Purpose or Case Report: Pediatric body CT is an invaluable imaging tool. There is increasing focus to manage and monitor radiation dose estimations from CT, especially in children. One approach, set forth by the International Commission on Radiological Protection (IRCP) is the establishment of diagnostic reference levels (DRLs). Consensus DRLs have recently been established for body CT in Canada, and are in the final stages in Europe (Diagnostic Reference Levels for Pediatric Imaging-PiDRL), but not in the US. Region-specific determinations (which may vary) are worth assessing. The purpose of this study was two-fold: to define what exists in literature for US pediatric body CT DRLs, and to define what metrics should be considered for inclusion in DRL determination.
Methods & Materials: Library services (using MEDLINE) guided a search in peer-reviewed journals (2006-2016) for US studies and terms DRLs, computed tomography dose index (CTDI), dose length product (DLP), size-specific dose estimate (SSDE), or pediatric CT. These were filtered for specifically discussing dose of pediatric body CT (chest, abdomen, pelvis, or abdomen/pelvis). Studies discussing dose from phantom data or from specialized exams (CT angiogram, dual energy CT) were excluded. Articles were compared to DRL requirements for the 9 criteria used in the Canadian CT Survey National Diagnostic Reference Levels and the 14 criteria from PiDRL (Table1). Studies were also assessed on 15 criteria we proposed as essential to include for pediatric body CT dose for the eventual establishment of DRLs in the US.
Results: Of the 182 papers which included our search terms, only 7 papers met criteria for inclusion. None included all the criteria set forth in the Canadian and European recommendations for DRLs, and only 1 paper contained all of the proposed criteria for establishment of DRLs in the US. The average percentage of criteria included in each of the 7 studies across the 3 sets of guidelines was 63% (range 29-84%) (Table 2).
Conclusions: Reporting of relevant pediatric body CT dose parameters for DRLs for the US is both uncommon and inconsistent, making establishment of DRLs difficult. Future publications and presentations which discuss pediatric body CT dose and DRL implications should adhere to recommended guidelines. These guidelines could serve as initial dialogue for salient organizations (e.g., AAPM, ACR, SPR) in promoting DRL establishment in the US (i.e., for dose monitoring requirements), and in further work with indication-based DRLs.