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Radiation Therapy for Breast Cancer

Radiation therapy, also called radiotherapy, focuses high-energy x-rays on the breast cancer tumor. The radiation damages the DNA and other structural aspects of the cancer cells. This either destroys the cells or weakens them enough to make it hard for them to reproduce.

What’s Radiation, Anyway?

Radiation is energy in the form of heat or light that travels through space. Sunlight is one of many forms of radiation. X-rays that your doctor or dentist uses during routine medical exams is another.

There are two types of radiation therapy that may be used in breast cancer treatment. Some people may receive both kinds:

  • External radiation therapy is similar to having an X-ray taken. A machine outside the body is used to direct radiation beams at the tumor.
  • Internal or implant radiation is a procedure that places radioactive material directly in the breast near or within the tumor.

Internal radiation therapy is frequently used after a lumpectomy, since studies suggest that without radiation treatment, the cancer is very likely to recur in the same site. Because internal radiation therapy precisely targets a localized area — such as the cavity where a tumor was removed — it can significantly reduce the chances of a cancer recurrence.

Energizing the Fight Against Cancer

Learn the basics of radiation therapy in Your Guide to Cancer Care.

The way radiation may be used in your cancer treatment depends on your particular diagnosis. Radiation therapy is customary after surgery. However, you may also receive radiation therapy in combination with hormone therapy or chemotherapy to shrink the tumor before surgery.

Learn about external radiation:

External beam radiation

External beam radiation therapy Before external radiation begins, your radiation oncologist and a medical physicist plan your breast cancer treatment by measuring the correct angles to aim the radiation beams to target a specific area of your body.

Getting external beam radiation, or EBRT, is similar to getting an X-ray, though it lasts a few minutes instead of just a few seconds. Most people receiving external radiation go to the hospital or clinic as out-patients each day while they’re in treatment. For instance, when EBRT follows breast-sparing surgery, you usually have treatments five days a week for five to seven weeks. At the end of treatment, you may receive an extra “boost” of radiation to the place where the tumor was removed.

While you receive EBRT, the radiation therapist leaves the room and monitors you on a close-circuit television. You are able to communicate with him or her at any time over an intercom system.

3-D conformal radiation

Learn More

Learn about the whole spectrum of radiation therapies.

One high technology approach to external radiation that may be used to treat breast cancer is 3-D conformal radiation. Using computer simulation techniques, an accurate three-dimensional image of the tumor and surrounding organs is created. This allows the radiation oncologist to deliver multiple radiation beams precisely shaped to the contour of the tumor and treatment area. Because radiation beams are so accurately focused, nearby normal tissue is spared.

Intensity modulated radiation therapy

3-D Animation

Watch a medical animation to see how intensity modulated radiation therapy, or IMRT, works.

Intensity modulated radiation therapy, or IMRT, allows oncologists to direct multiple, thin beams of radiation at a breast cancer tumor and accurately control the intensity of the radiation.

IMRT allows each dose of radiation to be custom-tailored to the exact size, shape, and location of the tumor. That makes it easier for your oncologist to spare healthy tissue surrounding the cancer.

IMRT may be an option if you’ve previously been treated with conventional radiation therapy and tumors have recurred in the treated area.


3-D Animation

Watch a medical animation to see how Tomotherapy works.

Tomotherapy is an innovative treatment that combines state-of-the-art Intensity Modulated Radiation Therapy (IMRT) with the precision of computed tomography, or CAT, scanning technology.

CAT scanning uses X-ray technology and digital imaging techniques to create detailed three-dimensional cross-sectional pictures of the interior of the body.

Doctor’s Note

Listen to Dr. Bernard Eden of Cancer Treatment Centers of America discuss the benefits of tomotherapy.

Unlike traditional external radiation therapies that project radiation on a tumor from only a few directions, Tomotherapy targets breast cancer tumors with powerful doses of IMRT radiation therapy from 360 degrees. This allows your radiation oncologist to better plan your breast cancer treatment to avoid damage to muscle tissue, the spine, lungs, and other sensitive organs. For instance, if your tumor has shifted or changed shape since your last breast cancer treatment, your medical team can adjust for that.

Retreatment with Tomotherapy

Another benefit of Tomotherapy is that it may allow people with recurrent advanced breast cancer to receive retreatment to previously radiated tumors.

Learn More

Find out more about how tomotherapy delivers radiation with unprecedented precision in Your Guide to Cancer Care.

When cancer recurs in a part of the body that has been radiated in the past, retreatment can lead to scarring and ulceration. However, because of tomotherapy’s precision, retreatment may be safer and more effective for people who have reached their maximum tolerance for conventional radiation treatment. Your oncologist can help you determine whether Tomotherapy is an option for you based on your diagnosis, symptoms, and the size of the tumor.

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