Getting Internal Radiation Therapy (Brachytherapy)
Internal radiation is also called brachytherapy. A radioactive implant is put inside your body in or near the tumor. Getting the implant is usually painless. Depending on your type of cancer and treatment plan, you might get a temporary or a permanent implant.
Learn more about how internal radiation therapy works, how implants are placed, and what to expect when you get this type of treatment.
- What is internal radiation therapy?
- How are implants placed in the body?
- How long do implants stay in the body?
- How will I feel during implant therapy?
- What happens after a temporary implant is removed?
- What happens to permanent implants?
- Will I be radioactive during or after internal radiation treatment?
- Learn more
What is internal radiation therapy?
Internal radiation therapy (brachytherapy) allows a higher dose of radiation to be given in a smaller area. The radiation source is usually sealed in a small holder called an implant.
Different types of implants have different names. Yours might be called pellets, seeds, ribbon, wires, needles, capsules, balloons, or tubes.
Where do the implants go?
The implants are placed in your body, very close to or inside the tumor. This way, the radiation harms as few normal cells as possible.
- Intracavitary radiation: The radioactive source is put in a body cavity (space), such as the rectum or uterus.
- Interstitial radiation: The implants are put in or near the tumor but not in a body cavity.
How are implants placed in the body?
Implants are usually placed in the hospital. You will probably be in a special operating room meant to keep the radiation inside the room.
You’ll get either:
- General anesthesia: Medicine that puts you into a deep sleep so you don’t feel pain OR
- Local anesthesia: Medicine that numbs part of your body
One or more implants are put into your body with an applicator, usually a metal or plastic tube called a catheter. Imaging tests (x-ray, ultrasound, MRI, or CT scan) are usually done during the procedure to find the exact placement for the implant.
The implants are brought into the operating room in special containers that hold the radiation inside, so it can’t affect others. The care team handling the implants may wear special protective gear.
How long do implants stay in the body?
The length of time your implant is left in place depends on the type of brachytherapy. Some implants are permanent. Others are removed after a few minutes or days.
See below for more information. But in general, you can expect:
- High-dose rate brachytherapy: 10–20 minutes, 1 or 2 times a day. Implants don’t stay in your body.
- Low-dose-rate brachytherapy: 1–2 days or permanently. If permanent, implants stop giving off radiation after several weeks.
The type of implant you get depends on your type of cancer, where it is in your body, your general health, and other treatments you’ve had. If an implant is permanent, the radiation fades over time. At some point, it won’t give off any more radiation.
Implants for high-dose rate brachytherapy (HDR)
If you get HDR brachytherapy, a strong radioactive source is put into your body with an applicator. The source is removed after 10 to 20 minutes. This may be repeated twice a day for a few days or once a day for a few 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.
You might stay in the hospital if you get twice-a-day treatments and the applicator is left in place.
Safety measures: You may need to take special precautions after treatment. Talk to your cancer care team about this.
Implants for low-dose rate brachytherapy (LDR)
With LDR, the implant gives off lower doses of radiation over 1-2 days and then is removed.
During treatment, you’ll probably stay in the hospital, sometimes in a special room. For larger implants, you might have to stay in bed and lie still to keep the implant from moving.
Some smaller implants (such as seeds or pellets) are left in place and never taken out. Over the course of several weeks, they stop giving off radiation. The seeds or pellets are about the size of rice grains and rarely cause problems. If your implants are left in, you may be able to go home the same day.
Safety measures: You may need to take special precautions. Talk to your cancer care team about this.
How will I feel during implant therapy?
You most likely won’t have a lot of pain or feel sick while implants are being put in. You might feel drowsy, weak, or sick to your stomach from the medicines used to keep you comfortable. 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.
- If you have to stay in bed for a few days (because of your type of implant), you may have aches and pains from being inactive.
Ask for medicine to help you relax or to relieve pain if needed. Tell your cancer care team if you have burning, sweating, or other symptoms.
What happens after a temporary implant is removed?
In most cases, you won’t need anesthesia when the applicator and/or implant is removed. It’s usually done in your hospital room. The treated area may be sore or tender after treatment, but most people can return to normal activities quickly.
Keep in mind that your body is recovering from radiation treatments. You may need extra sleep or rest breaks over the next few days.
What happens to permanent implants?
If your implants are left inside your body, the radioactive materials stop giving off radiation over time. It may take weeks or months. Ask your cancer care team how long it will take in your case.
Once the radiation is gone, the implants 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.
Temporary implants
If you have a temporary implant, you’ll stay in the hospital. You might have to limit visitors during treatment. You also may need to stay a certain distance away from them. Pregnant women and children might not be allowed to visit you.
- Depending on the type of implant, once it is removed, your body will likely no longer give off radiation.
Permanent implant
Over a few weeks to months, permanent implants slowly stop giving off radiation.
- The radiation usually doesn’t travel much farther than the treatment area, so the chance of other people being exposed is very small.
Your cancer care team might still ask you to take precautions, like staying away from small children and pregnant people, especially right after you get the implants.
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- References
Developed by the 绿帽社 medical and editorial content team with medical review and contribution by the American Society of Clinical Oncology (ASCO).
American College of Radiology and the Radiological Society of North America. Brachytherapy. Accessed at https://www.radiologyinfo.org/en/info/brachy on April 8, 2025.
American College of Radiology and the Radiological Society of North America. Radiation therapy. Accessed at https://www.radiologyinfo.org/en/info/intro_onco#112cb6e353d24b5c99f43511a2b1b884 on April 4, 2025.
American Society of Clinical Oncology (ASCO). Side effects of radiation therapy. Accessed at cancer.net. Content is no longer available.
American Society of Clinical Oncology (ASCO). What to expect when having radiation therapy. Accessed at cancer.net. Content is no longer available.
Fournier, DM. Radiation therapy. In: Maloney-Newton S, Hickey M, Brant JM, eds. Mosby’s Oncology Nursing Advisor: A Comprehensive Guide to Clinical Practice. 3rd ed. St. Louis: Elsevier; 2023: 322-338.
Last Revised: June 9, 2025
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