Radiotherapy of the whole nervous system 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.
Treatment of the brain and spine together is used to treat germ cell tumours and some other types of brain tumour. In most cases the treatment is successful but unfortunately not in all. The total radiation dose has to be spread out over quite a long time to make the individual treatments safe.
We give treatment every day for up to seven weeks (usually excluding weekends and bank holidays). At each session, the patient spends about twenty minutes in the treatment room but most of this time is spent getting him/her into exactly the right position.
Radiotherapy does not hurt; the machine does not touch the patient and it is rather like having an ordinary x-ray. We have to treat the whole brain and the spine. This means that patient must lie very still on their front. To make this easier, we make a facemask for each patient. Lying still can be very difficult for some children, especially very young ones. Sometimes we have to use a general anaesthetic.
Occasionally 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.
We treat the whole brain and spine in the first 16 - 20 sessions. After that, we give extra treatment to the place where the tumour was found originally. If a scan shows that the disease has spread to anywhere else in the brain or spine, we give extra treatment to those places as well.
There are always side effects. 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.
Sometimes the treatment causes the brain to swell slightly (at its greatest about ten days into treatment). This is usually not noticeable because pressure on the brain has been eased by removing the tumour or by relieving it with a shunt (a pressure relieving device). If swelling causes problems, we give a small dose of steroids.
We cannot prevent patients losing their hair. It starts to fall out after about two weeks of treatment and is more or less all gone by the end. It usually starts to grow back about three months after treatment. Hair might not grow back fully in the areas that have had a high dose of radiation.
A sore throat can be a problem, starting about three weeks after treatment begins. Medication can be given to help.
Some patients feel sick and vomit because part of the radiation on the back passes on through their stomach. When this happens, we can control the problem with anti-sickness drugs
Side-effects after treatment
A long course of radiotherapy makes patients very tired. This is most noticeable near the end of the treatment and just afterwards. There might be a particularly sleepy spell starting four to six weeks after treatment ends and going on for two to six weeks or even longer.
There may be occasional headaches or bouts of sickness. Medication can be given to help.
These side effects can be very worrying at the time but usually they all settle down within 6 - 12 months.
Long-term side effects
These are the hardest to predict and, unfortunately, when they do happen they are permanent.
Young children will not be as tall as they would have been. The radiation affects the gland that controls growth (the pituitary gland). Also, radiation affects the bones of the spine (the vertebrae) and they do not grow, as they would have done. Growth hormone can improve things. However, a young child may be up to several inches shorter when grown-up than without the illness and the treatment.
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; they will also monitor the thyroid gland as this can also be affected by radiotherapy.
Girls' fertility is occasionally affected due to the effect of radiation on their ovaries. Options for overcoming infertility can be discussed at the appropriate time. Boys are not affected because their testicles are well away from the treatment area.
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. When it is possible, one of our neuropsychologists will see the patient before treatment starts and yearly afterwards.
Development of cataracts. This may occur 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.
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