Radiation Therapy to the Breast

You are scheduled to receive radiation therapy designed specifically for you. The following guidelines will help you take an active part in your radiation treatment. 

What to Expect During Your Treatment

Temporary Skin Changes

Temporary skin changes may occur. Usually these include redness, dryness, scaling, and itching of the treated area. Skin changes usually occur one to two weeks after your treatment begins and may last one to two weeks after your last treatment.  Darkening of the skin in the treated area can occur.

  • Apply moisturizers to the treated area two or three times a day. Do not use moisturizers within two hours before a radiation treatment. Do not use any other products on your skin in the area of treatment.  Suggested moisturizers include:


  • Use  a gentle soap on your skin. Pat the skin dry with a towel; do not rub. You may use a hair dryer on the cool setting to help dry the skin around the breast, especially the area under the breast under the affected arm. Suggested mild soaps include:________________________________
  • Do not shave your underarm.
  • Applying deodorant may irritate the treated underarm. Suggested underarm products include


  • Do not use a heating pad or hot water bottle on the area being treated with radiation therapy
  • Do not use a hot tub or sauna while undergoing treatment
  • Surgical bras and sports bras are acceptable. No underwires.
  • Wear light, loose-fitting clothing made of 100 percent cotton or cotton blend.

Breast Changes

Fullness and mild swelling of the breast may occur during treatment. These changes will decrease slowly over time.

You may experience occasional warm sensations, tingling, or shooting pains in your breast. These sensations decrease slowly over time. If you have discomfort, you may take pain medication as needed:


Long-term effects may continue for one year or longer after treatment. You may notice that your breast is firmer than it was before treatment. Sometimes the size of your breast changes. It may become larger or smaller. The skin and fatty tissue of the breast may feel thicker.

Permanent Skin Changes

Permanent skin changes include increased sensitivity to hot and cold temperatures and some-times a darker coloration (hyperpigmentation).

If the area being treated is exposed to the sun, apply sunscreen routinely to the treatment site whenever you are outdoors for more than 10 minutes during summer or winter. Use PABA-free sunscreen with a sun protection factor (SPF) of at least 30. Since the area being treated will always be more sensitive than the rest of your skin, protect the area from sun exposure after your treatment ends.

Sexual Concerns

Birth control is strongly recommended during treatment, since radiation therapy may pose risks to an unborn child. 

What to Ask Your Nurse or Doctor

Ask your nurse or doctor any questions you may have about the following:

  • Skin care and moisturizers
  • Birth control methods
  • Sexuality issues
  • Concerns about changes in the way your breasts look and feel
  • Availability of support groups

Things to Report to Your Nurse or Doctor

Tell your nurse or doctor if you have any of the following symptoms:

  • Red and/or tender skin
  • Painful, blistering, moist, or weepy skin
  • Nipple tenderness
  • Dry and/or itchy skin
  • Discomfort in the treated area
  • Swelling of the breast, underarm, or arm
  • Any new or unusual symptoms

Things to Report Immediately

  • Temperature of 100.5°F (38°C) or above
  • Chills

In an Emergency Call: