Cancer Risk Associated With Radiation Doses Used for CT Scans in Pediatric and General Hospitals

Describe radiation doses used in common computed tomography (CT) scans by hospital type and estimate the impact of observed dose differences on associated lifetime cancer risk.

Retrospective cohort study in patients aged <21 years undergoing 192 185 CT scans included in a large CT dose registry. Scans were assigned to CT category based on body region imaged, clinical indication, and radiation doses used (routine head, low-dose head, neck, routine chest, routine abdomen). Median radiation doses were compared among hospital types. Excess cancer risks were estimated using the National Cancer Institute Cancer Risk calculator.

For routine head and abdomen and pelvis CT in children aged 12 to <21 years (45% of all scans), radiation doses were 20% to 30% lower in pediatric hospitals (P < .001). In children aged <12 years, routine head doses were 20% lower in pediatric hospitals; abdomen doses varied by age. Pediatric hospitals used radiation doses 30% to 100% higher in children <12 undergoing chest CT (P < .001). An estimated 5500 excess cancers are associated with radiation from CT performed annually in children. An estimated 1200 cancers are associated with differences in dosing.

Radiation doses used for pediatric CT are associated with the development of an estimated 5500 future cancers annually. Differences in radiation doses are associated with an excess estimated 1200 radiation-associated cancers. Further study is needed to determine why dose variation exists in children and adolescents and if optimal doses are being used for the clinical indication of the examination.