Since 1990, breast cancer mortality has decreased yearly in developed nations. In 2012, there were an estimated 3 million survivors of breast cancer in the United States alone.¹ This decrease in mortality can be partly attributed to effective treatment strategies developed through collaborations among breast surgeons and medical and radiation oncologists. Radiation therapy has evolved as a critical component of treatment for women who have undergone breast-conservation surgery and for those with a high risk of recurrence who have undergone mastectomy.² Older radiation techniques for breast cancer are associated with subsequent cardiac disease. Less clear is the cardiac risk associated . . .