Robotic whole body stereotactic radiosurgery: clinical advantages of the Cyberknife integrated system

Radiosurgery is defined as the delivery of high doses of ionising radiation, in mono- or hypo- fractionated treatments, to destroy tumours or focal areas of pathology. The clinical requirements of designing a radiosurgical treatment system include providing: a) a highly precise beam delivery to targets located throughout the body, b) a highly conformal dose distribution, c) the ability to irradiate both small and/or large complex-shaped lesions while minimising the dose to adjacent radiosensitive tissues and d) the ability to interactively track lesion motion due to normal patient motion. To accomplish this, the CyberKnife radiosurgery system has pioneered in this area by taking advantage of the inherent geometrical targeting precision of a commercial arm-based robotic system carrying a compact X-band linear accelerator and integrated with X-ray imaging and visualisation feedback systems. The arm-mounted linear accelerator, equipped with patient specific anatomical models, registered to the patient in real-time with image guidance, dynamically and safely delivers conformal and homogeneous radiation for therapeutic benefit. This paper details the components of the CyberKnife system and their integration in the clinical workflow of radiosurgery.