What is stereotactic radiosurgery (SRS)?

Brain tumours can be treated with different types of radiotherapy.

Stereotactic radiotherapy (SRT) is a way of accurately focusing external beam radiotherapy. It uses many small, thin radiotherapy beams given from different angles. They cross over at the tumour. This means the tumour receives the full dose of treatment. But nearby areas are only affected by the individual low-dose beams. This lowers the risk of damage to normal cells and can reduce possible side effects. Stereotactic radiosurgery does not involve any surgery.

Sometimes SRT can be used to give radiotherapy as a single high dose treatment. This is called stereotactic radiosurgery (SRS). If the dose of radiation is too high to be given as one treatment, it can be split into more treatments.

SRS is not a suitable treatment for everyone with a brain tumour. It depends on:

  • the type of tumour
  • the size of the tumour
  • the number of tumours in the brain
  • where the tumour is in the brain.

SRS can be used to treat some types of benign primary brain tumours such as:

It can also sometimes be used to treat brain metastases (secondary brain tumours).

Radiotherapy machines for SRT

There are different types of radiotherapy machine. The most commonly used machine for standard external beam radiotherapy is called a linear accelerator (LINAC). SRT can also be given using a LINAC. But it may be given using a machine that is only used for SRT, such as a Gamma Knife™ or CyberKnife™ machine.

SRT is not available at every hospital. You may have to travel to have this treatment. You may be able to get help with travel costs.

Planning SRS treatment for brain tumours

Before you have SRS, it needs to be planned. This is an important part of your treatment. Planning makes sure the radiotherapy is aimed precisely at the tumour and causes the least possible damage to nearby areas of the brain.

Your treatment may be planned on the same day as it is given or at an earlier appointment. This depends on the type of radiotherapy machine or system being used. Your radiotherapy team will tell you what to expect.

Masks and headframes

Masks are usually made from plastic mesh that is moulded to fit the shape of your face. You may have a mask made on the same day that your treatment is planned or at an earlier appointment.

For your treatment, you lie on a treatment couch. The mask is gently placed over your face and fixed to the couch. The mask should be tight but not uncomfortable. You can breathe normally while you are wearing it.

We have more information about how radiotherapy masks are made.


For some types of SRT, you wear a light-weight metal head frame. The frame sits around your head and stays firmly in place by pressing against your skull at four points. This sounds scary and it may be a bit uncomfortable, but it should not be painful.

Head frames are usually fitted on the same day that you have SRT.

You have local anaesthetic to numb the four points where the frame will push into your skin. Your team gently position the frame around your head.

Some types can be fitted then taken off until your treatment session. Others are fixed. This means you wear the frame all day until your treatment session is over. You can move around with it on and can eat and drink normally. But you may find it helpful to wear shirts that button or zip up, because it can be difficult to take clothes off over your head.

For your treatment, the frame is fixed to the treatment couch. At the end of your treatment session your team gently remove the frame from your head. The frame will leave four tiny wounds on your skin. These usually heal in a few days. Your radiotherapy team will give you information about how to care for these small wounds. If the wounds feel sore, ask them about painkillers.

You may feel very nervous about wearing a mask or head frame. You may want to bring some calming music or a relaxation podcast to listen to during your treatment. Most people cope well with the support of the radiotherapy team. If you are worried or uncomfortable, tell them, so they can help you.

Scans and planning

Before you have your treatment, you have a brain CT or brain MRI scan or both. Your radiotherapy team uses information from the scans to plan your treatment.

The radiotherapy team help you get into position for the scan. You lie on a treatment couch in the same position you will be in for treatment. The mask or head frame is gently fixed to the couch so your head and neck do not move during the scan. If you are uncomfortable, tell the staff. They may be able to adjust the mask or frame slightly or help you move into a more comfortable position.

During the scan you may be alone in the room. Your radiotherapy team can see, hear and talk to you and are close by if you need them at any time.

