Emerging Technologies in Mitigating the Risks of Cardiac Toxicity From Breast Radiotherapy

Technical advances in radiation oncology may allow for greater reduction in the late toxicities associated with breast radiotherapy. In this review, we explore emerging technologies that show specific promise for the identification and reduction of radiation-induced cardiac toxicity namely, proton therapy and cardiac autosegmentation. First, we will examine the historical risks of cardiovascular morbidity and mortality in breast cancer, including trends in cardiac radiation exposure over time. Then, we will highlight the rationale for proton therapy, including the early dosimetric and clinical studies available to-date, to underscore proton therapy's unique potential for limiting cardiac radiation exposure and preserving cardiac function among patients with breast cancer, with consideration of modern cardiac dose constraints. Finally, we will focus on the development of cardiac contouring atlases and substructure auto-segmentation methods in order to demonstrate opportunities for integration of auto-segmentation into dosimetric planning and outcome prediction.