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What you can expect

By Mayo Clinic staff

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The typical schedule for external radiation treatments is therapy five days a week for three to six weeks. The sessions are done on an outpatient basis, often at a hospital or other treatment facility. You may be able to schedule your sessions at the same time each day so they can become a part of your routine.

The duration of internal radiation therapy for breast cancer is much shorter, usually five days total. Internal radiation sessions are typically done on an outpatient basis.

External radiation
A typical radiation therapy session generally follows this process:

• When you arrive at the hospital or treatment facility, you're taken to a special room that's used specifically for radiation therapy.
• You may need to remove your clothes and put on a hospital gown for the session.
• The radiation therapist carefully helps you into the exact position that you were in during the simulation process.
• The therapist leaves the room and turns on the machine that delivers the radiation (linear accelerator).
• Although the therapist isn't in the room during the treatment, you will be monitored from another room on a television screen. Usually you and the therapist can talk with each other through an intercom. If you feel sick or uncomfortable, be sure to tell your therapist. The machine can be stopped at any time.

Delivery of the radiation itself lasts only a few minutes, but the whole process may take 30 minutes to an hour for each visit.

Radiation therapy itself is painless. You may feel some discomfort while lying in the required position, but this is generally short-lived.

After the session is over, you're free to go about your regular activities. Generally no special precautions are needed.

In some cases, once the main radiation therapy sessions have been completed, a boost treatment to the tumor bed is recommended to further reduce the chances of recurrence. A radiation boost may be given with additional external radiation therapy sessions or with internal radiation therapy.

Internal radiation
For internal radiation, the radioactive seeds are inserted twice a day for a few minutes in the implanted radiation holders. This is usually done on an outpatient basis, and you can leave the facility between visits.

While the radioactive material is inside your body, people around you can be exposed to radioactivity. Once the pellets are removed, however, this risk goes away.

After the course of therapy is over, the holders are removed. Usually you're given pain medication before the holders are removed. The area may be sore or tender for a few months.

Methods of radiation delivery under study
Researchers are investigating several methods of radiation delivery that may result in fewer side effects and more convenient treatments.

One example is accelerated partial breast irradiation. This method targets radiation specifically at the breast area that contained the tumor, rather than the entire breast. It's also given in fewer, higher doses than standard external beam radiation therapy. Interstitial brachytherapy is considered a form of accelerated partial breast irradiation. For certain people with breast cancer — older women with small, isolated tumors and no lymph node involvement, for example — this method may be sufficient to prevent cancer recurrence. More research is needed, though, to determine whether long-term outcomes for these people are the same as outcomes when standard radiation therapy is used.

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