Radiation Therapy During Surgery in Treating Older Women With Invasive Breast Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed primary invasive ductal carcinoma of the breast * Tumor size ≤ 3 cm * No extensive intraductal component * Tumor must not be attached to the skin, underlying muscle, or chest wall * Candidate for breast-conserving therapy, as determined by the surgical and radiation oncologist * Tumor amenable to segmental mastectomy (i.e., lumpectomy) * No bilateral breast cancer * No clinical or radiographic multifocal disease not amenable to single segmental mastectomy * Patients with \> 1 tumor mass in the same breast must have only 1 mass that is histologically malignant AND all other masses must be proven histologically benign * Hormone receptor status: * Not specified PATIENT CHARACTERISTICS: Age * 48 and over Sex * Female Menopausal status * Not specified Performance status * 0-2 Life expectancy * At least 5 years Hematopoietic * Not specified Hepatic * Not specified Renal * Not specified Other * Not pregnant * Fertile patients must use effective contraception * No collagen vascular disease * No medical condition that would preclude surgery * Other prior malignancy allowed provided the following criteria are met: * Patient has undergone potential curative therapy for all prior malignancies * There is no evidence of any prior malignancy within the past 5 years * Patient is deemed to be at low risk for recurrence of prior malignancy, as determined by the treating physician PRIOR CONCURRENT TH…