Radiotherapy treats cancer cells by using high-energy rays to destroy the cancer cells while doing as little harm as possible to normal cells. It is usually given using beams delivered from outside the body (external radiotherapy).

Radiotherapy is often used after surgery to treat any cancer cells that may have been left behind. It can also be given to treat secondary brain tumours, or when a primary brain tumour can’t be removed or has come back after surgery. Radiotherapy may sometimes be given in combination with chemotherapy tablets to treat high-grade gliomas.

Radiotherapy is given in the hospital radiotherapy department. It is usually given as a series of short, daily sessions from Monday to Friday, with a rest at the weekend. The number of weeks your treatment lasts will depend on the type and size of brain tumour, but is usually 2–6 weeks. Some people will have different treatment plans and may have treatment on only three days a week. Your doctor will discuss your treatment with you beforehand.

You may need to wear a see-through perspex device called a mould or mask to keep your head as still as possible during treatment. This is to make sure that exactly the right area is treated. Your mould will be made before your treatment is planned. It allows you to see and breathe normally but it may make some people feel claustrophobic. You will only have it on for a few minutes at a time and most people soon get used to it.

For secondary brain tumours and some high-grade tumours, a smaller dose of radiotherapy is given to the whole head, so a mould may not be needed.

To ensure that you receive maximum benefit from your radiotherapy, it has to be carefully planned. This is done using a CT scanner or a similar machine called a simulator, which takes x-rays of the area to be treated. Treatment planning is a very important part of radiotherapy and it may take a few visits before the clinical oncologist (the doctor who plans and supervises your treatment) is satisfied with the result.

Before each session of radiotherapy the radiographer, who gives you your treatment, will position you carefully on the couch and make sure you are comfortable. During your treatment, which will only take a few minutes, you will be left alone in the room but you will be able to talk to the radiographer, who will be watching you carefully from the next room. Radiotherapy is not painful but you do have to be still for a few minutes while it is being given.

Stereotactic radiotherapy or radiosurgery

These types of radiotherapy enable doctors to direct radiation more accurately at brain tumours. The aim is to deliver higher doses of radiotherapy to the tumour while doing as little harm as possible to surrounding brain tissue and to minimise the side effects of treatment. It is sometimes given after standard external radiotherapy or to treat small tumours that cannot be removed with surgery.

Stereotactic radiotherapy This type of radiotherapy gives the treatment from a standard radiotherapy machine which has been adapted. The machine gives concentrated beams of radiation from several different angles which overlap at the brain tumour. This is done either by moving the machine during treatment or by aiming individual beams from a number of different directions. You need to wear a special frame fitted to your head to keep it still.

The radiotherapy dose to the tumour is very high and the dose to surrounding healthy tissues is very low. Several doses are given. Before the treatment is carried out, several scans will be analysed by computers to target the radiotherapy precisely. This treatment is only available in specialist hospitals and is not suitable for everyone with a brain tumour. It could be helpful to discuss with your clinical oncologist whether it would be appropriate in your particular case.

Stereotactic radiosurgery (gamma knife) does not use a knife, but uses very highly targeted beams of gamma radiotherapy given from hundreds of different angles, which cross at the point of the tumour. Only one session of radiotherapy is needed, which takes about 4–5 hours. In order to have the treatment you will have a specially-made metal frame attached to your head. You will then have several scans and x-rays to find the precise area for the treatment to be given. To have the treatment you lie with your head in a large helmet, which has hundreds of small holes in it to allow the radiotherapy beams through.

The type of radiotherapy beam used for this treatment is gamma radiation. This is why it is often called the gamma knife. Again, this treatment is only available in specialist hospitals and is not suitable for everyone with a brain tumour. It may be helpful to discuss with your clinical oncologist whether it could be appropriate for you.

Side effects can be mild or more troublesome depending on the amount of radiotherapy given and the length of your treatment. Radiotherapy can cause general side effects such as tiredness, headaches, hair loss and feeling sick (nausea).

Tiredness

As radiotherapy often makes you feel tired, try to get as much rest as you can, especially if you have to travel a long way for treatment each day.

Headaches

Some people have headaches while they are having their radiotherapy. These can be controlled with painkillers prescribed by your doctors.

Hair loss

You will lose any hair within the treatment area. Most hair loss is temporary although, unfortunately, in some people it may be permanent. This will depend on the dose and length of treatment you have had. Sometimes hair grows back with a slightly different colour and texture, and perhaps not as thickly as before. It usually starts to grow back within 2–3 months of finishing treatment.

Skin changes

Some people develop a skin reaction, similar to sunburn, while having radiotherapy. This normally happens 3–4 weeks after the start of your treatment. People with pale skin may find that the skin in the treatment area becomes red and sore or itchy. People with darker skin may find that their skin becomes darker and can have a blue or black tinge. The amount of the reaction depends on the area being treated and the individual person’s skin. Some people have no skin problems at all. Your radiographers will be looking for these reactions but you should also let them know if you feel any soreness.

Staff at the radiotherapy department will be able to give you advice on skin care. As the skin is sensitive it is best not to over-expose it to the sun or cold winds. Try wearing a soft cotton or silk scarf or hat to cover the area when you go outside.

Somnolence (feeling drowsy)

This side effect occurs 6–12 weeks after radiotherapy. You may find that you generally slow down, have very little energy and cannot be bothered to do much. It gradually gets better over a few weeks.

Feeling sick

Occasionally some people may feel sick (nauseated) but this can usually be effectively treated by anti-sickness drugs (called anti-emetics), which your doctor can prescribe. You may also find that food tastes different. If you don’t feel like eating, you can replace meals with nutritious, high-calorie drinks. These are available from most chemists and can also be prescribed by your GP.

Some people find the symptoms of the brain tumour temporarily get worse after the treatment has finished. This can make them think their tumour is getting worse, but in fact it is a reaction to the radiotherapy treatment. If you find this happening to you it is important to discuss it with your doctor or nurse, who will be able to provide the right treatment and support.