Gamma Knife Radio Surgery
Gamma Knife is an extremely sensitive and efficient device, also referred as radiosurgery, which uses radiation beams to treat intracranial tumors. Neurosurgeons, using this modality, focus radiation beams directly and accurately to the target area, with no negative influence on intact surrounding tissue. Radiosurgery enables neurosurgeons focus radiation beams directly and accurately to the target area, with no negative influence on intact surrounding tissue.
Studies demonstrated that Gamma Knife surgery has high success rate. For instance, a tumor at any localization in the brain can be controlled by >85 % (or in other words, tumor is successfully debulked). This modality is referred as Gamma Knife, since the radiosurgery (single-session treatment) has accurate efficiency on the target area and resultant changes are “surgical” in nature. However, no blade or scalpel is used, on the contrary to the name of the method. Therefore, this surgery is scalpel-free and bloodless and the complication risk is very low.
Use of three-dimensional computer-assisted planning and absolute immobility of the patient minimize delivery of radiation beams to intact brain tissue.
Approximately 200 cobalt-60 sources are loaded in each treatment unit. Those sources may generate thousands of beams, as thin as approximately a hair, at a very high sensitivity level (greater than 0.5 mm). Such beams are weak enough to have no hazardous influence of normal tissue through the tract to the target. However, when they are accurately focused on the target, beams merge in order to be sufficient for treating the target area.
On the contrary to multiple visits for linear accelerator (LINAC) therapies (fractional therapy) which use lower fractional doses, whole therapeutic dose can be given in single session, since Gamma Knife radiosurgery is extremely sensitive. Minimization of radiation dose is important for everybody, but especially for patients with cancer who are already maintained on other radiotherapy options. If low-sensitivity therapies are used for such patients, treatment may take up to 6 weeks for metastatic brain tumor, which implies a cancer spreading from the primary focus to other body parts.