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Internal radiotherapy

Internal radiotherapy means giving radiotherapy to the cancer from inside. It is also called brachytherapy.

Internal radiotherapy uses a radiation source inside your body. The radiation source is the substance that gives off the radiation.

It may be positioned actually within the cancer or very close to it. This way the tumour gets a high dose of radiation without damaging surrounding tissue. 

When you have it

You can have internal radiotherapy:

  • on its own to treat a small tumour
  • if your cancer has come back after earlier treatment with external radiotherapy
  • as a booster dose at the end of a course of external radiotherapy

Benefits of having internal radiotherapy

The benefits of using internal radiotherapy for mouth and oropharyngeal cancer are:

  • less physical changes and loss of everyday function in the treatment area compared to other treatments 
  • nearby structures such as the brain, spinal cord, and eyes don't receive high doses of radiation
  • higher doses can be used for tumours that can't be treated any more with external radiotherapy 

Types of internal radiotherapy

There are different types of internal radiotherapy including:

  • radioactive permanent implants
  • interstitial radiotherapy

Radioactive permanent implants

What it is

These small radioactive pellets are about the size and shape of a grain of rice. They are usually made of gold. The doctor puts these pellets into the cancer during a small operation. The pellets stay there forever (permanently). 

The pellets contain a small level of radiation which eventually loses its strength over a few weeks. The radiation can only travel a short distance and the tumour gets nearly all the dose, with very little effect on surrounding tissues and organs. 

This type of brachytherapy can often cure small tumours in the lip, tongue, soft palate, cheeks, neck, tonsil or floor of the mouth. 

What happens

You go into hospital. The doctor places the pellets in the tumour when you are under a general anaesthetic. You have to stay in hospital in an isolated room for one night after your operation. The radioactivity in the pellets is at its strongest and other people can't be exposed to the radiation. 

Afterwards you can go home. The radiation is not a risk to anyone else around you. Your doctor will arrange a CT scan about 6 weeks after your operation. This is to check the pellets are in the correct place and haven't moved. 

An alert card tells other people that you have the radioactive pellets inside your body. You should show this to your dentist or hospital staff when you have a procedure. Tell your relatives about this card, in case you end up in hospital and cannot give the information yourself. 

Interstitial radiotherapy

What it is

For interstitial radiotherapy, the doctor places thin tubes into your tumour. They then connect the tubes to a brachytherapy machine to deliver radiotherapy directly into your tumour. 

What happens

You have interstitial radiotherapy under a general anaesthetic. The doctor puts a number of hollow thin tubes directly into your tumour. To check the position you will have an x-ray. 

A radiographer connects the tubes to a brachytherapy machine. It contains a radioactive metal ball which travels out of the machine, into the tubes and releases high doses of radiotherapy directly into your tumour. You can have up to 2 treatments a day. 

The treatment length varies:

  • if the implants are a booster treatment after external radiotherapy the implants may stay in place for up to 2 days
  • if the implants are your only treatment they may stay in place for between 3 to 5 days 

Treatment sessions do not last long, but you have to be alone whilst having treatment. The radiographers watch you on a TV screen, from outside the room. 

You have another general anaesthetic so the doctor can take out the tubes. You are likely to feel sore for up to 2 or 3 weeks after the doctors remove the implant. 

Planning the treatment

You have a planning CT scan in the radiotherapy department. The scan shows the cancer and the area around it.

Photo of a CT scanner

The radiographers put some markers on your skin. You need to lie very still.

Once you are in position the radiographers move the couch up and through the scanner. The radiographers leave the room and the scan starts.

The scan takes about 5 minutes. You won't feel anything. The radiographers watch from the next room.

Before the planning appointment you might also have other scans, such as an MRI scan.

Your treatment team puts all the scans together in a special computer to decide your radiotherapy plan. 

Last reviewed: 
14 Oct 2014
  • The Royal Marsden Hospital Manual of Clinical Nursing Procedures (8th Edition) 
    L Dougherty and S Lister. (Editors)

    Wiley-Blackwell, 2011   

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