What is Radiation Therapy?

Radiation therapy uses high-energy beams to destroy cancer cells. The beams resemble the X-rays that are used to create an image of the chest, or of a broken bone. For treatment purposes, the rays are of higher intensity. High doses of radiation can destroy the ability of cells to grow and multiply.

Radiation therapy is given after a lumpectomy to destroy any cancer cells that might remain in the breast area, and to prevent recurrence. Unlike chemotherapy—a systemic treatment that treats the entire body—radiation therapy is considered a local treatment, because it treats only the breast area.


Barbara Schlager, MD – “Why you need radiation therapy.”

There are two ways to administer radiation therapy: External beam radiation therapy, which is delivered by a machine from outside the body in short daily treatments over five to seven weeks; brachytherapy, delivered by small devices placed inside the breast for a few days only; and intraoperative radiation therapy, or IORT, using a single large dose at the time of surgery.