title: Stereotactic radiosurgery: comparing different technologies.
abstract: Radiosurgery can be defined as 3-dimensional stereotactic irradiation of small intracranial targets by various radiation techniques. The goal is to deliver, with great accuracy, a large, single fraction dose to a small intracranial target, while minimizing the absorbed dose in the surrounding tissue. This article describes certain technical aspects of radiosurgery and compares the different methods of performing such treatment. The 2 most frequently used types of devices for radiosurgery are units with multiple cobalt sources (e.g., the Gamma Knife) and those based on a linear accelerator. In the former, highly collimated beams of radiation from the cobalt sources intersect at the target. In the latter, the source of a highly collimated beam of high-energy photons directed at the target turns through an arc or set of arcs. The accuracy of target localization, the steepness of fall-off of the radiation dose outside the target and the ability to irradiate an irregularly shaped target are all comparable for these 2 types of devices, despite claims to the contrary.
authors.affiliation: Sunnybrook Health Science Centre, Toronto, Ont. m.schwartz@utoronto.ca
authors.forename: M
authors.initials: M
authors.lastname: Schwartz
mesh_terms: D006801:Humans; D016634:Radiosurgery / Q000191:economics / Q000295:instrumentation* / Q000379:methods; D016896:Treatment Outcome