Frameless image-guided intracranial and extracranial radiosurgery using the Cyberknife robotic system.

The Cyberknife is an image-guided robotic radiosurgery system. The image guidance system includes a kilovoltage X-ray imaging source and amorphous silica detectors. The radiation delivery device is a mobile X-band linear accelerator mounted onto a robotic arm. Through a highly complex interplay between the image guidance system, an automated couch, and the high-speed linear accelerator, near real-time tracking of the target is achieved. The Cyberknife gained Federal Drug Administration clearance in the United States in 2001 for treatment of tumors "anywhere in the body where radiation treatment is indicated." Because the Cyberknife system does not rely on rigid fixation of a stereotactic frame, tumors outside of the intracranial compartment, even those tumors that move with respiration can be treated with a similar degree of ease as intracranial targets. A description of the Cyberknife technology and a review of some of the current intracranial and extracranial applications are detailed herein.