Radiotherapy is a treatment where radiation is used to kill cancer cells.

There are many different ways you can have radiotherapy, but they all work in a similar way.

They damage cancer cells and stop them from growing or spreading in the body.

 

When radiotherapy is used

Radiotherapy may be used in the early stages of cancer or after it has started to spread.

It can be used to:

try to cure the cancer completely (curative radiotherapy)

make other treatments more effective – for example, it can be combined with chemotherapy (chemoradiation) or used before surgery (neo-adjuvant radiotherapy)

reduce the risk of the cancer coming back after surgery (adjuvant radiotherapy)

relieve symptoms if a cure isn’t possible (palliative radiotherapy)

Radiotherapy is generally considered the most effective cancer treatment after surgery, but how well it works varies from person to person.

Ask your doctors about the chances of treatment being successful for you.

Types of radiotherapy

Radiotherapy can be given in several ways. Your doctors will recommend the best type for you.

The most common types are:

radiotherapy given by a machine (external radiotherapy) - where a machine is used to carefully aim beams of radiation at the cancer

radiotherapy implants (brachytherapy) - where small pieces of radioactive metal are (usually temporarily) placed inside your body near the cancer

radiotherapy injections, capsules or drinks (radioisotope therapy) - where radioactive liquid is swallowed or injected into your blood

Treatment is usually given in hospital. You can normally go home soon after external radiotherapy, but you may need to stay in hospital for a few days if you have implants or radioisotope therapy.

Most people have several treatment sessions, which are typically spread over the course of a few weeks.

Read more about what happens during radiotherapy.

Side effects of radiotherapy

As well as killing cancer cells, radiotherapy can damage some healthy cells in the area being treated.

This can cause some side effects, such as:

sore, red skin

feeling tired most of the time

hair loss in the area being treated

feeling sick

losing your appetite

a sore mouth

diarrhoea

Many of these side effects can be treated or prevented and most will pass after treatment stops.

External radiotherapy doesn't make you radioactive, as the radiation passes through your body.

The radiation from implants or injections can stay in your body for a few days, so you may need to stay in hospital and avoid close contact with other people for a few days as a precaution.

Read more about the side effects of radiotherapy.