Intensity Modulated Radiation Therapy or 3-Dimensional Conformal Radiation Therapy in Treating Patients With Lymph-Node Positive Breast Cancer

PRIMARY OBJECTIVES: I. To determine if intensity modulated radiation therapy (IMRT) reduces average 1-year patient-reported shoulder/arm morbidity in women receiving regional nodal irradiation (RNI) for lymph-node positive breast cancer as compared to historical data. SECONDARY OBJECTIVES: I. To measure patient-reported shoulder/arm morbidity in women receiving RNI with 3-dimensional conformal radiation therapy (3DCRT) for lymph-node positive breast cancer. II. To measure change in shoulder range of motion in women receiving RNI. III. To measures rates of ipsilateral upper extremity lymphedema in women receiving RNI. IV. To explore the dose volume parameters to the shoulder/neck/trunk musculature associated with worsening patient-reported shoulder/arm morbidity. V. To assess disease outcomes in patients treated with IMRT. VI. To measure long-term patient-reported shoulder/arm morbidity in women receiving RNI with IMRT or 3DCRT. OUTLINE: Patients are assigned to 1 of 2 arms. ARM A: Patients undergo IMRT over 5 weeks. ARM B: Patients undergo 3DCRT over 5 weeks. After completion study treatment, patients are followed up at 1, 6, and 12 months, and then annually for up to 5 years.