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Stereotactic Radiosurgery (SRS) for benign brain conditions

This leaflet tells you about a type of radiotherapy treatment called stereotactic radiosurgery. The leaflet will explain how your treatment is planned and given. It will discuss side effects you may have and will tell you how to get more information and support. Contact telephone numbers are given at the end of the leaflet.

We hope this leaflet answers your questions.  Please ask us if you have other questions that we have not covered.

A glossary is provided at the front of this booklet to help you understand any words that you may find unfamiliar.  

Please bring a list of all the medication you are taking with the doses when you come for your radiotherapy treatment.

Information on how to get to Velindre Hospital is at the back of this leaflet.
Smoking is not allowed within the grounds and inside Velindre Hospital. If you need help giving up please ask us.

This information is evidence based and reviewed annually

Glossary of terms

CT Scanner - a machine that uses X-Rays to take detailed scans of your body 

MRI Scanner - a machine that uses magnetism to take detailed pictures of your body

Treatment field -    Each area that the treatment machine points to on your mask is called a treatment field.

LA - This is the radiotherapy treatment machine where you will have your treatment (also called a linear accelerator or Linac). You may be treated on LA2 or LA4

Oncologist – a doctor who specialises in giving radiotherapy treatment.

Review Radiographer – a radiographer who has undergone extra training to help you cope with radiotherapy side effects and can prescribe medication for you.

What is stereotactic radiosurgery (SRS)?

It is a very precise type of radiotherapy treatment which is given to a small area of the brain. All of the radiotherapy is given in one fraction or treatment. We give it this way because it reduces the effect of the radiation on your normal brain tissue. It also helps to reduce the risk of late side effects.
To make sure that you are in exactly the same position for each treatment, you will need to wear a special treatment mask (shell). Most patients find the treatment shell quite comfortable to wear during their treatment sessions. 

It is very important that you are not pregnant when you have radiotherapy as even small amounts of radiation can be harmful to a developing foetus.
Three planning visits are usually needed before you start treatment.

The first planning visit - MRI scan

You may need to have an MRI scan. This will be done before you have your mask made. It will help us plan your treatment.  

The second planning visit - making your mask

The mask used for your treatment is made in the mould room. The mould room is part of the planning department for radiotherapy treatment. It is situated near out-patients, at the front of Velindre hospital.

It would be helpful if you could have your hair trimmed before coming to the mould room. This will help us get a good fit with the treatment mask.

What is a treatment mask?

The treatment mask is a plastic mask that you will wear each day when you have your radiotherapy treatment. It will cover your whole head down to your chin. 

Radiotherapy mask for head and neck treatment
Patient in a treatment mask

How is the mask made?

We will use warm plastic (not hot) to take an impression of the back of your head and then the front of your head, from your forehead to your chin. The plastic sheet is full of small holes, so you will be able to breathe normally through your nose and mouth. 

The plastic is warm as it goes on and it will be allowed to cool. This is not uncomfortable and most people find it quite soothing.

How long will it take?

It takes about 45 minutes to make the impression, but please allow an hour for your whole appointment.

The third planning visit – CT scan

At this appointment you try on your plastic mask. Then you will need a CT planning scan wearing your mask. 

On one of your visits to the mould room or planning, we will ask you to sign a treatment consent form. Your doctor will explain this to you. Please ask any questions or discuss any worries that you may have.

When will I start treatment?

Treatment normally starts about two to four weeks after these planning visits.  If you have any questions before coming to see us, please phone the mould room on 029 2031 6213 and you will be able to speak to a member of the mould room staff.


Your treatment will be given on a machine called a linear accelerator or LA.
Your radiographers will fit your treatment mask and they will make sure you are as comfortable as possible. They will move the machine so it is in exactly the right place for your treatment using the room lasers and lights.

Head and Neck patient on treatment couch
Patient being positioned for treatment

Your radiographers leave the room to switch the machine on. The treatment is given from several directions.  Each direction is called a ‘field’ or “beam” and the whole treatment will take between 30 and 45 minutes to give. Your radiographers watch you carefully on television monitors. If you have any problems during the treatment, the machine can be switched off at any time.

You will not feel anything when you are having your treatment, though you may hear the machine buzzing or beeping.

Truebeam treatment machine
Picture of Linear Accelerator Treatment Machine

Side effects

We do not expect you to have many side effects because the treatment beams are targeted very precisely. However, you may feel tired and possibly lose some hair in the treated area. You may also experience some nausea or sickness and develop a headache. You will be seen by one of the Review Radiographers. They will be able to advise you about coping with any side effects. You may need a course of steroid tablets during your radiotherapy. These will be prescribed for you if necessary.

Follow up

One of the Review Radiographers will give you a follow up telephone call about 1 week after your radiotherapy treatment and another call 6 weeks after treatment. You will also have a follow up appointment with the doctor who referred you for radiotherapy treatment. This may not be for a few months. If you have any problems or concerns following your radiotherapy treatment please contact the Review Radiographers. Their number is at the back of this booklet.

Contact phone numbers

Mould Room Radiographers 029 2031 6213

Review Radiographers Mon-Fri 8.30am – 5pm 029 2061 5888 ext 6421

Research Radiographers 029 2061 5888 ext 6262

Treatment Superintendent Radiographers 029 2061 5888 ext 6367

Transport from Aberdare    
Cancer Support Cynon Valley
 01443 479369
Transport from Bridgend
01656 743344

Transport from Merthyr 01685 379633
Cancer Aid Merthyr     
Transport from Rhondda Cynon Taff
Community Cancer Services
01443 421999

Helplines and websites

Tenovus cancer support line 0808 808 1010
A charity supporting people with cancer and their families

Macmillan cancer support 0808 808 0000        
A charity providing information about all aspects of cancer

Stop Smoking Wales  0800 085 2219
FS  37622

F.PI 43                                    Issue 1                      March 2015