Stereotactic radiosurgery: at the threshold or at the crossroads?

More than 15,000 patients worldwide have undergone stereotactic radiosurgery since the technique was first described in 1951. Over 6000 of these patients had arteriovenous malformations, usually relatively small. Increasingly, patients with benign and malignant brain tumors have had radiosurgery as an alternative to microsurgical removal. The role of radiosurgery as a tool for functional neurosurgery is being evaluated further. Numerous studies over the past 10 years have examined the benefits and risks of radiosurgery performed with various devices (cyclotron-generated particle beams, the multisource cobalt-60 gamma knife, and modified linear accelerators). As radiosurgical centers continue to proliferate, often without appropriate regulatory review, lamentable lapses in appropriate patient selection, quality assurance, training, and results analysis may ensue. Critical clinical and radiobiological questions (dose, histology, and volume variables) remain to be answered in appropriate studies; these needs can no longer be ignored by governmental funding sources. Stereotactic radiosurgery is a multidisciplinary field, requiring the leadership of neurological surgeons in cooperation with radiation oncologists, radiologists, and medical physicists. For many indications, stereotactic radiosurgery appears poised at both the threshold and at the crossroads. As clinical application progresses, continued dialogue between neurological surgeons and their professional colleagues is necessary to guide proper patient management decisions.