Achievable radiation reduction during pediatric cardiac catheterization: How low can we go?

Abstract

To assess the effectiveness of radiation-reduction measures implemented during pediatric catheterization, and provide data on the radiation doses for common interventional and diagnostic procedures, indexed to body weight. Ionizing radiation exposure must be minimized to "as low as reasonably achievable," by instituting radiation-limiting techniques and knowledge of expected radiation exposure. Radiation-reduction measures included pulsed-fluoroscopy at 7.5 pulses/second (0.032-0.045 µGy/pulse), an air-gap magnification technique for children<20 kg, operator awareness, and additional exposure reduction techniques through projection optimization. Radiation doses for procedures performed between 2007 through 2014 were retrospectively reviewed, including dose area product (DAP) and DAP/kg of body weight for 25 procedural types. Median doses were compared with those previously published from other large centers and multi-institutional databases and assessed for changes over time. Reviewed were 5,196 cases, which included 2,819 interventional, 710 endomyocardial biopsies and 1,667 diagnostic studies, documenting a significant difference in exposure between various procedures and body weights. The absolute exposure was significantly greater in larger children (e.g., for ductal closure median DAP/kg: 17 µGy*m2/kg 10-20 kg children vs. 37 µGy*m2 /kg for those>30 kg, P<0.001). Dose exposure using radiation-reduction techniques were the lowest reported in the literature for all procedure types compared (e.g. median DAP for pulmonary valvuloplasty 163 µGy*m2 vs. 405 to 1,230 µGy*m2 reported by 3 large centers). Reduction of fluoroscopy acquisition to 7.5 pulses/second nearly halved radiation exposure (P<0.001). Implementing a radiation dose reduction and awareness program can lead to documented reduction in exposure, across a variety of procedures performed by multiple operators.