By next year, we expect 06/17 to be national lung and heart dosimetry awareness month. Two recent studies used artificial intelligence to identify conventional predictors of toxicity as well as novel cardiopulmonary substructures using treatment plans from RTOG 0617, which compared standard and dose-escalated chemoradiation for locally advanced NSCLC. The first study looked at the typical predictors of toxicity such as mean dose and V20. AI identified Dmean >18 Gy and V20 >37% as thresholds for pulmonary toxicity, and Dmean >34 Gy and V20 >37% for esophageal toxicity. Interestingly, there was no significant threshold for heart Dmean or V40 cardiac toxicity. The second study delineated cardiopulmonary substructures such as the atria, ventricles, pericardium, and great vessels. AI identified the most important substructure dose associated with overall survival as the left atrium V60. Substructure dose thresholds associated with improved overall survival were: left atrium V60 <25.6%, volume of lungs overlapping with the CTV/PTV <1.1%, pericardium D30% <18.9 Gy, and right atrium V55 <19.5%. | Lee & Ladbury, Int J Radiat Oncol Biol Phys 2023
