For patients with certain types of breast cancer, one standard treatment is breast conserving surgery or lumpectomy (surgery to remove abnormal tissue or cancer from the breast and a small amount of normal tissue around it) followed by breast radiation. The radiation treatment in this situation usually lasts 3 to 5 1/2 weeks followed by 5-8 daily localized irradiation (or boost) treatments at the site where the lump was removed. During this study, the single dose of electron irradiation given at the surgical site during the operation will replace the radiation given after surgery.
