Lumpectomy Followed By Intraoperative Electron Radiation Therapy (IOERT)

Inclusion Criteria:

• Patient agrees to breast conservation therapy (segmental resection, partial mastectomy, and radiation therapy) as the treatment for their breast cancer
• Patient agrees to evaluation of the axilla with sentinel lymph node biopsy
• Peri or post-menopausal women age > 50, defined as women who have experienced no menstrual period in the past 6 months or more
• BRCA1 and 2 gene mutation negative, if tested. [genetic testing is NOT required based upon personal or family history]
• Unifocal (unicentric), invasive ductal carcinoma or favorable sub-types (mucinous, tubular, colloid) < 2.0 cm in diameter, primary T-stage of Tis or T1 (AJCC criteria)
• Grade 1, 2, or 3 acceptable
• Associated LCIS is allowed
• Pure DCIS allowed if <2.5 cm, low to intermediate nuclear grade and resected margins negative at > 3 mm (per ASTRO criteria)
• Estrogen receptor (ER) status of positive
• Patient has clear margins >2 mm on gross pathologic examination
• Patient is node-negative, defined as N0 (i-) or N0 (i+)
• Patient must be deemed functionally and mentally competent to understand and sign the informed consent
• Neoadjuvant hormonal therapy is allowed if all other ASTRO suitable criteria have been met prior to onset of hormonal therapy

Exclusion Criteria:

• Prior breast malignancy or other malignancy if metastatic, or with expected survival of < 5 years
• Immunocompromised status
• Pregnancy
• Women with an active connective tissue disorder (i.e. scleroderma, lupus and others)
• Breast cancer that involves the skin or chest wall, locally advanced breast cancer
• Invasive lobular carcinoma
• Evidence of lymphovascular invasion (LVI)
• Invasive carcinoma with extensive intraductal component (EIC)
• Neoadjuvant chemotherapy
• Patients with 1 or more positive lymph node determined during surgery with sentinel node and/or axillary dissection
• Someone who is not a candidate for breast conserving management, i.e., prior whole breast radiation therapy