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Radiation Therapy for Breast Cancer

Radiation therapy typically involves using a large machine called a linear accelerator to deliver precise amounts of high-energy radiation to kill cancer cells. The radiation stops the reproduction of cancer cells while minimizing damage to healthy tissues. Radiation therapy has been shown to improve survival in women with breast cancer.

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Radiation therapy for breast cancer can be used:

  • After lumpectomy or mastectomy, either alone or in combination with chemotherapy and/or hormone therapy, to reduce the risk of cancer re-growing in the breast.
  • As the main treatment for breast cancer if the surgeon believes the tumor cannot be safely removed, if a woman's health does not allow surgery, or if the woman chooses not to have surgery.
  • To treat cancer that has spread into the bones or the brain.
  • To relieve pain or other problems if the cancer recurs.

Radiation Therapy Side Effects

Radiation therapy is painless. However, some women experience side effects, which can include:

  • Redness, discomfort, and dryness of the skin in the treated area. Your doctor will recommend a specific treatment if this happens. The redness can take as long as a year to fade.
  • Fatigue, usually starting two to three weeks after treatment begins. The fatigue increases during the duration of treatment and goes away about a month after treatment ends. Fatigue should not disable you. Most women cope by taking a nap or by going to bed earlier.
  • Reduced blood counts. Your blood will be checked regularly, especially if you are also receiving chemotherapy.

Sometimes women also experience a sore mouth or throat, or dry mouth, if these areas are irradiated.

For more information about possible side effects, see Side Effects of Cancer Drugs and Radiation.

During radiation therapy for breast cancer, women should:

  • Contact the doctor if they develop unusual symptoms, such as coughing, sweating, fever, or unusual pain.
  • Get enough rest and eat a healthy diet.
  • Go for regular blood tests as required by the doctor.
  • Be extra kind to the involved area. Avoid tight clothes or anything that rubs.
  • Protect the area from exposure to the sun.
  • Apply moisturizing creams after radiation is complete.

Many advances in radiation therapy for breast cancer have helped women avoid long-term side effects. However, they can happen and include:

  • Rib fractures, which tend to heal without treatment (less than 1%)
  • Lung inflammation, which tends to resolve on its own (less than 1%)
  • Damage to the heart (Older methods of radiation therapy caused more problems. New advances avoid direct radiation to the heart.)
  • Scarring
  • Very rarely, radiation therapy may be associated with causing other tumors such as sarcoma


WebMD Medical Reference

Reviewed by Laura J. Martin, MD on February 10, 2012

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