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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 and 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 prostate cancer that has spread to the bones
  • 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.

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Updated: 2 July 2012