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Side-effects of radiotherapy for children

Radiotherapy works because it has the greatest damaging effect on rapidly dividing cells such as tumour cells. But, it can also affect normal cells within the treatment area. This is what can lead to side-effects of radiotherapy for children.

Generally, the more immediate side-effects will gradually disappear within 6-12 weeks after treatment finishes. 

Your child’s health team will discuss possible side-effects with you before your child has treatment. You should ask them any questions to make sure you understand. You’ll be asked to sign a consent form indicating that you have understood and agreed to what they’ve explained.

You can speak to them at any time about any concerns you have or side-effects of radiotherapy your child is experiencing.

On this page:
What are the common side-effects of radiotherapy for children with a brain tumour?
Hair loss
Skin sensitivity
Nausea and vomiting
Reduced appetite
Will there be any long-term side-effects of radiotherapy for children?
Brain development, cognitive skills and emotions
Growth and development
Other possible long-term side effects of radiotherapy for children

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What are the common side-effects of radiotherapy for children with a brain tumour?

Common side-effects of radiotherapy for children with a brain tumour include:

It is very likely that your child will feel tired during their treatment. As the weeks of radiotherapy go on, this tiredness could increase.

This may be because their body is using its resources to repair any damage to healthy cells caused by the radiotherapy. Or because of all the journeys to and from the hospital.

Unfortunately, the feeling of tiredness does not stop immediately. Once the treatment stops and could continue for a number of weeks.

Encourage your child to rest or nap when they need to. And try to plan rest breaks into their days even if they are not feeling tired. A gentle walk from time to time can also be helpful.

Children who have received radiotherapy targeted at a large area of their brain can get something health professionals call ‘somnolence syndrome’.

This is a form of extreme tiredness and can occur several weeks after finishing radiotherapy. Just as you think your child is getting over the treatment. Your child may sleep a lot for 1–2 weeks, but they will recover.

Unfortunately, your child will lose some hair during radiotherapy. This can be quite distressing, particularly for older children and teenagers, and also for you.

Knowing that there will be some hair loss means that you can plan ahead and prepare your child. You can talk to your child’s radiographer about where your child is most likely to lose hair to help them prepare for this.

Generally, your child will only lose hair from the place where the radiotherapy beam enters and leaves the head. If your child has whole brain radiotherapy, however, they’re likely to have hair loss from their whole head.

Hair loss usually starts around two or three weeks after treatment starts.

Most hair will grow back in time, but it may not be as thick as it was before or it may have a different texture e.g. curly when it was straight before.

Sometimes hair loss can be permanent, depending on the dose of radiotherapy your child receives.

There are lots of places that sell hats, bandanas or wigs and hairpieces as practical suggestions for coping with hair loss. Some specialise in headwear for children.

Your child will be entitled to a free synthetic wig on the NHS if they’re under the age of 16, or under 19 and in full-time education. Ask their health team for more information. You can find a list of organisations that provide or sell wigs and headwear in the downloadable document at the bottom of this page.

During, or a few weeks after, radiotherapy, some children develop changes to their skin in the area where the treatment was i.e. on their scalp.

These can be a bit like sunburn (redness, blotchy and itching) in children with pale skin, and darkening of the skin in those who have darker skin.

As your child’s skin will be more sensitive after radiotherapy, you should take care to protect them from strong winds and the sun and always ensure they wear a sunhat with neck protection when they are outside.

Usually, the sensitivity will fade in the month or so after treatment.

This is because radiotherapy increases the risk of developing skin cancer. Your child’s health team will be able to give you further guidance if your child develops skin sensitivity.

Your child should continue to use a high-factor sunscreen on areas of skin that have received radiotherapy in the long-term.

If your child has radiotherapy, particularly targeted at the lower part of their brain, they may feel nauseous or actually be sick following treatment. This can start from around an hour after treatment and last some weeks. 

Your child’s doctor can give them anti-sickness tablets (known as anti-emetics) to help manage this. They may be able to refer you to a dietitian or suggest other tips to help your child eat when they are feeling sick.

