Objective: The purpose of this study was to determine the lifetime attributable risk of cancer from CT among patients surviving severe traumatic brain injury.
Materials and methods: A retrospective cross-sectional study was conducted with prospectively collected data on patients 16 years old and older admitted with a Glasgow coma scale score of 8 or less to a single level 1 trauma center from 2007 to 2010. The effective dose of each CT examination the patients underwent was predicted with literature-accepted effective dose values of standard helical CT protocols. The lifetime attributable risk of cancer and related mortality incurred as a result of CT were estimated with the cumulative effective dose incurred from the time of injury to a 1-year follow-up evaluation and with the approach established by the Biologic Effects of Ionizing Radiation VII report.
Results: The average patient was a 34-year-old man. The median number of CT examinations received during the first 12 months after injury was 20, and the average cumulative effective dose was 87 ± 45 mSv. This resulted in increases in the lifetime incidence of all cancer types from 45.5% to 46.3% and in the lifetime incidence of cancer-related mortality from 22.1% to 22.5%.
Conclusion: Radiation exposure from the use of CT in the evaluation and management of severe traumatic brain injury causes negligible increases in lifetime attributable risk of cancer and cancer-related mortality. Treating physicians should not allow the concern for future risk of radiation-induced cancer to influence decisions regarding radiographic evaluation in the acute treatment of traumatic brain injury.