OA135] Current pediatric radiation doses from a computed tomography (CT) dose registry

Abstract

Purpose To summarize data on radiation doses collected from pediatric ( 15 years) CT examinations that can contribute to improving existing reference levels. Methods As part of a US National Institutes of Health (NIH) and Patient Centered Outcomes Resaerch Institute (PCORI) funded study, we created a CT radiation dose registry that includes pediatric ( 15 years) scans from 139 facilities in calendar year 2017. We describe, for separate anatomic regions, median (”target”) and 75th percentile (”benchmark”) values of CT dose index volume (CTDIvol) and dose length product (DLP) for US and European institutions separately. We further stratified pediatric doses by age group into 10 levels. Results Results include 17168 CT scans of the head (65%), chest (11%) abdomen (22%) and chest-abdomen-pelvis (CAP) (2%) performed in children across Europe and the US. In European pediatric scans, the target and benchmark CTDIvol values (in mGy) were: head (21.02 and 33.07), chest (1.51 and 2.30), abdomen (3.06 and 4.42). In US pediatric scans, the benchmark CTDIvol values were: head (22.79 and 30.29), chest (2.48 and 4.61), abdomen (4.63 and 6.19). In European pediatric scans, the target and benchmark DLP values (in mGy-cm) were: head (431.70 and 565.70), chest (38.29 and 63.96), abdomen (114.06 and 162.63). In US pediatric scans, the benchmark DLP values were: head (388.00 and 568.20), chest (64.90 and 144.07), abdomen (191.60 and 296.10). With the exception of head scans, European doses appear to be much lower than US doses. Similar usage of multi-phase scanning in Europe (13%) and the US (12%) does not explain the large differences in DLP. For benchmark chest scans in the US, the dose ranged by age from 2.0 to 6.7 mGy; for Europe 1.7 to 4.6. Similar variations occur in other anatomic regions. Conclusions Dose metrics from a large sample, multi-institution, multi-national registry can contribute to the creation of representative pediatric benchmarks that can be used for dose optimization and inter-institution comparisons. Pediatric doses are generally lower among European institutions compared to US institutions. For both US and European pediatric scans, we generally found a doubling of dose by age within each anatomical region.