As a result of fatigue, feeling sick or actually vomiting after radiotherapy, your child may temporarily lose their appetite. 

If this happens, meal supplement drinks may be a good alternative, but always speak to your child’s health team first, as some drinks could affect their treatment. They may also have other tips for helping your child to eat.

Radiotherapy can temporarily slow the production of the various types of blood cells by the bone marrow, which medical experts call myelosuppression.

This can lead to anaemia, increased risk of infection and/or bleeding, such as bruising or nosebleeds.

If your child has had radiotherapy to the brain and spine, or if they are also having chemotherapy, they are more at risk of these effects. Some children may need a blood transfusion to correct these effects.

Will there be any long-term side-effects of radiotherapy for children?

Unfortunately, because a child’s central nervous system is still developing, radiotherapy treatment can cause some long-term effects. These can be initial side-effects that remain permanently e.g. hair loss. Or they can appear, or become more pronounced, in later years. Health professionals call these as ‘late effects’.

The nature of these late effects depends on various factors. These include where in the brain your child has received radiotherapy and which other parts of the brain are included in the radiotherapy treatment area.

Your child’s health team will talk through any side-effects with you and, if appropriate, your child before receiving any treatment. Long-term effects of radiotherapy could include impacts on:

‘Cognitive skills’ include thinking, memory, learning, concentration, decision-making and planning. They also include ‘processing skills’ – recognising and making sense of information from your senses, particularly sight and hearing.

If your child has had radiotherapy to a large area of their brain, they should have a neurological assessment to identify specific learning or processing difficulties.

These types of difficulties can vary greatly from child to child. They can depend, to some extent, on how old your child was when they received treatment and the intensity of their treatment.

Cognitive difficulties are often subtle and can take longer to diagnose and support.

Emotional difficulties can be wide-ranging. Your child may:

  • show heightened emotions
  • have difficulty controlling anger
  • be impulsive
  • take excessive risks without fully understanding the danger.

Emotional difficulties can arise from anxiety, for example if your child is worrying that the tumour may return. They can also arise from anger (at having had to go through treatment when other children they know have not).

They can also arise due to physical changes to the area of the brain which controls emotions and inhibitions.

If you’re worried that your child is showing concerning behaviour, you may wish to find psychological support. This could also be done as a preventative measure involving all family members. This could help your family cope with such emotions, if and when they arise.

If your child has radiotherapy directed at the pituitary gland at the base of the brain, it is possible that they may grow more slowly or start growing later than their friends. This is because the pituitary gland controls the hormones that are linked to growth and development. And radiotherapy to the gland can mean that not enough of the growth hormone is made. However, an artificial version of the growth hormone can be given to your child to counteract. This effect as your child gets older.

The effect of radiotherapy on the pituitary gland and the hormones it controls may disrupt puberty. As a result, your child may start puberty earlier or later than usual. Girls, in particular, who have had radiotherapy to the head, are more likely to begin puberty earlier. Medicines can be given to halt puberty if your child starts earlier than usual. Or to bring on puberty if it has been delayed.

Growth can also be affected if radiotherapy is given to the spine. This is because radiotherapy can affect growing bones, such as the vertebrae in the spine. To prevent curvature of the spine, such as a hunch or stoop, any vertebra needing radiotherapy will receive radiation to the whole vertebra to stop it growing unevenly.

Other possible long-term side effects of radiotherapy for children

  • Cataracts – if your child receives radiotherapy near their eyes, there is a chance that they could develop a cataract several months or even years later. Cataracts can cause impaired vision, for example, blurring or cloudiness. However, they can easily have treatment with a simple operation.
  • Heart conditions – if radiotherapy is given to the spine as well as the brain, there is a slightly increased risk of developing heart conditions later in life as some radiation will enter the chest area.
  • Second tumour – there is a slightly higher risk of later developing a second (different) tumour in the area of the brain where your child received the radiotherapy.

Radiotherapy (children) – PDF

Download our information about radiotherapy for children in a printable format.

Radiotherapy (children) – Clear Print – PDF

Download our information about radiotherapy for children in a printable, Clear Print format.

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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