Following consent, patients will receive 15 fractions of radiotherapy to the affected breast and to Axillary level III and SCV (Supra-Clavicular) lymph nodes, defined by CT imaging obtained in a prone position using IMRT(intensity modulation radiation therapy ) technique: one fraction daily for 5 days/week for 3 consecutive weeks. Patients will be seen for follow-up at 45-60 days from first radiotherapy treatment, and then yearly. Patients will be assessed for Lymphedema at baseline, end of treatment, and at yearly intervals after completion of radiotherapy. All patients will be followed for toxicity and outcome (local and systemic recurrence, survival). In addition, patients will complete a self-assessment of QOL at baseline, week 3, day 45-60 and 2-yr follow-ups.

A recent Cochrane Collaboration Intervention Review has addressed the effects of altered fractionation size on women with early breast cancer who have undergone breast conservation surgery. Analysis of two prospective randomized trials that included 2644 women, selected based on tumor size less than five cm, negative pathological margin of excision and negative lymph nodes. No difference in clinical outcome was detected. The conclusion of the review is that the use of unconventional fractionation regimens (greater than 2 Gy per fraction) does not affect breast appearance or toxicity, and does not seem to affect local recurrence or five years survival rates.

After breast surgery and an adequate axillary dissection (i.e., at least 8 nodes retrieved in the axillary dissection specimen from level I and II) it is possible to identify patients with 1 - 5 positive nodes who require radiotherapy to both the indexed breast/chest wall and the draining nodal stations that the surgeon did not include in the traditional level I - II axillary dissection, i.e., level III and supraclavicular stations. We are proposing to test a new technique that extends prone set up to also include these lymph node regions. Limiting treatment to the supraclavicular fossa and level III axilla in patients with an adequately dissected axilla is supported by several published studies. Regional nodal recurrences are rare (occurring in 1 - 5%) in patients with early stage invasive breast cancer who have undergone breast conserving therapy. Several institutions choose to treat only the level III axilla and supraclavicular nodal stations in patients who have undergone surgical treatment of level I/II axilla. This technique was documented recently by Liengsawangwong, who utilized CT-delineated nodal stations to improve target coverage of SCV (Supra-Clavicular) and level III axillary nodes in patients who had undergone axillary level I/II dissection and were found to have positive lymph nodes.

Inclusion Criteria:

• Pre- or post-menopausal women with stage II - III breast cancer (AJCC 2002)
• Biopsy-proven invasive breast cancer, excised with negative margins of at least 1 mm
• Status post segmental mastectomy or mastectomy and axillary node dissection with removal of at least 8 nodes
• One to 5 involved lymph nodes identified at axillary staging
• At least 2 weeks from last chemotherapy or before chemotherapy
• No more than sixty days from final surgery to simulation if no systemic therapy (includes chemotherapy and Hormonal therapy) is given
• Patient needs to be able to understand and demonstrate willingness to sign a written informed consent document

Exclusion Criteria:

• Previous radiation therapy to the ipsilateral breast
• More than 5 involved nodes identified at axillary staging
• Current treatment for active connective tissue disorders, such as lupus or scleroderma
• Pregnant or lactating women
• Less than 35 years old

5 years from the first day of treatment

Adverse Events are collected throughout the study period via physical exams, lab assessments as well as patient communications.