Internal radiotherapy

Internal radiotherapy uses a radioactive material that is put inside the body to treat cancer.
On this page

What is internal radiotherapy?

Internal radiotherapy uses a radioactive material that is put inside the body to treat cancer. This is called:

  • brachytherapy, when a solid material is used
  • radioisotope or radionuclide therapy, when a liquid is given by mouth or injection.

Your healthcare team can give you more information about these types of radiotherapy.

If you are having some types of internal radiotherapy, you may have to stay in hospital for a few days.

Is internal radiotherapy safe?

Your treatment is planned to give you the amount of radiation needed to treat the cancer safely and effectively. But your healthcare team are careful to protect other people around you from radiation.

Safety measures may be slightly different in different hospitals. Your team will explain what to expect.

Related pages

Brachytherapy

Brachytherapy uses radioactive sources that are put near or inside the tumour. These include:

  • seeds
  • pellets
  • tubes
  • plaques
  • discs.

The radioactivity only affects tissue that is very close to the source. This means the tumour is treated, but healthy areas around it get much less radiotherapy. Areas of the body that are further away are not affected at all.

The source is left in place to give the correct dose of treatment. Depending on the type of brachytherapy, this may take a few minutes or a few days. Some sources are designed to stay in the body permanently.

Your healthcare team will explain your treatment plan. This may also involve external beam radiotherapy before or after brachytherapy or other treatments such as chemotherapy, hormonal therapy or targeted therapy.

Brachytherapy is mainly used to treat cancers in the prostate, cervix and womb. It is sometimes used to treat other cancers, such as cancer of the vagina, vulva, oesophagus (gullet), skin and rectum.

Brachytherapy for prostate cancer

There are 2 ways of giving brachytherapy for prostate cancer.

  • Permanent seed implants

    Permanent seed implant treatment is sometimes known as low-dose-rate (LDR) brachytherapy. Small radioactive seeds are put into the prostate under a general anaesthetic or spinal anaesthetic. This is an injection of painkillers into the spine. The seeds are not removed. They are left inside the body permanently to release radiation slowly. The seeds become less radioactive over several months..

  • High-dose-rate (HDR) brachytherapy

    HDR brachytherapy is given under a general or a spinal anaesthetic. A spinal anesthetic is an injection of painkillers into the spine. Thin tubes are put through the skin and into position in the prostate.

    The ends of the tubes outside the body are connected to an HDR treatment machine. The machine sends a radioactive pellet into each tube. It keeps the pellets in the tubes in the prostate for up to an hour to give the treatment. When the treatment has finished, the pellets return to the machine. Sometimes 2 or 3 treatments are given over 24 hours. When all the treatment is finished, the tubes are removed..

Brachytherapy for cancers of the cervix, womb, vulva and vagina

Hollow tubes called applicators are placed into the vagina. One end of each tube sits inside the vagina or womb. The other end sits outside the body between the legs. If a tube is placed in the womb you may have a general anaesthetic or a spinal anaesthetic. A spinal anesthetic is an injection of painkillers into the spine.

The end of the tubes outside the body are connected to a treatment machine. The machine sends a radioactive pellet into each tube. The machine then gives the planned dose of radiation. When the treatment has finished the pellets return to the machine. The actual delivery of treatment will cause no pain or burns.

This type of brachytherapy can be given as:

  • high-dose-rate treatment (HDR)
  • pulsed-dose-rate treatment (PDR)
  • low-dose-rate treatment (LDR).

These methods all work equally well. The type you have depends on the system your hospital uses.

We have more information about brachytherapy for cervical cancer.

Other cancers and brachytherapy

  • Plaque brachytherapy

    Eye cancer (ocular melanoma) may be treated using a small radioactive disc called a plaque. The plaque is placed near the cancer using a small operation. It is usually done under a general anaesthetic. But sometimes a local anaesthetic is used. The plaque is left in place, usually for 1 to 5 days. You have another small operation to remove it after the treatment. .

  • Brachytherapy using an endoscope

    An endoscope is a thin, flexible tube with a camera on the end. It can be used to look inside areas such as the nose, throat, airways or rectum.

