Radiotherapy of the pituitary area for children
This information has been produced to provide details about radiotherapy of the pituitary area for children in Newcastle, and aims to answer some of the questions often asked by patients and their carers.
We hope you will find this helpful.
The pituitaryis a small but very important gland producing hormones that control growth and other functions of the body. It lies in the middle of the head behind the eyes where the large nerves of the eyes can be squashed and damaged by tumours (swellings).
Several different types of tumour occur in this area though none of them are common. Gliomas, optic nerve gliomas and germ cell tumours are the most usual. Craniopharyngiomas also occur here, these are benign but if they grow unchecked can do a lot of damage.
We give radiation treatment (radiotherapy) after surgery because the disease is likely to come back if we do not. The treatment has to be planned with great care and it is successful for many but unfortunately not all patients.
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 about five or six weeks (usually excluding weekends and bank holidays). At each session, the patient spends about ten minutes in the treatment room but most of this time is spent getting the patient into the correct treatment 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 area accurately, which means that the patient must lie very still on their back. To make this easier, we make a facemask for each patient. Lying still can be very difficult for some children, particularly young ones, so occasionally we have to use a general anaesthetic.
Occasionally when we are treating the brain, some patients experience a strange smell. This does not happen for everyone. Also a buzzing noise can be heard which is the machine working.
There are always side effects to radiotherapy. 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
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 relieving it with a shunt (a pressure relieving device). If swelling causes problems we give a small dose of steroids.
Pressure on the eye nerves can occasionally occur during this treatment. It is important to report any changes in vision during treatment so we can carry out any appropriate tests.
We cannot prevent patients losing their hair in the area being treated. It starts to fall out after about two weeks of treatment and is more or less gone by the end. It usually starts to grow back about three months after treatment though it might be a little thinner than before treatment.
Nausea and vomiting are uncommon with this treatment.
Side effects after treatment
A long course of radiotherapy can make the patient 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 prescribed to relieve this.
These side effects can be very worrying at the time but they usually all settle down within two or three months.
Long-term side effects
These are the hardest to predict and unfortunately, when they do happen, they are permanent.
Young children will not grow to be as tall as they would have been. The pituitary gland may be damaged by the tumour or the radiation so that it does not produce growth hormone. Growth hormone injections can 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 and advise on the replacement of hormones normally produced by the pituitary.
It is possible for radiotherapy to affect learning ability. Research indicates that by three or four years after treatment young children don’t learn new information and skills quite as easily. We are hopeful that treatment limited to the pituitary area will not significantly affect brain development. One of our neuro-psychologists may see the patient early in treatment and yearly afterwards.
Pressure on the optic (eye) nerves by the tumour might have caused some permanent damage to the sight. Both surgery and radiotherapy can, very occasionally, add to this damage.
We are finding that, very rarely, children who have had treatment for one tumour can develop another type of tumour some years later.
Your oncologist will explain this during the consent process. During follow-up we will be looking out for all these problems.
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