Types of radiotherapy
There are two main types of radiotherapy which use different methods to introduce radiation to the body.
The two main types of radiotherapy are:
External radiotherapy – where the radiation comes from a machine outside the body.
Internal radiotherapy – where the radiation comes from implants or liquids placed inside the body.
External radiotherapy is the most common type of radiotherapy used. It is usually given as a course of several treatments over days or weeks.
External radiotherapy is usually given during outpatient visits to a hospital cancer centre. A machine directs the high-energy radiation, usually X-rays, at the cancer site and a small area of normal tissue surrounding it. You will be positioned carefully on a treatment couch and then the machine will be directed exactly at the area to be treated, often from different angles. Treatment takes several minutes and is painless.
Before you start your course of radiotherapy you will usually need to attend the hospital for treatment planning.
The CyberKnife is a sophisticated robotic external radiotherapy system given over a shorter period of time. However, it is not suitable for all tumours and you can ask your doctor if your case is suitable.
External radiotherapy doesn’t make you radioactive and you can safely mix with other people, including children, at any time during your treatment.
Internal radiotherapy can be given in several ways.
Brachytherapy is treatment in which solid radioactive sources are placed inside a body cavity or needles are placed in the tumour. This is usually given on an outpatient basis but may involve staying in hospital for a few days until the radioactive source has been removed.
Another type of internal radiotherapy involves using a liquid source of radiation and is called radionuclide (radioisotope or unsealed source) therapy. It can either be taken by mouth or given as an injection into a vein. For this type of treatment, you will need to stay in hospital for a few days until most of the radioactivity has disappeared from your body.
If you are going to have internal radiotherapy, your doctor will discuss this with you and give you further information.
Occasionally, with radioactive treatment or with treatment with radioactive 'seeds', you will be emitting a certain amount of radioactivity for a few days. This is why there may be temporary restrictions on your movements and visitors. This will be carefully explained to you.