BMI-Adjusted Tube Current in Chest CT and Comparison of Lifetime Attributable Risk (LAR) of Breast Cancer in Two Different BMI-Based Protocols

Possible strategies to reduce radiation dose during CT scanning have been investigated over recent decades; here the optimization of the tube current and its link with patient’s cancer incidence are being evaluated. 154 consecutive trauma patients with the need for chest CT scan were included. Two different BMI-adjusted CT protocols at a fixed voltage tube and the same scan length were applied. Dose estimation parameters like CT dose index (CTDI), dose length product (DLP) and effective breast dose were calculated. Breast surface dose was obtained by using thermoluminescence dosimeters (TLDs) and eventually, the life attributable risk (LAR) of cancer incidence was estimated. The mean effective dose was 4.87 ± 2.3 mSv and 5.12 ± 2.8 mSv for patients who were scanned with tube currents of 120 mAs and 200 mAs, respectively. There was no significant difference between organ surface doses for females but in males it was notable. The risk of cancer incidence is lower for protocol 1 in comparison with protocol 2. Optimizing tube current of 120 mAs reduced breast surface dose up to 50% in comparison with the tube current of 200 mAs. In trauma patients, using lower tube current based on BMI has notable impact on the absorbed dose in the breast and can reduce the breast cancer risk by nearly 33.6% for women.