Northern Centre for Cancer Care

Radiotherapy of the whole brain for leukaemia for children

This page has been written to give you general information and answer some of the questions you may have about the side effects of radiotherapy.

We hope you will find this helpful.


When the spinal fluid obtained at lumbar puncture contains some leukaemia cells, radiation treatment (radiotherapy) to the brain is recommended. The total radiation dose has to be spread out over quite a long time to make the individual treatments safe. We give 15 treatments, one every day (usually excluding weekends and bank holidays). At each session, the patient spends about ten minutes in the treatment room. Most of this time is spent getting him/her into exactly the right position.

Radiotherapy does not hurt; it is rather like having an ordinary x-ray. So that we can treat the whole brain the patient must lie very still. To make this easier, we make a facemask for each patient. Lying still can be very difficult for some children, especially very young ones. Occasionally we have to use a general anaesthetic.

Sometimes when we are treating the brain, a blue light is seen and there might be a strange smell. Also a buzzing noise can be heard which is the machine working.

Side effects

The dose of radiotherapy to control leukaemia is relatively small which means that side effects are usually mild. We can relieve most of them but sometimes not completely. Some of the side effects happen immediately, some of them happen soon after we finish treatment, and some take a longer time to show.

Immediate side effects 

  • Very occasionally the treatment causes the brain to swell slightly (at its greatest about ten days into treatment). If swelling causes problems, we give a small dose of steroids.
  • The hair has usually been lost as a result of chemotherapy but if not it will start to fall out about two or three weeks after the start of treatment. It starts to grow back about three months after all the radiotherapy and chemotherapy causing hair loss is finished.
  • Sickness is unusual during this treatment.

Side effects after completing treatment

  • A sleepy spell is often experienced starting about six weeks after treatment ends and going on for about two weeks, sometimes even longer. It gets better without any treatment usually.

Long-term side effects

  • These are the hardest to predict and, unfortunately, when they do happen they are permanent.
  • Radiation may affect the gland that controls growth (the pituitary gland). It is unusual for this treatment to affect growth and require treatment. However, if growth is reduced, growth hormone can be given to improve things. The pituitary gland also controls development. Radiotherapy for children may make puberty start earlier. Endocrinologists (doctors specialising in hormones) will help deal with any problems.
  • The ovaries and testicles are well away from the treatment area so future fertility will not be affected by this treatment.
  • It is possible for radiotherapy to affect learning ability, especially when very young children’s brains are treated. We are finding that by three or four years after treatment young children don’t learn new information and skills quite as easily. We need to know exactly what the effects are and how we can support and help people who have been affected. Sometimes a neuropsychologist will be involved in follow up. It is important to remember that children who have had this treatment still go on to higher education.
  • Cataracts may develop because of unavoidable radiation to the eye. Fortunately cataract surgery today is very straightforward and successful 
  • We are finding that, very rarely, children who have had treatment for one tumour can develop another type of tumour some years later.

During follow up we will be looking out for all these problems.

More information

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