Radiotherapy is used in a number of different ways to help treat mesothelioma.

For people who have pain in their chest due to a mesothelioma, giving a short course of radiotherapy (usually no longer than 2 weeks) can help improve discomfort in the majority of people.

If there are swellings in the skin covering the chest, due to mesothelioma, then a short course of radiotherapy can shrink them, and help keep them under control for a time, in about half of the people treated.

Unfortunately, breathlessness, which is a common symptom of mesothelioma, is not usually helped by radiotherapy.

If a drain is put into the chest to remove fluid, or a needle is inserted to take a biopsy (a sample of tissue for examination under the microscope) then mesothelioma cells can track along the wound left by the drain, or the needle. These cancer cells may then grow and cause pain. In this situation, giving a small dose of radiotherapy to the drain/needle site after removal can help prevent this happening, but the treatment must be given within a few weeks of the drain or needle being removed if it is to be effective.

The most effective treatment for a mesothelioma is an operation to remove the tumour. It is thought that giving radiotherapy afterwards might improve the chance of a cure, but the benefit of radiotherapy in this situation is still unclear. Trials are ongoing to try and answer this question.

However, most people with mesothelioma have tumours that have spread too far to operate on by the time their cancer is diagnosed. Unfortunately, radiotherapy given to tumours that can't be removed by surgery, does not appear to help control them or increase life-expectancy, but, may help relieve unpleasant symptoms.