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Side-effects of Proton Beam Therapy (PBT)

One of the key advantages of proton beam therapy over conventional radiotherapy is that it is more targeted. It does less damage to the healthy tissue around the tumour and the rest of the brain. This means it causes fewer side-effects, however, there are a few side-effects which are not uncommon.

What are the short term proton beam therapy side-effects?

What are the longer term proton beam therapy side-effects?

Will I be radioactive after treatment?

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What are the short term proton beam therapy side-effects?

The following side-effects are usually temporary and often disappear after treatment has finished:

  • fatigue
  • redness that resembles sunburn – this can appear in the area where the proton beam was directed
  • hair loss.

What are the longer term proton beam therapy side-effects?

Longer-term effects after PBT treatment in children can include hearing loss, which can be severe, and cognitive impairment, particularly in thinking speed and understanding language.

Hormone levels can be affected in up to 55% of children, with growth hormone being the most commonly affected.

However, all these effects are also possible side-effects of conventional radiotherapy. Ask your radiotherapy team about any side-effects you or your child may experience.

Will I be radioactive after treatment?

No, you do not need to take special precautions when you leave the hospital – it is safe to be around others, including children. Proton beam therapy targets the tumour inside your body with minimal impact on surrounding areas. After each treatment, there’s no risk of radiation remaining to affect anyone else.

There are currently two NHS high energy proton beam therapy centres and one low energy proton beam therapy centre in the UK serving patients with different types of cancer and tumours. Also, NHS proton beam therapy programme explains how the treatment works.


Download our Proton Beam Therapy factsheet

Proton Beam Therapy factsheet – PDF

Get more information about Proton Beam Therapy by downloading our full Proton Beam Therapy factsheet.


If you have further questions, need to clarify any of the information on this page, or want to find out more about research and clinical trials, please contact our team:

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