Determining the Rate of Change in Exposure to Ionizing Radiation From CT Scans: A Database Analysis From One Hospital

Abstract

Cancer risks associated with radiation from CT procedures have recently received increased attention. An important question is whether the combined impact of CT volume and dose reduction strategies has reduced radiation exposure to adult patients undergoing CT examinations. The aim of this study was to determine differences in radiation exposure from 2008 to 2012 to patients receiving CT scans of the abdomen, head, sinus, and lumbar spine at a midwestern academic medical center that implemented dose reduction strategies. Data were collected from two internal data sets from 2008 to 2012 for general medicine and intensive care unit patients. These data were used to calculate annual CT volume, rate, average effective dose, radiation exposure, and estimated cancer risk. A 37% reduction in abdominal CT volume was found from 2008 to 2012. However, no volume reductions were found for CT examinations of the head or lumbar spine, and the decrease in sinus imaging was minimal. Dose reduction strategies resulted in 30% to 52% decreases in radiation exposure for the targeted body areas. The combined reduction in volume and dose per procedure reduced estimated induced cancers by 63%. Exposure to ionizing radiation from these examinations was reduced at one institution because of reduced volumes of procedures and the reduction of each procedure's effective dose through new protocols and technologies. Although both the volume reduction and dose reduction strategies contributed to the reduced exposure, it seems that investments in implementing the protocols and new technology had the greatest effect on future cancer risk.