Developed in 1990, the Cyberknife® is a device that targets radiation therapy to a clearly defined therapeutic site more accurately than traditional radiotherapy. The two main components of the system are a small linear particle accelerator and a robotic arm. With the radiation source mounted to a robot, radiation therapy can be directed at a well-delineated anatomic site from a variety of directions and angles, with instant repositioning possible. X-ray image guidance helps the Cyberknife® accurately target tumors and other masses. Radiotherapists currently use the Cyberknife® to treat a variety of benign and malignant tumors, as well as other medical ailments.
The United States Food and Drug Administration (FDA) first approved the Cyberknife® for treatment of tumors in any body location in August 2001. Since its clearance, the system has been effectively used to treat multiple cancers, including tumors of the pancreas, liver, prostate, and spine. The system has not resulted in improved patient survival compared to that of conventional therapy. Because it is more accurate, however, the device lets doctors deliver of a higher dose of radiation in a shorter period with less collateral damage to normal tissue than would be possible with conventional therapy.
The Cyberknife® is unique among all of the radiosurgical devices in that it does not require a rigid frame for precise targeting. Conventional systems rely upon the connection of frames to a patient's skull with aluminum or titanium screws in order to ensure accurate radiation delivery. By comparison, the frame-free system of the Cyberknife® facilitates fast and precise treatment delivery by comparing on-the-fly image guidance X-rays to previously obtained computed tomography scans, allowing accurate correlation and specific patient repositioning on the robotic treatment bed, the RoboCouch®. This allows the possibility of dispensing the radiation dose over several days or weeks, a process called fractionation. Fractionation allows the healthy tissues to repair themselves while the tumor cells, with faulty repair mechanisms, continue to die.
Sold by a United States company, Accuray, the Cyberknife® is operational in approximately 150 locations worldwide, with 100 treatment facilities in the United States alone. About 40,000 patients have been treated with the system worldwide. The actor Patrick Swayze received radiation treatments for his pancreatic cancer using the Cyberknife® technology in 2008. Located near its development site, the first Cyberknife® unit was set up outside of Stanford University at Newport Diagnostic Center in Newport Beach, California. Stanford University has administered radiotherapy to more than 2,500 patients with the system.