APPARATUS FOR STEREOTACTIC RADIOSURGERY.

摘要

Stereostactic radiosurgery apparatus for eliminating misalignments due to mechanical inaccuracies and sag of a linear accelerator radiation-emitting head which is swung through an arc comprises a guiding and support structure with a first bearing system for accurately rotating a collimator through a precise arc in a vertical plane with respect to a predetermined center point in the plane corresponding to a treatment location, a second gimbal bearing system for coupling the collimator to the head so that the rotating head can drive the collimator through its arc while mechanically uncoupling the head from the collimator by eliminating torques and forces on the collimator which would be exerted by mechanical inaccuracies or sag of the head, and a third bearing system for rotatably supporting a stereotactic floorstand for rotation about a vertical axis which intersects the center point. Since the movement of the collimator and the rotation of the floorstand are precisely controlled with respect to the center point, the apparatus ensures that radiation from the head will be accurately focused at the center point for all rotational positions of the head and floorstand. Mechanical linking arrangements are shown for allowing the floorstand to rotate automatically upon rotation of a patient treatment table. Although the linking arrangements are used to drive the rotation of the floorstand, the linkage arrangements prevent the introduction of positional inaccuracies in the floorstand rotation.