    An endoscope can be used to look for a tumour. When the tumour is found, the person doing the endoscopy puts a thin tube next to the tumour. A machine then sends radioactive pellets into the tube. It keeps the pellets in the tubes in place to give the treatment. After the treatment the pellets return to the machine.

    Your healthcare team will give you more information if you are offered this treatment.

  • Selective internal radiotherapy treatment (SIRT)

    This type of brachytherapy may be used to treat some types of liver cancer. For example, it may be used to treat cancer that spreads to the liver from the bowel. Tiny radioactive beads are injected into the bloodstream. They stick permanently in small blood vessels in and around the liver tumour. The beads give off radiation which damages the cancer cells.

    We have more information about SIRT.

Radiation safety during brachytherapy

You may have your treatment and go home on the same day or you may stay in hospital. This depends on the type of brachytherapy you have. 

During your treatment in hospital you may be looked after in a single treatment room. You may need to be alone in the room at times. Tell your healthcare team if you are worried about this so they can help.

As soon as the source is removed from your body, there is no risk to people around you. You are not radioactive.

For some types of brachytherapy, the source is not removed. This includes permanent seed implants or SIRT. The radiation from each source is absorbed by the area of the body closest to it. It is safe for you to be around most people. 

As a precaution, you may have to avoid close contact with children or people who are pregnant for a time. Your healthcare team will explain this and any other safety measures to you. They will give you information about your treatment to carry with you at all times.

Radioisotope therapy

This therapy uses radioactive liquids known as radioisotopes or radionuclides to destroy cancer cells. The liquid can be given:

  • by mouth as a drink or capsules
  • as an injection into a vein.

Cancer cells take in the radioisotope more than normal cells do. This means they get a higher dose of radioactivity. This eventually destroys the cancer cells.

Your radiotherapy team will tell you how you will have your treatment and any possible side effects.

Types of radioisotope therapy

  • Iodine-131

    This is the most common type of radioisotope therapy. It is mainly used to treat some types of thyroid cancer. You usually have it as capsules.

    It may also be used to treat other rarer neuroendocrine tumours (NETS). In this case you have it as an injection into a vein in the arm. You may have to stay in hospital to have this treatment.

  • Radium-223

    This radioisotope is sometimes used to treat prostate cancer that has spread to the bones. It may be used if hormone therapy alone is no longer controlling the cancer and chemotherapy has already been used or is not a suitable option. You have it as an injection into a vein. You can usually go home soon after having this treatment.

  • Lutetium-177

    Lutetium-177 is used to treat some neuroendocrine tumours (NETS). It may be used to treat other cancers. You have it as an injection into a vein. You usually stay in hospital for this treatment. 

Radiation safety during radioisotope therapy

After treatment, your body fluids are slightly radioactive for a time. Your healthcare team will give you instructions about using the toilet and cleaning up any spilled body fluids safely. 

You may be advised to avoid close contact with children or people who are pregnant for a time.

If your treatment involves a stay in hospital, you may be cared for in a single treatment room. You may be asked to stay in your room at all times. Tell your team if you are worried about this so they can help.

Your team will tell you any other safety measures you need to follow.

Getting support

Macmillan is here to support you. If you would like to talk, you can do the following:

About our information

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editor, Dr David Gilligan, Consultant Clinical Oncologist.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

Date reviewed

Reviewed: 01 August 2022
|
Next review: 01 August 2025
Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

This means it is easy to use, up-to-date and based on the latest evidence. Learn more about how we produce our information.

Print page

How we can help

Macmillan Support Line
The Macmillan Support Line is a free and confidential phone service for people living and affected by cancer. If you need to talk, we'll listen. 

 

Call us on 0808 808 00 00
8am to 8pm. It's free to call from landlines and mobiles within the UK.
Email us
Get in touch via this form
Chat online
Every day 8am - 8pm.
Online Community

Chat online anonymously to others who understand what you are going through. Our community is available 24/7 and has dedicated forums where you can get advice and ask our experts.
Help in your area
What's going on near you? Find out about support groups, where to get information and how to get involved with Macmillan where you live.