Gamma Knife Radiosurgery was invented by a Swedish scientist, Lars Leksell. First patient was treated in 1968. 1997 was the first year when the technique was used in Turkey. The device is manufactured by Elekta. Gazi University has installed Gamma Knife device on 2005 and since then has treated over 10 000 patients successfully. Gazi University Department of Neurosurgery has the Gamma Knife Perfexion Model in use.