Sarah Cannon - November 01, 2021

Internal radiation (also called brachytherapy) is used to treat different types of cancer by placing radioactive material inside or near the tumor to kill cancer cells and shrink the tumor. Brachytherapy delivers a higher dose of radiation to a smaller area of the body in a shorter amount of time than traditional external radiation treatment.

With brachytherapy, an implant is placed in the body temporarily or permanently using an implant like a:

  • Balloon
  • Capsule
  • Needle
  • Pellet
  • Ribbon
  • Seed
  • Tube
  • Wire

There are two internal radiation methods:

  • Interstitial radiation: The implant is placed inside or close to the tumor.
  • Intracavitary radiation: The implant is placed inside a body cavity, like the uterus or bladder.

How does internal radiation work?

Internal radiation implants are typically placed during a surgical procedure in an operating room. You’ll get either local anesthesia (where a body part is numbed) or general anesthesia (where you’re put into a state of deep sleep), so you don’t feel any pain.

Your radiation oncologist will use imaging tests (like an X-ray, CT scan, MRI or ultrasound) to help place the implant.

Your medical team may wear special protective gear to avoid radiation exposure.

Temporary vs. permanent brachytherapy

Depending on your diagnosis, your radiation oncologist may recommend either a temporary or permanent implant. Permanent implants give off radiation for a certain amount of time and, eventually, the radiation fades away.

Temporary implants are placed in the body for a few minutes or days. There are two forms of temporary internal radiation:

  • High-dose-rate (HDR) brachytherapy: HDR brachytherapy is used for a few minutes at a time. It may be repeated once or twice a day for a few days or weeks. The implant is removed after each treatment session. HDR brachytherapy is typically done as an outpatient procedure.
  • Low-dose-rate (LDR) brachytherapy: This treatment involves giving lower doses of radiation over a longer period of time (typically one to a few days). Then, the implant is removed. You’ll likely have to stay in the hospital during this type of treatment.

With both temporary and permanent brachytherapy implants, you may need to take special precautions to avoid exposing others to radiation, such as limiting contact with children and pregnant women immediately after treatment.

Is internal radiation safe?

Yes, internal radiation is safe for appropriate candidates, though it does come with some side effects, including:

  • Irritation or soreness in the treated area
  • Fatigue
  • Diarrhea
  • Nausea
  • Low blood counts

Who is a candidate for internal radiation?

Brachytherapy is used to treat the following types of cancer:

  • Breast cancer
  • Cervical cancer
  • Eye cancer
  • Gallbladder cancer
  • Head and neck cancer
  • Lung cancer
  • Prostate cancer
  • Rectal cancer
  • Skin cancer
  • Uterine cancer
  • Vaginal cancer

Your radiation oncologist will work with your care team to determine if you’re a good candidate for internal radiation. If you have questions about your treatment options, talk to your oncology team.

Learn more about radiation therapy at Sarah Cannon.


National Cancer Institute

American Cancer Society - Internal Radiation

American Cancer Society - Radiation