Study of Cardiac MRI in Patients With Left-Sided Breast Cancer Receiving Radiation Therapy

As part of this study, participants will have a cardiac MRI at baseline and a follow-up cardiac MRI within 1 year after completion of standard radiation therapy for left-sided breast cancer. The cardiac MRI scans will be evaluated to determine if there are changes in cardiac function within 1 year after radiation treatment. Patients will be asked to complete a questionnaire before and after treatment that asks about their health and any symptoms they may be having. Physical exams and any other standard of care service or treatment will be at the discretion of the treating physician.