Radiation Treatment for Breast Cancer

External radiation therapy is often prescribed after breast-conserving therapy or mastectomy (once the area has a chance to heal) to kill any cancer cells that may still be in the breast, chest wall or surrounding lymph nodes.

Research has shown that radiation to the remaining breast or chest wall tissue reduces the chances of recurrence in that area (called "local recurrence") by 50-75% of whatever the initial risk would have been. These same trials also showed a 25-30% reduction of systemic metastases and even longer survival in those patients who received radiation. There are some cases where the lymph nodes in the axilla also receive radiation.

For women undergoing radiation therapy, treatment has been classically given over approximately 4-5 weeks, followed by a "boost" to the specific site of the primary cancer or mastectomy scar for approximately 1-2 more weeks, for a total of 6 weeks of radiation therapy. More recently, based on data from clinical trials we have been using shorter courses of treatment of 3-4 weeks for certain patients treated with breast conserving surgery.