Radiation therapy uses high-energy x-rays to kill cancer cells or to shrink the size of a tumor in the breast or surrounding tissue. It is used for several weeks following lumpectomy or partial mastectomy, and sometimes after full mastectomy. Radiation therapy can help reduce the chance of breast cancer recurrence in the breast and chest wall. Radiation is also important in advanced stages of cancer for relief of symptoms and to slow progression. Research shows that radiation therapy is helpful for women of all ages, including those over age 65.
Administration of Radiation Therapy
Radiation is generally administered in the following ways:
External Beam Radiation. This type of radiation is administered 4 - 6 weeks after surgery and delivered externally by an x-ray machine that targets radiation to the whole breast. It may be delivered to the chest wall in high-risk patients (large tumors, close surgical margins, or lymph node involvement). The treatment is generally given daily (except for weekends) for about 6 weeks. Some hospitals offer a shortened course of 3 weeks of radiation for patients with early-stage breast cancer.
Brachytherapy. Less commonly, radiation is delivered in implants (called brachytherapy). Implants are most often used as a radiation boost after whole breast radiation.
Side Effects of Radiation Therapy
Side effects of radiation include:
- Fatigue is very common and increases with subsequent treatments, but most women are able to continue with normal activities. Exercise may be helpful.
- Nausea and lack of appetite may develop and worsen as treatment progresses.
- Skin changes and burns can occur on the breast skin. Using a cream that contains a corticosteroid, such as mometasone furoate (MMF), may be helpful. After repeated sessions, the skin may become moist and "weepy." Exposing the treated skin to air as much as possible helps healing. Washing the affected skin with soap and water is not harmful.
- Uncommonly, the breast may change color, size, or become permanently firm.
- Rarely, the nearest arm may swell and develop impaired mobility or even paralysis.
Future complications include:
- Radiation to the left breast may increase the long-term risk for developing heart disease and heart attacks.
- There is a very small risk (less than 1%) of lung irritation and scarring.
- Some studies have reported a higher risk for future cancer in the opposite breast in younger women who have been given radiation to the chest wall.
- Radiation therapy can increase the risk of developing other cancers, such as soft tissue malignancies known as sarcomas.
Current advanced imaging techniques use precise radiation that reduces exposure. These newer techniques are likely to reduce the risks for heart disease and other serious complications.