About Gamma Knife surgery


Gamma Knife surgery is used exclusively for the brain, head and neck. As of December 2006, 397,672 patients worldwide had undergone Gamma Knife surgery with an excellent record of successful and safe treatment.

 

Of these patients, 14% were treated for vascular malformations, 35% for benign tumours, 42% for malignant tumours, 8% for functional disorders and 1% for ocular disorders.

 

Gamma knife treatment stats

 

The Centre at Bupa Cromwell Hospital is the first in the UK to install the latest generation of Gamma Knife technology, the Leksell Gamma Knife PerfexionTM.

Gamma Knife Surgery - a patient's guide

A 12 page patient guide has been designed to explain in detail the treatment process you will experience whilst undergoing Gamma Knife Surgery at Bupa Cromwell Hospital. Read Gamma Knife Surgery - A Patient’s Guide (PDF).

 

A short history

  • 1951 Leksell, a professor in Neurosurgery in Sweden, introduces the concept of radiosurgery
  • 1967 The first Gamma Knife prototype is made and the first patient treated at Studsvik nuclear plant
  • 1968 The first patient is treated at the Karolinska, Sophiahemmet Hospital in Stockholm, Sweden
  • 1969 The first acoustic neuroma patient is treated
  • 1970 The first patient with an arteriovenous malformation is treated
  • 1974 An improved Gamma Knife prototype is installed at the Karolinska Hospital in Stockholm
  • 1974 Introduction of the first computer assisted dose planning program for the Gamma Knife
  • 1976 The first patient is treated for meningioma
  • 1985 New Gamma Knife prototypes are commissioned to Sheffield, U.K., and Buenos Aires, Argentina
  • 1987 The first Gamma Knife model for serial production is installed in Pittsburgh, USA
  • 1988 Gamma Knife series B is installed at the Karolinska Hospital, Sweden
  • 1989 The first publication on Gamma Knife surgery for cerebral metastases
  • 1990 Introduction of the Leksell Gamma Plan dose planning program
  • 1995 International Stereotactic Radiosurgery Society (ISRS) Fabrikant Award to Drs Larsson and Backlund for work with the Gamma Knife
  • 1996 Image fusion between CT and MRI available in the Leksell Gamma Plan
  • 1997 ISRS Fabrikant Award to Dr Lunsford
  • 1998 The first Gamma Knife is installed in London at the Cromwell Hospital
  • 1998 Semiautomatic outlining of target volumes available in the Leksell Gamma Plan
  • 1999 ISRS Fabrikant Award to Professor Lindquist of the Cromwell Hospital
  • 2000 Introduction of the Model C, using the automatic Positioning System (APS), allowing remote movement of the patient during treatment
  • 2003 Cromwell Hospital gains NHS Accreditation
  • 2006 Cromwell treats 1,000 patients
  • 2006 Introduction of the Leksell Gamma Knife PerfexionTM
  • 2007 Leksell Gamma Knife PerfexionTM is installed at the Cromwell Hospital – the second in the world.

For further information read A full history of the Gamma Knife (PDF)  (you will need Adobe Acrobat Reader to read the guide. Click here to download your free version of Acrobat Reader.)

 

How Gamma Knife Surgery works

One of the main advantages of Gamma Knife Surgery is the ability to treat a very tightly defined target area without affecting surrounding tissue. This target area is pinpointed and mapped using an MRI scan and/or Angiogram, CT or PET/CT as required. 

Using the imaging information, a 3D model of the target area is developed. This model is then used to determine the number and level of doses needed to treat the condition. This treatment planning is done with the help of a computerised planning system.  

The patient is fixed to the treatment couch using the head frame, which ensures accurate positioning of the head. The Radiographer then administers the dose of radiation recommended by the physician. Each dose can take from one to fifteen minutes. For additional doses, the head is automatically repositioned and the procedure is repeated. The Gamma Knife itself works by focusing 192 beams of gamma radiation on the target area.

 

Technical description

The Leksell Gamma Knife provides the proven advantages of Gamma Knife surgery coupled with enhanced features such as superior dosimetry performance that sets new standards in radiosurgery. The patented collimator design provides a virtually unlimited ability for sculpting the dose distribution, enabling dynamic shaping with absolute accuracy.

 

Gamma knife technical

 

A typical procedure

The entire Gamma Knife procedure takes from between three and six hours, depending on the condition being treated. Patients are usually admitted to the Hospital on the day of treatment and will normally stay overnight after treatment for observation.

 

Fixing the frame

Gamma knife frame

In order to pinpoint the area that will be treated by the Gamma Knife, a lightweight aluminium guiding device, called a stereotactic frame, is fitted to the patient’s head with four pins. This is done under local anaesthetic to reduce any discomfort. Fixing the frame takes about twenty minutes.

 

Imaging

An MRI scan is then taken to locate the area to be treated.  A cerebral angiogram may also be performed if the treatment is for a blood vessel malformation. In a few cases, a CT or PET/CT scan may also be recommended.

 

Planning

While the patient rests, the medical team plans the treatment and determines the appropriate dose. This is done with the aid of an advanced 3D computerised planning system and generally takes one to two hours, depending on the lesion and the number of positions needed to treat it.

 

Treatment

Gamma knife treatment

Once the planning is completed, the patient will be moved to the treatment room and positioned on the cushioned table of the Gamma Knife. The stereotactic frame is then attached to the Gamma Knife positioning system on the treatment couch.

 

The medical team will leave the room during the actual treatment, but patients are able to be seen via cameras in the treatment room. The patient can speak to the medical team at any time using the two-way intercom. Patients will not feel any different while the treatment is being given and will not experience any pain. The treatment plan may require one or more doses of gamma radiation, each lasting from one to fifteen minutes. After each dose, the treatment couch will automatically position the patient ready for the next dose.

 

Click for a more detailed patient guide (PDF).