Radiation exposure in patients treated with endovascular aneurysm repair: what is the risk of cancer, and can we justify treating younger patients?

Background: Endovascular aneurysm repair (EVAR) is becoming the mainstay treatment of abdominal aortic aneurisms (AAA). The postoperative follow-up regime includes a lifelong series of CT angiograms (CTAs) at different intervals in addition to EVAR, which will confer significant cumulative radiation exposure over time. Purpose: To examine the impact of age and follow-up regime over time on cumulative radiation exposure and attributable cancer risk after EVAR. Material and Methods: We calculated a mean effective dose (ED) for the EVAR procedure, CTA, and plain abdominal X-rays (PAX). Cumulative ED was calculated for standard, complex, and simplified surveillance over 5, 10, and 15 years for different age groups. Results: For EVAR, the mean ED was 34 mSv (range, 12-75 mSv) per procedure. For PAX, the ED was 1.1 mSv (range, 0.3-4.4 mSv), and for CTA it was 8.0 mSv (range, 2-20 mSv). For a 55-year-old man, an attributable cancer risk (ACR) in standard surveillance at 5 and 15 years of follow-up was 0.35% and 0.65%, respectively. The corresponding values were 0.22% and 0.37% for a 75-year-old man. When using a simplified follow-up, the ACRs for a 55-year-old at 5 and 15 years were 0.30% and 0.37%, respectively. These values were 0.18% and 0.21% for a 75-year-old man. A complex follow-up with half-yearly CTA over similar age and time span doubled the ACR. Conclusion: Treating younger patients with EVAR poses a low ACR of 0.65% (15-year standard surveillance) compared to a lifetime cancer risk of 44%. A simplified surveillance should be used if treating younger patients, which will halve the ACR over 15 years.