This is a pilot study to determine if there are changes in heart function following completion of radiation therapy for breast cancer as measured by cardiac magnetic resonance imaging (cardiac MRI) scans. Additional purposes of this study are to assess cardiac side effects from radiation treatment, evaluate cardiac MRI changes by radiation technique, and compare quality of life questionnaires.

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.

Inclusion Criteria:

• Left-sided breast cancer stage I-III.
• Indications for adjuvant regional nodal and breast or chest wall radiation therapy (RT).
• Women and men are allowed.
• Must be at least 18 years old at time of consent.

Exclusion Criteria:

• Pregnant and/or breastfeeding women or patients of child-producing potential not willing to use contraception while on study.
• Prior history of cardiovascular disease per physician discretion.
• Stage 0 and IV breast cancer.
• Prior radiation therapy to chest.
• Concurrent trastuzumab per physician discretion.

Radiation oncology clinic