Gamma Knife surgery is the gold standard for the treatment of intracranial pathology. Its clinical efficacy has been documented across nearly four decades, with more than 500,000 cases treated worldwide providing the data for 2,500+ publications in peer-reviewed medical literature. It is used as the performance standard against which other technologies (such as CyberKnife) are measured.

Perhaps the easiest way to state our case is to compare, point for point, the Gamma Knife with the CyberKnife.

Gamma Knife Perfexion CyberKnife
192 source cobalt unit designed exclusively for non-invasive brain surgery, with 100x less radiation to the body than the Cyberknife, thereby decreasing the chance of radiation induced complications. Single source linear accelerator with robotic arm to compensate for patient movement during treatment; not exclusively used for intracranial SRS
Radiologic accuracy better than 0.5mm ** 1 mm accuracy; dose outside the target area is 2-6x greater than with GK
Rigid immobilization to prevent head movement using a lightweight stereotactic head frame fixed to the outer skull. Provides exact MR and CT correlation from planning to radiosurgical delivery in 3D. Non-rigid immobilization reduces head movement by using a thermoplastic face mask that is shrink-wrapped to the table during treatment. Provides relative MR and CT correlation from planning to treatment delivery in 3D. The moving target and moving radiation source are inherently less accurate than a fixed target and fixed source.
Treatment delivered during one session Single or multiple treatments, possibly over a period of days to weeks.

** Elekta guarantees that Leksell GK systems will perform with a total radiological accuracy of 0.50 mm or better. A study of 189 installed systems, based on 332 commissioning protocols, proved an average radiological accuracy of 0.15mm.