1. Breast surgery: patients must have undergone either breast-conserving surgery or mastectomy/nipple- or skin-sparing mastectomy. The margins of the resected specimen should be free of invasive tumor and ductal carcinoma in situ (no ink on tumor). In the case of breast-conserving surgery patients with margins positive for lobular carcinoma in situ (LCIS) are eligible without additional resection. For patients who undergo mastectomy, patients with a microscopic positive deep margin are eligible, provided they have received radiotherapy on chest wall.