Before your treatment

Your radiotherapy team will talk to you about any medications you take. It is important to tell them if you have any allergies. If you take painkillers, they may suggest you take them before your treatment so that you are comfortable.

Radiotherapy can cause some swelling of the area being treated. This can cause side effects or make any symptoms of the brain tumour worse for a time. Your doctor may give you steroids to take before your treatment to help this. You will usually keep taking them for a time after treatment. Follow your doctor’s instructions carefully and do not stop taking the steroids without your doctor’s advice.

Having SRS treatment for brain tumours

For your SRS treatment, you lie in the same position as you did for the planning scans. The radiotherapy team will help you get comfortable and will fix the mask or head frame to the treatment couch.

The treatment itself is not painful. You may hear a slight buzzing noise from the radiotherapy machine during treatment. Depending on the type of radiotherapy machine, there may be equipment that moves around you during the treatment. The couch you lie on may change position slightly during treatment.

In some treatment rooms you can listen to music to help you relax. If you would like to listen to your own music, ask your radiotherapy team if this is possible.

You may only need one session of treatment. Or it may be broken up with short breaks or spread over several days. A session of treatment can take from about 15 minutes up to 4 or more hours. This depends on the type of machine and the number of tumours being treated. Your radiotherapy team will tell you what to expect. Tell them if you are worried about any part of having treatment. They will try to make things as comfortable as possible for you.

The team will not be in the same room with you when you have the treatment. But they can see, hear and talk to you, and will be close by if you need them at any time. You can usually go home when the treatment is finished.

SRS does not make you radioactive. It is safe for you to be with other people, including children, after your treatment.

Side effects of SRS for brain tumours

Side effects can depend on which area of the brain has been treated and the dose of radiation given. Your doctor will explain the likely side effects of your treatment. Some side effects are mild and easy to cope with. Others may be managed with drugs or other treatments.

We have more information about side effects after radiotherapy for a brain tumour. You may develop some of the side effects mentioned. You are unlikely to have them all.

Side effects usually get better gradually after your treatment. Sometimes side effects or symptoms of the brain tumour get worse for a while after treatment has finished. If this happens, you may feel upset or worry that treatment is not working. But this is usually a normal reaction to the radiotherapy. It may also happen because your steroids have been reduced or stopped.

Tell your radiotherapy team about any side effects. They may give you drugs to help and practical advice about managing side effects.

Driving and SRS for brain tumours

Most people diagnosed with a brain tumour will not be allowed to drive for a time after their diagnosis.

Most people diagnosed with a brain tumour will not be allowed to drive for a time after their diagnosis. Your doctor, surgeon or specialist nurse will tell you if this applies to you. This change can be upsetting and frustrating. But you must follow the advice they give you.

If you have a driving licence, you must tell the licencing agency that you have been diagnosed with a brain tumour.

If you live in England, Scotland or Wales contact the Drivers and Vehicle Licensing Agency (DVLA). If you live in Northern Ireland, contact the Driver and Vehicle Agency (DVA).

You could be fined if you do not tell them that you have been diagnosed with a brain tumour. You could also be prosecuted if you have an accident.

If you have to stop driving, the DVLA or DVA will tell you if and when you are allowed to start driving again. This depends on:

  • the type and grade of your tumour
  • whether you have had any seizures
  • what treatment you are having
  • the type of driving license you have.

They may ask you if they can get medical information about you from your doctor.

After SRS for brain tumours

After treatment, you will have regular check-ups with your doctor and nurse. Sometimes SRS causes side effects that develop months or even years later. These are called late effects.

Your radiotherapy team will explain your risk of these before you agree (consent) to have SRS. You can use your follow-up appointments to talk to your doctor about any side effects, or other worries you have.

Date reviewed

Reviewed: 01 October 2019
Next review: 01 October 2021

This content is currently being reviewed. New information will be coming soon.

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