To the Editor.
—Stereotaxic radiosurgery refers to a technique whereby an intracranial target can be destroyed by ionizing beams of radiation that are directed with stereotaxic precision, without the need for a surgical incision. Lars Leksell, MD, PhD, defined the field and the term in 1951.1-3 Working together with physicist Borje Larrson at the Gustav Werner Institute, Uppsala, Sweden, Leksell first used orthovoltage roentgenographic techniques, then a proton beam generated by a synchrocyclotron, and eventually a linear accelerator to deliver, in a single session, a high dose of radiation to a defined volume in the brain.Because of complexity and imprecision, Leksell subsequently abandoned work with these devices and instead he and Larrson arranged for construction of the first true stereotaxic radiosurgical unit, the gamma knife. In 1968, the first gamma knife was used under the direction of Leksell at an affiliated hospital of the Karolinska Institute in Stockholm.
Lunsford LD, Flickinger JC, Steiner L. The Gamma Knife. JAMA. 1988;259(17):2544. doi:10.1001/jama.1988.03720170020017