Internal radiation therapy (brachytherapy)

Internal radiation is also called brachytherapy. It uses a radioactive source that’s put inside the body in or near the tumor.

What is internal radiation therapy?

Internal radiation therapy uses a radiation source that’s usually sealed in a small holder called an implant. The implant is placed very close to or inside the tumor, so that it harms as few normal cells as possible. Internal radiation therapy allows a higher dose of radiation in a smaller area than might be possible with external radiation treatment.

The main types of brachytherapy are intracavitary radiation and interstitial radiation. Both of these methods use radioactive implants such as pellets, seeds, ribbons, wires, needles, capsules, balloons, or tubes.

  • During intracavitary radiation, the radioactive source is placed in a cavity (space) in the body, such as the rectum or uterus.
  • With interstitial radiation, the implants are placed in or near the tumor, but not in a body cavity.

How are implants placed in the body?

Before being put in the body, the implants are kept in containers that hold the radiation inside so it can’t affect others. You will likely be treated in a room that also contains the radiation. The health professionals handling the implants may wear special gear that protects them from exposure once the implants are taken out of the container.

Sealed radioactive substances are put into body cavities or body tissue with applicators, which are often metal tubes or plastic tubes called catheters. These are typically put in place in a hospital operating room. You’ll get anesthesia, which may be either general (where drugs are used to put you into a deep sleep so that you don’t feel pain) or local (where part of your body is numbed). The doctor usually puts the applicators in using an imaging test (such as an x-ray or MRI) to find the exact place they need to go.

How long do implants stay in place?

The radioactive implants are put into the body through the applicator(s). Some implants are permanent. They are put in through the applicator and then the applicator is removed. Other implants are left in only for a certain amount of time. If the implants will be removed but then put in again later, the applicator is often left in until the treatment is finished (stitches may be used to keep it in place). The applicator is then removed when the implants are taken out for the last time.

The type of implant you receive and your treatment schedule will depend on the kind of cancer, where it is in your body, your general health, and other treatments you have had.

High-dose rate brachytherapy

High-dose-rate (HDR) brachytherapy allows a person to be treated for only a few minutes at a time with a powerful radioactive source that’s put in the applicator. The source is removed after several minutes. This may be repeated over the course of a few days to weeks. The radioactive material is not left in your body. The applicator might be left in place between treatments, or it might be put in before each treatment.

Low-dose-rate brachytherapy

In this approach, the implant gives off lower doses of radiation over a longer period of time.

Some temporary implants are left in from 1 to a few days. You’ll probably have to stay in the hospital, sometimes in a special room, during treatment. For larger implants, you might have to stay in bed and lie fairly still to keep it from moving.

Some smaller implants (such as the seeds or pellets) are left in place – they’re never taken out. Over the course of several weeks they stop giving off radiation. The seeds are about the size of rice grains and rarely cause problems. If your implants are to be left in, you may be able to go home the same day they’re put in.

How will I feel during implant therapy?

You’re not likely to have a lot of pain or feel sick while implants are being put in. The drugs used while they’re being placed might make you feel drowsy, weak, or sick to your stomach, but these side effects don’t last long. If your implant is held in place by an applicator, you may have some discomfort in that area. Ask for medicine to help you relax or to relieve pain if needed. Be sure to tell your cancer care team if you have any burning, sweating, or other symptoms.

What happens after a temporary implant is removed?

In most cases, anesthesia is not needed when the applicator and/or implant is removed. It’s usually done right in your hospital room. The treated area may be sore or tender for some time after treatment, but most people can return to normal activities quickly. Keep in mind that your body is recovering from radiation treatments, and you may need extra sleep or rest breaks over the next few days.

What happens to permanent implants?

The radioactive materials stop giving off radiation over time. It may take weeks or months. Talk to your cancer care team about how long it will take in your case. Once the radiation is gone, the implant(s) are no longer active. They usually stay in place and cause no harm, so there’s no need to take them out.

Will I be radioactive during or after internal radiation treatment?

With internal radiation therapy, your body may give off a small amount of radiation for a short time.

If the radiation is contained in a temporary implant, you’ll be asked to stay in the hospital and may have to limit visitors during treatment. You also may be asked to stay a certain distance away from them. Pregnant women and children may not be allowed to visit you. Your body fluids are not radioactive. Once the implant is removed, your body will no longer give off radiation.

Permanent implants give off small doses of radiation over a few weeks to months as they slowly stop giving off radiation. The radiation usually doesn’t travel much farther than the area being treated, so the chances that others could be exposed to radiation is very small. Still, your health care team may ask you to take certain precautions such as staying away from small children and pregnant women, especially right after you get the implants. Again, body fluids and the things you use will not be radioactive.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master’s-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Medical Review: June 30, 2015 Last Revised: June 30, 2015

American Cancer Society medical information is copyrighted material. For reprint requests, please see our Content Usage Policy.