A call to define stereotactic radiosurgery.

Stereotactic radiosurgery is the single-session, precise delivery of a therapeutically effective radiation dose to an imaging-defined target. Conceived and developed during the past 5 decades, stereotactic radiosurgery has involved significant advances, which have improved patient outcomes and made it a critical component of modern neurosurgical practice and training. In this article, a short history of stereotactic surgery and radiosurgery are presented, and radiosurgery is contrasted to radiation therapy. Adherence to accepted, descriptive terms in defining stereotactic radiosurgery and radiation therapy permits a clear distinction among the results of the different radiation delivery techniques for patients, physicians, and other interested parties.