Gamma Knife Surgery is a multi-disciplinary approach to the treatment of intracranial disorders, requiring the combined skills of neurosurgery, radiation oncology and medical physics. The average Leksell Gamma Knife procedure including frame fixation, neuro-imaging, treatment planning, and actual treatment requires one to three hours, so two or more complete patient procedures may easily be performed in one day.

1. Leksell Frame Fixation

The same frame is used for all imaging modalities, thereby allowing routine multimodality imaging for all cases.

The Leksell Stereotactic System® Frame is attached to the patient's head. The frame provides the basis for target coordinate determination and is used to immobilize and position the patient's head within the collimator helmet. General anesthesia is usually not employed, except in younger children.

2. Imaging

After frame fixation, an indicator box, compatible with the imaging modality to be used (CT, MRI, or angiography) is attached to the frame and the patient is imaged.

Once imaging is completed, the images are imported into the Leksell Gamma Knife's dedicated three-dimensional treatment planning system, Leksell GammaPlan. This is used to tailor the isodose curves to the target and to calculate the total dose and treatment time. In most cases, multiple isocenters (or 'shots') often of varying sizes, are placed on the lesion in 2-D and 3-D views to achieve a dose distribution which conforms to the lesion geometry. Additional tailoring of the dose may be achieved through the blocking of individual beam channels, an automated process in Leksell GammaPlan. Once the desired treatment protocol has been accepted, it is printed and forms the basis of the Leksell Gamma Knife treatment.

4. Treatment and Return to Pre-Operative Lifestyle

The patient is positioned on the unit's couch with the head within one of the four collimator helmets. The stereotactic frame is used to precisely position the lesion at the focal point of the cobalt-60 beams, once for each isocenter. The treatment is accomplished while the physician remains in intercom contact with the patient.

Following surgery, the patient can return to pre-operative lifestyle within 24 hours, without the need for intensive care or extended hospitalization.