Stereotactic radiotherapy for brain tumours

Stereotactic radiotherapy is a way of targeting radiotherapy very precisely at the tumour. You have the treatment aimed at the tumour from many different points around your head. This type of treatment is not available at all hospitals because it needs specialist equipment and skills.

The radiotherapy beam is targeted very accurately with this type of treatment. So it is vitally important that your head is in exactly the same position each time and does not move while you are being treated.

You have the treatment with a linear accelerator (LINAC). This is the same type of radiotherapy machine used for regular external beam radiotherapy. Stereotactic radiotherapy treatment is usually divided into between 6 and 25 daily doses called fractions. A single fraction of stereotactic radiotherapy is called radiosurgery.

This type of treatment can be used for

• Secondary brain tumours
• Gliomas that have come back since they were first treated

It is also used for a number of benign (non cancerous) brain tumours such as

• Acoustic neuromas
• Meningiomas growing in the base of the skull
• Pituitary adenomas
• Chordomas

You can't have this type of treatment as your main treatment for high grade brain tumours. High grade tumours tend to send finger like growths into the normal brain tissue. This would mean that you would need to have too large an area of the brain treated.

To have stereotactic radiotherapy you need to have a head frame made. This can take up to a week to do and must be very accurate. The frame is made very carefully and specifically for you using the information from your scans.

Another way of fixing the frame is to have a thermoplastic mask made. The frame fixes to the mask. The mask in turn attaches to the scanner or radiotherapy machine bed while you are wearing it. This means you cannot move, but there is nothing actually attached to you directly.

Stereotactic radiotherapy planning is similar to having planning for normal external radiotherapy. The specialist uses a CT scanner or MRI scanner. You have to wear your mask and head frame while your treatment is being planned.

During planning, your specialist uses the scans to work out how to shape the radiotherapy beam so that it exactly fits your tumour. This means that the normal brain tissue surrounding the tumour gets a very low dose of radiation. So you will have fewer side effects than with conventional radiotherapy.

The planning session is the most important part of your treatment. Your specialist has to do this very carefully and precisely and it can take up to 2 ½ hours.

You go to the hospital a number of times to have treatment. The treatment itself does not take very long. But it takes a little while for the radiographer to fit the mask and head frame and position you on the radiotherapy table. You can go home as soon as each treatment is over.

Stereotactic radiotherapy treatment has fewer side effects than the usual type of radiotherapy. This is because less healthy brain tissue is exposed to radiation. You will not normally have hair loss, feel sick, or have any reddening of your skin. All these are common side effects of regular external beam radiotherapy to the brain. But you may feel very tired for a while afterwards.