In 1951, using the Uppsala University cyclotron, Lars Leksell and the physicist and radiobiologist Borje Larsson, developed the concept of Radiosurgery. Leksell and Larsson first employed proton beams coming from several directions into a small area into the brain , in experiments in animals and in the first treatments of human patients. Thus, he achieved a new non-invasive method of destroying discrete anatomical regions within the brain while minimizing the effect on the surrounding tissues.
First prototype of Gamma Knife was installed in Sophiahemmet in 1968. Over the rest of his career, Leksell treated 762 patients with the “Gamma Knife”. Throughout this time he would propose improving radiosurgery with modern imaging modalities including CT, MRI and angiography, as is currently used. Today, Leksell's technique is used as an effective treatment for many conditions such as arteriovenous malformations, pituitary tumors, acoustic neuromas, craniopharyngiomas, Meningioma, Matastatic and skull base tumors, and primary brain tumors. The Gamma Knife is manufactured by Elekta Instruments, Inc.
In Gamma Knife radiosurgery, specialized equipment focuses close to 200 tiny beams of radiation on a tumor or other target. Although each beam has very little effect on the brain tissue it passes through, a strong dose of radiation is delivered to the site where all the beams meet.
The precision of Gamma Knife radiosurgery results in minimal damage to healthy tissues surrounding the target. In some cases, Gamma Knife radiosurgery may have a lower risk of side effects compared with other types of radiation therapy. Also, Gamma Knife radiosurgery is often a safer option than is traditional brain surgery.
Gamma Knife radiosurgery is usually a one-time therapy completed in a single day.
The vast amount of clinical material and long-term evaluation now support the use of GK surgery in small hypothalamic hamartomas and media temporal lobe epilepsy (MTLE) when the patient is at risk of verbal memory loss 1).