Neurosurgery was the first surgical specialty to use image-guided techniques, beginning with stereotactic frames that were attached to the patient’s cranium before the imaging process and remained in place during surgery. The relationship between the frame and lesion observed in the image was used to guide the instruments within the brain. Newer image-guided techniques, sometimes called frameless stereotaxy, use less invasive fiducially markers or video images for registration and optical trackers for navigation of hand-held instruments. To enhance stability, accuracy and ease of use, a number of robotic systems have been developed for these procedures.
One issued in image-guided neurosurgery is shifting of the brain during the procedure, which alters the spatial relationship between the preoperative image data and the anatomy of the patient. Various solutions have been proposed to deal with this problem, including deformable templates for non-rigid registration, sometimes base on biomechanical models of soft tissue. Another solution is to perform the procedure inside an imaging system, which permits continuous monitoring of the anatomy and instrumentation. This requires robotic manipulators that are compatible with the imaging modality and space constraints.
Radiosurgery uses a beam of radiation as a surgical instrument to destroy brain tumors. If the angle of incidence of the beam is pivoted through a large range, the beam passes through the tumor at all times but intersects each point of adjacent tissues only briefly.
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