Tests and Procedures

Radiation therapy for breast cancer

What you can expect

Radiation therapy usually begins three to eight weeks after surgery unless chemotherapy is planned. When chemotherapy is planned, radiation usually starts three to four weeks after chemotherapy is finished. You will likely have radiation therapy as an outpatient at a hospital or other treatment facility.

A common treatment schedule (course) historically has included one radiation treatment a day, five days a week (usually Monday through Friday), for five or six weeks. This course is still commonly used in people who require radiation to the lymph nodes.

Increasingly, doctors are recommending shorter treatment schedules (hypofractionated treatment). Whole-breast irradiation can frequently be shortened to one to four weeks. Partial-breast irradiation may be completed in five days or less. These hypofractionated treatment schedules work as well as the longer one and may reduce the risk of some side effects. Your radiation oncologist can help decide the course that is right for you.

During external radiation

A typical external 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.
  • The radiation therapist helps you into the position you were in during the simulation process.
  • The therapist may take images or X-rays to ensure that you are positioned correctly.
  • 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, he or she will monitor you from another room on a television screen. Usually you and the therapist can talk through an intercom. If you feel sick or uncomfortable, tell your therapist, who can stop the process if necessary.

Delivery of the radiation may last only a few minutes, but expect to spend 15 to 45 minutes for each session, as it can take several minutes to set you up in the exact same position each day. This step ensures precise radiation therapy delivery.

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

After the session, you're free to go about your regular activities. Take any self-care steps at home that your doctor or nurse recommends, such as taking care of your skin.

In some situations, once the main radiation therapy sessions have been completed, your doctor may recommend a radiation boost. This commonly means additional fractions of radiation directed at the place of highest concern or four to five additional days of treatment. For example, after whole-breast irradiation is complete, a boost of radiation is commonly given to the area where the cancer was removed.

During internal radiation

For internal radiation, the radioactive source is inserted once or twice a day for a few minutes in the implanted radiation delivery device. This is usually done on an outpatient basis and you can leave between sessions.

After the course of treatment, the radiation delivery device is removed. You may be given pain medication before this happens. The area may be sore or tender for several days or weeks as the tissue recovers from the surgery and radiation.