What internal radiotherapy is | Cancer Research UK
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What internal radiotherapy is

Nurse and patients talking about cancer

This page tells you about internal radiotherapy, which uses radioactive metals or liquids (isotopes) to treat cancer. There is information about the two main types of internal radiotherapy


Radioactive implants

Internal radiotherapy implants are radioactive metal wires, seeds, or tubes put into your body, inside or close to a tumour. This is called brachytherapy. The radioactive metal is called a source and is left inside the body for a period of time. In many types of cancer the source is taken out after a few minutes or a few days. While it is in place you will need to avoid close contact with people and may need to be looked after in a single room in hospital.

In some types of cancer, small metal implants, or seeds, are left in the body permanently. These implants are made of radioactive gold or contain radioactive iodine. They give a very high dose of radiation to the area of the cancer cells. For most types of implants the radioactivity only travels a few millimetres through body tissue and so it cannot be detected outside the body. For some people the radioactivity can be detected outside the body at first. They need to avoid close contact with people until the radioactivity drops to safe levels.


Radioactive liquids

Radioactive liquids to treat cancer are given either as a drink or by injection. Examples include

  • Radioactive phosphorus – used for blood disorders
  • Radioactive radium – used for cancer that has spread to the bones (secondary bone cancer)
  • Radioactive strontium – used for secondary bone cancers
  • Radioactive iodine – used for benign (non cancerous) thyroid conditions and thyroid cancer

The radioactive part of the liquid is called an isotope. It may be attached to another substance, which is designed to take the isotope into the tumour.


More information about internal radiotherapy

We have detailed information about the different types of internal radiotherapy in this section.

There is also detailed information about the side effects of radiotherapy.

You can phone the Cancer Research UK nurses on freephone 0808 800 4040. The lines are open from 9am to 5pm, Monday to Friday. They will be happy to answer any questions that you have.

Our general organisations page gives details of people who can provide information about radiotherapy. Some organisations can put you in touch with a cancer support group. Our cancer and treatments reading list has information about books, leaflets and other resources about radiotherapy treatment.

If you want to find people to share experiences with online, you could use Cancer Chat, our online forum.

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Updated: 30 April 2014