Brachytherapy is when your doctors treat the cancer by inserting radioactive material directly into the affected area. A high dose of radiation is given to the tumour, but healthy tissue only gets a small amount of radiation.

Brachytherapy is usually used to treat prostate cancer, cervical and womb cancer. It’s also used to treat other cancers such as head and neck cancers.

How it’s given depends on the type of cancer being treated.

  • Prostate cancer - small radioactive seeds are inserted either directly into the tumour or into a catheter in the prostate.
  • Cervical and womb cancer – applicators are placed inside the womb or vagina. Radioactive material is inserted inside the applicators.
  • Mouth, cervical, breast and other cancers - very thin radioactive needles, wires or tubes are inserted into the tumour. This is done under a general anaesthetic.
  • Secondary liver cancer - radioactive beads are inserted into the blood vessels using a catheter.

What is brachytherapy?

Brachytherapy gives a high dose of radiotherapy directly to the tumour but only a low dose to normal tissues. It’s mainly used to treat cancers in the prostate gland, cervix and womb but it may also be used to treat some other cancers, such as head and neck cancers. Brachytherapy may be given in addition to external radiotherapy.

Brachytherapy for prostate cancer

There are two ways of giving brachytherapy for prostate cancer. Small radioactive seeds can be inserted into the tumour and left to release their radioactivity slowly. This is sometimes known as low-dose rate treatment. The seeds are not removed and the radiation gradually fades away over about six months. All the radioactivity is absorbed by the prostate, so it’s safe for you to be around other people. As a precaution, you’ll be advised to avoid long periods of close contact with children and pregnant women. Your specialist will give you more information about the precautions you should take.

Alternatively, the seeds can be placed inside special catheters that have been inserted into the prostate gland while you’re asleep in an operating theatre. The seeds are put into the catheters for a set period of time and are then taken out. This is known as high-dose rate treatment. After the treatment, the catheters are removed and no radioactive material is left in the prostate gland.

Brachytherapy for cervical and womb cancer

Brachytherapy for cervical or womb cancer is given through specially designed hollow tubes called applicators, which are inserted into the womb or vagina. During treatment, a machine is used to place the radioactive material inside the applicators. After the treatment, the radioactive material is withdrawn back into the machine and the applicators are removed.

The brachytherapy may be given as either high-dose or low-dose rate treatment. With both treatments, the same dose of radiotherapy is given but over different times. High-dose rate treatment is given over a short period of time (for example, 10–20 minutes), either as one short burst or several short bursts over a few days. Low-dose rate treatment is given over a longer period of time, usually over 12–24 hours.

You’ll be cared for in a single room while you’re having brachytherapy. Special precautions will need to be taken to prevent other people being exposed to radioactivity while the machine is giving you your treatment. Your hospital team will give you more detailed information about these precautions.

Women who have high-dose rate treatment for cervical cancer may have image guided brachytherapy (IGBT). IGBT makes the radiotherapy treatment very accurate. It uses CT or MRI imaging to pinpoint exactly where the cancer is before each treatment. This makes it possible to shape the radiation dose to match the shape of the tumour and to avoid organs such as the bowel and bladder. Sometimes additional applicators may be used to boost the dose of radiotherapy to a particular area.

IGBT that uses MRI images is particularly accurate but it isn’t widely available in the UK. The Royal College of Radiologists and the Department of Health recommend that women with cancer of the cervix should be offered MRI-based IGBT from 2015.

Your oncologist can tell you whether IGBT is a suitable treatment for you. They can arrange for you to have IGBT at another treatment centre if it’s not possible for you to have it at your local one.

Brachytherapy using caesium or iridium wires

This can be used to treat a number of different cancers including cancers of the mouth, lip, cervix and breast. Very thin radioactive needles, wires or tubes are inserted while you’re under a general anaesthetic in an operating room. If you need to have this type of treatment, your healthcare team will discuss this with you and give you detailed information about it.

We have more information about brachytherapy for prostate cancer, cervical cancer, womb cancer and head and neck cancers.

Selective internal radiotherapy treatment (SIRT)

SIRT is a specialised type of brachytherapy that uses radioactive beads to treat cancers that have spread to the liver (secondary cancer in the liver).

SIRT is a way of delivering high-dose internal radiotherapy. It’s only suitable for some types of secondary liver cancer, for example, those that have spread to the liver from the bowel (colon or rectum). It uses tiny beads called microspheres, which contain a radioactive substance called Yttrium-90. Cancer cells need a blood supply to receive oxygen and nutrients. SIRT beads lodge in the blood vessels that supply tumours. They destroy the blood vessels and stop the flow of blood to tumours so that they die. This is called radioembolisation.

Back to Internal radiotherapy explained


Radioisotope therapy targets cancer cells with a radioactive liquid.