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Going Through Radiation Therapy



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Breast Cancer 101 (Interactive Multimedia) - Radiation Therapy
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Planning session

Radiation therapy can harm normal tissue, so it needs to be carefully planned and precisely given. This helps ensure the radiation kills as many cancer cells as possible while doing as little damage as possible to other parts of your body.  

Your radiation therapy is planned specifically for you and the shape of your body, so sessions cannot be split between different treatment centers. Your therapy plan is based on:

  • Tumor size, type and location
  • The number of lymph nodes that contain cancer
  • The type of breast surgery (and lymph node surgery) you had
  • The shape of your breast and your body

Your radiation oncologist oversees the radiation planning session. During the planning session, you will lie on a special table while the radiation oncologist decides the proper dose of radiation and the best areas to receive the radiation. He/she will use a CT scan to guide the radiation planning.  

During the planning session, the radiation oncologist will put small marks (about the size of a pinhead) on your skin. These marks ensure you are correctly positioned for each treatment. They may be ink spots, or they may be tattoos. If they are ink spots, it is important not to wash them off until after you finish radiation therapy.

Radiation therapy sessions

Your radiation oncologist leads a team that includes technicians and nurses. The team will work with you at each radiation treatment session. During each session, you will lie on a special, firm table. Most often, your entire breast will be given a dose of radiation. If lymph nodes removed during surgery were found to have cancer, the area around the lymph nodes may also be treated with radiation. Learn more about lymph nodes.   

Each session lasts about 20 minutes. Most of this time is spent positioning your body to ensure the treatment is exactly as planned. Treatment usually is given once a day, five days a week, for three to seven weeks. Your schedule of radiation sessions is designed to treat your breast cancer and may vary from another person’s schedule.  

Accelerated, hypofractionated whole-breast irradiation

Some older women with small tumors may get a shortened course (only three weeks) of radiation therapy. This is called accelerated, hypofractionated whole-breast irradiation and is like standard radiation therapy except that it uses a slightly higher dose of radiation per session (hypofractionation). This reduces the number of treatment sessions (making this an accelerated therapy).

Radiation boost

After your radiation therapy sessions end, you may have more radiation (called a boost) to the part of the breast that had the original tumor. This boost radiation is given to get rid of any cancer left in that area. Your boost radiation session is similar to a regular session.


Things to remember while going through radiation therapy 

  • Do not wash the ink marks off your skin.
  • Check with your radiation team before putting any lotions or powders on the affected area.
  • Wear clothing that is easy to take off in case you need to change into a hospital gown.
  • Use reliable birth control to prevent pregnancy (radiation can harm a fetus).
  • Keep the treated area out of the sun.
  • Tell your health care provider about any side effects.

Adapted from the National Cancer Institute materials [13].



For more information on radiation therapy, visit the National Comprehensive Cancer Network (NCCN) or the American Society for Clinical Oncology (ASCO).

Transportation and lodging assistance

If you do not live near the radiation treatment center, it can be hard to get to and from therapy sessions. Sometimes, there are programs that offer help with local or long-distance transportation and lodging. Learn more about these programs.

Updated 03/28/14

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