Theoretical breast cancer induction risk from thoracic spine CT in female pediatric trauma patients.

OBJECTIVES To quantify the radiation dose received during thoracic spine computed tomography (CT) versus plain radiographs as well as the theoretical risk of breast cancer induction in a pediatric trauma population. METHODS A retrospective evaluation of 179 female pediatric trauma patients who received CT or plain radiographs for clearance of the thoracic spine was performed. Subjects were secondarily grouped as children (0-<12 years) or adolescents (≥12-17.9 years). Radiation doses were calculated by using the ImPACT Patient Dosimetry Calculator. Excess absolute risk (EAR) of induction of breast cancer was determined by multiplying the radiation dose by breast cancer induction rates taken from the National Academy's Biological Effects of Ionizing Radiation Committee's seventh report. RESULTS The average radiation dose to the breast from a thoracic spine CT was 41.1 (SD 11.4) mSv and 1.8 (SD 0.9) mSv for plain radiographs. The EAR for plain radiographs was 2.7 (95% confidence interval [CI] 2.48-2.85) excess cases of breast cancer per 10 000 studies for female children and 1.4 (95% CI 1.14-1.55) for female adolescents. The breast cancer EAR for thoracic spine CT was significantly higher -79.6 (95% CI 58.6-100.5) and 45.8 (95% CI 42.0-49.6) excess cases per 10 000 scans for female children and adolescents, respectively. There was a substantially higher risk of breast cancer induction for children receiving thoracic spine CT compared with adolescents. CONCLUSIONS CT clearance of the thoracic spine in the pediatric trauma patient results in a high dose of radiation and an age-dependent increase in theoretical breast cancer induction.