Proton Therapy for Early Stage Breast Cancer

Radiation therapy is considered standard treatment for most women with early stage breast
cancer following lumpectomy. Post-lumpectomy radiotherapy is a proven treatment that reduces
cancer recurrence in the breast and improves survival. When standard whole breast radiation
techniques are utilized, portions of the chest wall, lung and heart may also receive
significant doses of radiation which can lead to radiation induced complications. Radiation
techniques that limit the treatment area to the portion of the breast where the cancer arose
can minimize and even eliminate radiation dose to the chest wall, heart and lung. This is
called partial breast radiotherapy. This study is designed to evaluate the use of proton beam
radiotherapy to deliver partial breast radiotherapy in women with early stage breast cancer.

Inclusion Criteria:

- Invasive ductal, medullary, papillary, colloid or tubular histologies

- Stages T1 or T2 (tumors < or = 3 cm) from lumpectomy specimen.

- No more then 3 positive nodes on axillary dissection or negative sentinel node.

- Negative surgical margins (>2mm)

Exclusion Criteria:

- Invasive lobular histology

- Previous chemotherapy for breast cancer

- Extensive intraductal component

- Collagen vascular disease

- Prior malignancy unless disease-free for 5 years

- Patients who are pregnant or lactating