Purpose

To determine whether an accelerated course of radiotherapy delivered to the lumpectomy cavity plus margin using IORT as a single dose, intracavitary brachytherapy with the MammoSite device over 5 days, partial breast 3-D CRT in 5 days, or stereotactic APBI over 4 days is a feasible and safe alternative to a six and a half week course of whole breast radiotherapy. The study will measure both short and long-term complications of radiation treatment, short and long-term breast cosmesis, local rates of in-breast cancer recurrence, regional recurrences, distant metastases, and overall survival.