Cumulative dose in pediatric CT "frequent flyers": cohort results and risk review

Published surveys have documented increasing cumulative radiation doses from the increased use of CT over recent decades, but pediatric data on this are sparse.

To determine what percentage of pediatric patients receive a high cumulative effective dose (CED) from repeated CT scans in our practice, and to examine the reasons for this.

Our dose monitoring software maintains a record of CED in all patients undergoing CT. Those who received a CED ≥50 mSv and ≥100 mSv were tabulated for further analysis. The highest dose outliers were flagged for analysis of clinical rationales of CT use, calculation of cumulative absorbed dose profiles, and outcomes.

From 2013-2023, we performed CT in 10,199 patients aged 0-19 years, of whom 75% had one, 14% had two, 5% had three, 3% had four, and 3% had five or more CTs. Of our cohort, 97 (0.95%) reached the CED dose threshold of 50 mSv at age 16.0±3.0 (16.9) years [mean±SD (median)], and 20 (0.20%) also reached the 100 mSv threshold at age 16.2±1.8 (16.5) years. The highest CED values occurred in patients with serious and catastrophic conditions, in overweight adolescents, and because of repeated high-dose multiphasic acquisitions and CT-guided interventions.

Most of our patients (89%) had only 1-2 CT scans. Although only 0.95% and 0.20% of our pediatric patients experienced CEDs more than 50 mSv and 100 mSv (respectively) from repeated CT scans, these groups deserve close attention, as they often continue to accumulate doses throughout childhood and beyond.