Purpose or Case Report: From NCRP Report 184, to (1) provide summary data from diagnostic medical radiation exposure in children compared with adults and (2) identify challenges and needs with such reporting.
Methods & Materials: NCRP Scientific Committee 4-9 (composed of experts in pediatric and adult and diagnostic, interventional, and therapeutic imaging) recently concluded a 10 yr update on NCRP 160 to now include US per capita medical radiation exposure data in children. Pediatric (2016 US census for <18 yr =74,000,000; ICRP age categories used) sources included published peer review articles (~150), IMV, and SCORCH from 2006-2016. Effective dose (E), collective E (S), and average individual E (E_us) (results are minimally rounded) from ionizing radiation were determined based on ICRP 103 coefficients. Comparison data from adults were obtained from Medicare B, IMV, VA, several other agency reports and published peer review articles.
Results: Annual pediatric medical radiation S is 21,500 person-Sv, 3% of total (all ages) medical radiation S (755,000 person-Sv). Pediatric medical radiation E_us is 0.3 mSv. Pediatric medical radiation S was 9% of total with the remaining 91% from background exposure (vs 51% from background in adults, assuming background E_us 3.0 mSv). Modality use for children: radiography 86%, CT 9.5%, fluoroscopy 3%, nuclear imaging 1%, interventional 0.5%. Contributions to medical radiation S in children: CT 84%, radiography 6%, interventional 4%, remainder < 3%. 5-7% of total (all ages) CT volume was pediatric (previously understood as ~10%). Pediatric CT frequency: head 55%, AP 25%, spine 10%, others < 5% with radiation exposure contributions for CT: AP 51%, head 32%, spine 10%. Challenges in the analyses included limited data on procedure numbers especially for different age classifications, effects of ongoing dose reduction techniques, limitations in effective dose estimation, current changes in patterns of use for some modalities (e.g. decrease trends for nuclear medicine, fluoroscopy), and data predominantly from academic practices. There is no baseline from NCRP 160 for comparison.
Conclusions: NCRP 184 report provides data on current pediatric medical radiation exposure and modality use. There are large uncertainties and gaps. Future projects could provide trend information for medical radiation exposures from which dose management could be linked or attributed and should include organ doses, multimodality national registry data and reporting of quality metrics in addition to exposure based data.