Leksell Gamma Knife is a non-invasive neurosurgical tool for the treatment of small to medium size intracranial lesions. Gamma Knife was devised by Swedish neurosurgeon Lars Leksell in the1960s and Gamma Knife radiosurgery proved to be very effective in a variety of disorders. It uses ionizing radiation (gamma ray) from Co60 and precisely focused radiation on the target results in therapeutic effect without significant injury to the surrounding normal brain tissue.