Cardiotoxicity Associated with Radiation for Breast Cancer

Abstract

Women treated with radiotherapy (RT) for breast cancer may receive substantial radiation exposure to the heart, which may leave them at risk for increased risk of serious cardiac injury. Historically, women who received radiation therapy as part of their treatment for breast cancer were more likely to die of non-breast cancer-related causes than women who did not receive RT. More contemporary studies, however, suggest that with modern radiation planning techniques, cardiac dose from breast cancer irradiation is minimized in the average patient. Despite this, women undergoing contemporary RT for breast cancer may be at risk for cardiotoxicity as a result of higher than average cardiac dose due to variations in individual anatomy or comprehensive nodal treatment volumes. Moreover, individual risk factors such as comorbid cardiac illness, age, and administration of systemic therapy impact cardiac risk. Strategies to reduce cardiac dose, including deep inspiration breath hold, prone positioning, partial breast irradiation, and proton therapy should be considered, particularly in women at high risk for cardiotoxicity. Based on available data, most current protocols recommend limiting mean cardiac dose and the dose to 5% and 10% of the cardiac volume.