Cardiac toxicity is a significant cause of morbidity and mortality in cancer survivors after radiation therapy (RT) to the chest. Typically, cardiotoxicity is identified years after radiation exposure. Emerging clinical data show that subclinical injury can be identified immediately after treatment. Early identification of subclinical injury may enable intervention to reduce the risk of progression to clinically significant toxicity. The investigators hypothesize that cardiac magnetic resonance imaging (CMRI) will detect early cardiac injury after RT and that imaging changes will be associated regionally with cardiac radiation dose.
The investigators will identify 10 patients in the department of radiation oncology who will receive standard of-care radiation therapy, and the treating radiation oncologist anticipates a mean left ventricular dose of at least 5 Gy. Patients will be evaluated by CMRI before and within one week of the completion of RT. We will compare the pre- and post-RT CMRI scans to identify changes related to radiation exposure. Our primary endpoint will be changes in myocardial strain. Secondary endpoints will include other CMRI parameters.