The accuracy of dose localization for an image-guided frameless radiosurgery system.

A compact X-band accelerator mounted on a robotic arm is under development for frameless stereotaxic radiosurgery. The therapy beam is aimed at the lesion by an imaging system comprised of two diagnostic x-ray cameras that view the patient during treatment. Patient position and motion are measured by the cameras and communicated in real time to the robotic arm for beam targeting and patient motion tracking. The tests reported here measured the pointing accuracy of the therapy beam and the present targeting and tracking capability of the imaging system. The results show that the system achieves the same level of targeting precision as conventional frame-based radiosurgery.