CyberKnife radiosurgery in neurosurgical practice

Gamma Knife radiosurgery revolutionized neurosurgical care for intracranial tumors, arteriovenous malformations, and functional disorders. A new generation of radiosurgical devices exemplified by the frameless, image-guided, robotic CyberKnife (Accuray, Inc, Sunnyvale, CA) extends the benefits of precise, stereotactic delivery of ablative doses of radiation to the spine and other extracranial targets not easily treated by the Gamma Knife. In this review, CyberKnife technology and applications in neurosurgery are described. Eliminating the stereotactic frame allows the CyberKnife to provide a far more comfortable treatment experience for patients and makes it easier to treat lesions in multiple sessions, thereby extending to radiosurgery the potential radiobiologic benefits of dose hypo fractionation. Robotic radiation delivery allows treatment plans to be nonisocentric, conforming more readily to complex, nonspherical lesion volumes. The ability to treat extracranial sites may be a significant benefit to neurosurgeons because institutions may be more likely to adopt radiosurgical technology that has applications beyond neurosurgical practice.