Radiotherapy treats cancer by using high-energy x-rays to destroy the cancer cells while doing as little harm as possible to normal cells. Radiotherapy is usually given to help relieve symptoms such as pain and breathlessness, but is sometimes given as part of treatment to try to cure mesothelioma.

Often, only one or a few treatments are needed, but occasionally a course of treatment is given over two weeks or so.

Radiotherapy can sometimes shrink or reduce the size of mesothelioma. This can help with symptoms like pain and discomfort, or breathlessness. Radiotherapy may also be given to the chest wall at the place where a biopsy has been done or a drainage tube has been inserted. In this situation, the radiotherapy prevents the tumour from growing out through the scar. Only one dose is given and the planning discussed below is not needed.

You may be given radiotherapy as an initial form of treatment or as a follow-up after surgery.

Your radiotherapy has to be carefully planned in order to make sure that you get maximum benefit from it. On your first visit to the radiotherapy department you will be asked to lie under a large machine called a simulator, which takes x-rays of the area to be treated. Sometimes a CT scanner can be used for the same purpose. Your treatment will be planned and supervised by a clinical oncologist (a doctor who is a specialist in radiotherapy treatment). 

Before each session of radiotherapy, the radiographer will position you carefully on the couch – either sitting or lying – and make sure you are comfortable. During your treatment, which only takes a few minutes, you will be left alone in the room but you will be able to talk to the radiographer, who will be watching you carefully from the next room. Radiotherapy is not painful but you do have to stay still for a few minutes while your treatment is being given.

Radiotherapy can cause general side effects such as feeling sick (nausea), being sick (vomiting) and tiredness. It can also make you temporarily more breathless and can cause flu-like symptoms for a few days, or chest pain. These side effects can be mild or more troublesome, depending on the strength of the radiotherapy dose and the length of your treatment. Your radiotherapist will be able to advise you what to expect.

Nausea can usually be effectively treated by anti-sickness drugs (called anti-emetics), which your doctor can prescribe.

If you don't feel like eating, you can replace meals with nutritious, high-calorie drinks that are available from most chemists and can be prescribed by your GP. Our section eating well has some helpful hints on how to eat well when you are feeling ill.

As radiotherapy can make you feel tired, try to get as much rest as you can, especially if you have to travel a long way for treatment each day.

All these side effects should disappear gradually once your course of treatment is over, but it is important to let your doctor know if they continue. Radiotherapy does not make you radioactive and it is perfectly safe for you to be with other people, including children, throughout your treatment.