Brain radiotherapy and worsening symptoms | Cancer Research UK
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Brain radiotherapy and worsening symptoms

Nurse and patients talking about cancer

This page tells you about why your symptoms may get worse during brain radiotherapy. You can find out about


Worsening symptoms during brain radiotherapy

Some people find that their brain tumour symptoms get worse for a while after starting radiotherapy treatment. This can be frightening because you may think your treatment hasn't worked and that the tumour is growing. In fact, it is most likely to be due to the treatment.

Radiotherapy to the brain causes a short term swelling in the treatment area, which raises the pressure in the brain. Doctors call this oedema. It can make your symptoms worse for a time – for example, causing headaches, feeling sick, or fits (seizures). The swelling does go down, but while you have it your doctor will give you steroid tablets to take. Steroids reduce the swelling. You start to gradually lower the dose of steroids after the treatment ends. But if the swelling hasn't gone down enough, your symptoms may start to come back.

It is important to talk to your radiotherapy doctor (clinical oncologist), radiographer, or specialist nurse if you think your symptoms are getting worse. They will be able to reassure you and may increase your dose of steroid tablets until it gets better. If you are not able to take steroids for any reason your doctor may suggest a biological therapy drug called bevacizumab (Avastin). Bevacizumab can lower raised pressure in the brain by changing the growth of blood vessels around the tumour.


Getting more information about radiotherapy

We have detailed information about external radiotherapy  in this section. There is also detailed information about the side effects of radiotherapy.

In this section we have information about the other side effects of brain radiotherapy, including

You can phone the Cancer Research UK nurses on freephone 0808 800 4040. The lines are open from 9am to 5pm, Monday to Friday. They will be happy to answer any questions that you have.

Our general organisations page gives details of people who can provide information about radiotherapy. Some organisations can put you in touch with a cancer support group. Our cancer and treatments reading list has information about books, leaflets and other resources about radiotherapy treatment.

If you want to find people to share experiences with online, you could use Cancer Chat, our online forum.

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Updated: 7 May 2014