External beam radiation therapy for breast cancer

External beam radiation therapy is a local treatment, which means it treats a specific part of your body. It may be given to the whole breast or chest, or to the part of the breast where the cancer is or where it was located before it was removed by surgery. Most of the time, you will get external beam radiation therapy as an outpatient.

To learn how to prepare for radiation therapy, visit the booklet Radiation Therapy and You: Support for People with Cancer.

Radiation therapy for breast cancer usually begins about a month or two after surgery. That is because radiation therapy can slow wound healing. If you are also receiving chemotherapy, radiation therapy usually starts about a month after you have finished chemotherapy. You can have radiation at the same time as you are receiving some other treatments, such as hormone therapy or targeted therapy.