Jimenez RB, Hickey S, DePauw N, et al. - For patients with breast cancer who require regional nodal irradiation, researchers tested the effectiveness and safety of proton beam radiation therapy (RT). Patients with nonmetastatic breast cancer who required postoperative RT to breast/chest wall and regional lymphatics and were considered to be suboptimal candidates for conventional RT were eligible. Between 2011 and 2016, 70 patients completed RT. According to findings, breast cancer proton beam RT demonstrated low toxicity rates and comparable disease control rates vs conventional RT historical data. No significant changes were found after RT in echocardiography or cardiac biomarkers. No early cardiac changes were noted, paving the way for the comparison of proton beam RT with standard RT for randomized studies.