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About internal radiotherapy

There are different types of internal radiotherapy treatments. Different types are used for different types of cancer.

Internal radiotherapy gives radiation from inside the body. 

Some types use radioactive liquids as a capsule or drink. Others are injected into a vein.

Some types are called brachytherapy and they use radioactive metal put inside the body close to the area of the cancer.

Radioactive liquids

You have the radioactive liquid as a drink or as an injection into a vein. Examples include:

  • radioactive phosphorus – used for blood disorders
  • radioactive radium – for cancer that has spread to the bones (secondary bone cancer)
  • radioactive strontium – 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.

Radioactive implants

Internal radiotherapy implants are radioactive metal wires, seeds, or tubes. They are put into your body, close to a tumour or in the area where a cancer was removed.

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 need to avoid close contact with people and might 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 can't 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 a safe level.

Information and help

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