Left anterior descending (LAD) coronary artery V15 has emerged as a risk factor for adverse cardiac events after radiation for NSCLC. This study sought to validate the significance of LAD V15 using data from RTOG 0617, which compared standard and dose-escalated definitive radiation for NSCLC. Median LAD V15 was 38%. V15 <10% has been identified as a good threshold for increased risk of cardiac events. In 0617, a minority of patients (21%) had a V15 <10%. The study confirmed that V15 >10% was associated with an increased risk of mortality, and median OS was 20.2 months compared to 25.1 months for those with a V15 <10%. In addition, the study also confirmed that mean heart dose was not as strongly associated with mortality as LAD V15.
- McKenzie, Int J Radiat Oncol Biol Phys 2022