This guide is designed to give patients and their doctors an overview of Cyberknife radiosurgery and to answer practical questions about the treatment.

Note: for more detailed information, please refer to our specialist Cyberknife website at www.cyberknifeservice.com.

This guide covers:

What is Cyberknife radiosurgery?
Cyberknife technology
What are the advantages?
What is it like?
Where is it available?
What do I do next?

Please note: As with any possible treatment, you should make any decision about Cyberknife radiosurgery in full consultation with your GP or specialist.

For further information for doctors, including a Letter to Doctors and an Enquiry Form, please return to the main cyberknife page on this site and use the Medical Professionals button on the page.

What is Cyberknife radiosurgery?

CyberKnife® radiosurgery is a precise, painless, non-invasive radiation treatment that can be an alternative to open surgery or conventional radiotherapy in certain cases. It uses very fine, high power radiation beams instead of a scalpel, so there is no incision, no blood and no pain.

It is used for certain forms of cancer and conditions such as acoustic neuroma, trigeminal neuralgia and AVMs (arteriovenous malformations) where high precision is required to avoid damage to adjacent nerves and blood vessels.

CyberKnife® uses a miniature linear accelerator mounted upon a highly flexible, robotically controlled arm to deliver fine beams of radiation. These are fired from many different angles so as to focus precisely on the tumour, AVM or other target.

Each individual beam is insufficient to cause harm, but the convergence of all the beams means that the target receives a very high dose of radiation whilst sparing nearby normal tissue much more effectively than radiotherapy can.
CyberKnife® radiosurgery is so precise that radiation beams can be sculpted to small, complex-shaped tumours near critical structures, such as hearing and vision nerves, where surgeons will not conduct open surgery.

Whilst it is a major breakthrough for a wide range of conditions, media headlines of 'miracle cures' of celebrities can over-simplify and raise unreaslistic hopes. In fact CyberKnife® is not a single fixed procedure but an operational tool. Each surgeon brings his own unique experience to it so different centres have their own approaches and CyberKnife® may form only part of a wider treatment.

Radiosurgery v Radiotherapy

Radiosurgery differs from conventional radiotherapy in several important respects.

Radiotherapy depends primarily on tumour cells having greater sensitivity to radiation than normal tissue. To protect normal tissue as far as possible the treatment is fractionated over many sessions, usually over a period of several weeks.

Radiosurgery does not remove the tumour but destroys tumour cells or stops growth of active tissue. The main forms of radiosurgery available today are Linac (linear accelerator), GammaKnife® and CyberKnife®, of which CyberKnife® is the most recent and the most flexible.

Cyberknife was licensed for use by the United States Food and Drug Administration (FDA) in 1999 for brain and spine and then whole body in 2000.

To date, approximately 50,000 plus worldwide people have been treated with Cyberknife.

Currently, there are 21 Cyberknife treatment centres in North and South America, 15 in Europe, 21 in Japan and a further 21 in the rest of Asia.

Is Cyberknife clinically proven? The CyberKnife® system is based on radiation technology that has been proven for 30 years and in 2001 it received FDA (the US medical regulatory body) clearance for treatment of tumours anywhere in the body where radiation was indicated.

Many clinical studies have been published in medical journals, over 50,000 patients have received treatment and there are now 150 CyberKnife® systems installed worldwide. Several centres have now installed a second CyberKnife® to cope with rising demand.

I read somewhere that CyberKnife® is 'experimental'? Because CyberKnife® is not yet available in some countries or is still new there, some doctors and medical charities are not yet familiar with it or are unaware of how well established CyberKnife® has become in the rest of the world.

As with any new medical technology, CyberKnife® had to pass through a phase when treatments were regarded as 'experimental'. The different organs of the body also require their own special treatment protocols, so as these are developed there is necessarily an 'experimental' element in each case.

Cyberknife technology

This section gives an overview of the technology behind the Cyberknife stereotactic radiosurgery system. This section covers the Cyberknife:

• image guidance system
• precision robotics, and
• radiation device.
  
  

Image guidance system The computer-assisted image guidance system tracks the location of the tumour throughout the treatment, making adjustments as the patient moves or breathes.

This means that there is no need for the patient to be immobilised in a frame, as is usual with other radiosurgery treatments. The patient can lie free on the treatment couch whilst the CyberKnife moves from one position to the next.

Precision robotics The Cyberknife system has a highly flexible robotic arm which can reach tumours anywhere in the body. This allows it to treat areas that other radiosurgery systems cannot reach and to offer a more flexible delivery of radiation.

Radiation device This is a lightweight 6MV linear accelerator with a dose rate of 6Gy/min, mounted on the robotic arm. It works by delivering individually harmless fine radiation beams from multiple sites, which converge at the precise site of the tumour.

This allows the tumour or lesion to receive a dose of radiation high enough to damage its DNA and so destroy its cells, without harming the healthy cells around it.

What are the advantages?

100% Frameless

The ability to correct for patient movement during treatment avoids the pain and inconvenience of a conventional head frame, that must be fixed to the skull with screws. Published studies have shown that frameless CyberKnife® radiosurgery is as accurate – if not more so – as frame-based radiosurgery.

Full body capability & staged treatment

CyberKnife® is able to deliver precise, high-dose radiation not just to lesions in the brain but to the spine and to other organs throughout the body. Because no frame is required it can also perform “hypo-fractionated” or staged radiosurgery, where the total radiation dose is divided into 3-5 smaller doses. This is especially beneficial for treating lesions near sensitive structures and larger tumours because it better protects surrounding healthy tissue.

What is it like?

Arriving Wear comfortable clothing and no jewellery. Try to relax, knowing that this will be a painless procedure. Feel free to bring a list of questions to ask the CyberKnife® team. They are there to ensure your comfort and safety.

Positioning You will be asked to lie on the treatment table and be fitted with the custom mask or body mould made earlier during the set-up process. Generally, no sedation or anaesthesia is required because the treatment is painless.

Painless Treatment During treatment you will need to lie still. You will be awake throughout the entire procedure which typically lasts 30-90 minutes depending on the complexity of your tumour.

Bring your favourite CD to help you relax! You will be monitored on five video cameras and can speak to the surgeons during treatment.

The image guidance system periodically takes x-ray images and compares them to data from the CT scan to ensure that the radiation is targeted accurately to the treatment site.

Completion If you are undergoing single-session radiosurgery, your treatment is complete. You can usually leave and resume normal activity immediately.

If your physician prescribes a “hypo-fractionated” or staged treatment, this will be spread over three or five consecutive days.

Where is it available? There are centres offering Cyberknife Radiosurgery throughout the world and MHL represent three here in Europe - in Munich, focusing on brain - spine and lung; in Athens and Zurich of which both centres focus on all areas currently treatable with Cryberknife Radiosurgery.

What do I do next? Please visit our dedicated CyberKnife Sterotactic Radiosurgery website to complete an online prelimary assessment form and read about the centres we represent and what conditions they treat. www.cyberknifeservice.com