Investigators hypothesize that CMR and biomarker examinations before and after radiotherapy for lung and breast cancers will demonstrate evidence of cardiac strain and dysfunction proportional to the extent of cardiac exposure during the course of radiation. Investigators intention is to conduct a pilot study of 10 patients receiving moderate doses of radiation exposure to the heart (5 lung cancer patients and 5 breast cancer patients) when treated by our current institutional standards with the idea that this could lead to a grant if early signs of cardiac injury can be measured. These patients' treatment plans would include contours to measure dose received by multiple structures within the heart (coronary vessels and all cardiac chambers) as well as the heart/pericardium itself. Investigators would obtain biomarkers by bloodwork before, during, and after radiotherapy for correlation with clinical outcomes and Cardiac MRs obtained prior to and 1 year after completion of radiotherapy.