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

Radiotherapy has been shown to reduce breast-cancer specific mortality in patients at high risk for distant dissemination. It has also been shown to increase rates of non-breast cancer deaths and morbidity due to cardiovascular and pulmonary toxicity. Although treatment planning has improved significantly through the years, recent reports still demonstrate treatment-related morbidity even with 3-dimensional planned techniques. Thus, while 3D planning represents the state of the art treatment for loco-regional radiotherapy for breast cancer, further improvement is needed to continue to decrease heart and lung exposure. The ultimate goal of the proposed research is to determine whether treatment planning using intensity-modulated radiotherapy (IMRT), the "next generation" of radiation treatment delivery systems, results in less radiation exposure to the heart and lungs than the best current RT technique in women with node positive breast cancer. This proposal will test the potential clinical value of IMRT compared to the best standard 3D plan (partially wide tangent fields, PWTF) in the treatment of breast cancer. These two treatment techniques will be studied in a Phase II randomized trial using quantitative indicators of potential cardiac and lung toxicity. The preliminary data generated from this trial will be used to ultimately justify a multi-institutional comparison of the two treatment techniques with long-term clinical cardiac and pulmonary toxicity as endpoints.

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.