Lifetime attributable risk of cancer from CT among patients surviving severe traumatic brain injury.

Abstract

The purpose of this study was to determine the lifetime attributable risk of cancer from CT among patients surviving severe traumatic brain injury. 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. 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%. 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.