Central Illustration.

Factors Predicting Radiation-Associated Adverse Cardiac Events

In a median follow-up of 73.7 months, radiotherapy (RT)–associated grade ≥3 adverse cardiac events occurred in 22.3% of those receiving thoracic RT in a median time of 21.5 months. A 5-year cardiac event incidence of 26.7% vs 10.6% (P = 0.004) was seen for high- vs low-dose groups, where left-sided coronary artery volume receiving 15 Gy (V15) exceeding 2.53 cc was considered high. Additionally, high coronary artery calcium (CAC) (score >5) exhibited 28.4% vs 10.7% cardiac events compared with a low score. An integrated model incorporating dose and CAC showed a higher 5-year adverse cardiac event incidences of 6.9% and 28.9% for low-risk vs high-risk patients, respectively. NSCLC = non–small cell lung cancer; OS = overall survival.