Estimates of lifetime attributable risk of cancer after a single radiation exposure from 64-slice computed tomographic coronary angiography

Aims To estimate the life attributable risk (LAR) of cancer incidence over a wide range of dose radiation exposure and a large spectrum of possible diagnostic computed tomographic coronary angiography (CTCA) scenarios. Methods This study included 561 consecutive patients who underwent a successful prospective ECG-gating CTCA protocol (low-dose group) 64-slice CTCA and 188 patients who underwent retrospective ECG-gating CTCA with ECG-triggered dose modulation CTCA (high-dose group). LAR was computed, given the organ equivalent dose, for all cancers in both sexes. LAR was tabulated for each decile of dose-length product by 10-year age classes, separately for each sex. Results Estimates of LAR of any cancer for an exposure at age <= 40 year were lower in males than in females for any given quantile. At age >= 50 years, LAR was similar between sexes only at the lowest exposure doses, whereas at higher dosage, it was, in general, higher for women. At the median age of this case series (62 years) and for a radiation exposure ranging from 1.33 to 3.81 mSv, LAR was 1 in 4329 (or 23.1 per 10(5) persons exposed) and 1 in 4629 (or 21.6 per 10(5) persons) in men and women, respectively. For an exposure ranging from 10.34 to 18.97 mSv at the same median age, the LAR of cancer incidence was 1 in 1336 (or 74.8 per 10(5) persons) in men and doubled (1 in 614 or 162.8 per 10(5) persons) in women. Conclusions This study provided an estimate of the LAR of cancer in middle-aged patients of both sexes after a single diagnostic CTCA, providing an easy-to-read table.