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.
