to reduce the mean of 4,686 nSv/Gycm2 to 677 and 277 nSv/Gycm2, respectively. Closure of radiation leakage up to 897 μSv/hour at the operator’s gonadal height (80 to 105 cm), not heretofore described, was achieved by an additional 1.0-mm, lead-equivalent undercouch-top and overcouch-flap adjacent to the table, down to a S-ESAK-O/dose area product level of 47.5 nSv/Gycm2. With use of a 0.5-mm lead apron, collar, glasses, foot-switch shield and 1.0-mm lead cover around the patient’s thighs, the operator received a mean S-ESAK-O of 8.5, while his forehead, eyes, thyroid, chest, gonads, and hands were exposed to 68.2, 1.2, 1.2, 1.2, 0.8, and 58.2 nSv/Gycm2, respectively. In conclusion, radiation-attenuating intervention techniques and improved lead protection can effectively contribute to a new state of the art in invasive cardiology, with reduction of operator radiation exposure to 0.8% of typical S-ESAK-O levels in advanced catheterization laboratories.