A Randomized Comparison of Radiation Therapy Techniques in the Management of Node Positive Breast Cancer

1. Primary Objective 1.1 To compare the extent of new myocardial perfusion defects following breast cancer radiotherapy using the best standard 3-D radiotherapy technique, partially wide tangent fields, versus the best optimized technique. 2. Secondary Objectives 2.1 To compare changes in ejection fraction and alterations in cardiac wall motion with treatment by technique 2.2 To compare changes in lung perfusion defects and pulmonary function tests (DLCO, FEV1, and FVC) by technique 2.3 To compare rates of pericarditis and pneumonitis by technique Cardiac Endpoints: Myocardial SPECT-CT perfusion defects, ejection fraction, alterations in cardiac wall motion, per SPECT-CT (adenosine stress and rest (if necessary)) scan. Pulmonary Endpoints: Lung SPECT-CT perfusion defects per SPECT-CT scan, and changes in pulmonary function tests: DLCO, FEV1, FVC Clinical Endpoints: pericarditis and pneumonitis.