Abstract: An apparatus for performing stereotactic radiosurgery using a stationary radiation source is comprised of a frame, a platform rotatably connected to the frame about a vertical rotational axis, a patient receiving menas, a means for rotating the platform and a means for adjusting the head of the patient to permit intersection of the radiation beam central axis with the vertical rotational axis at the location of the target site that is the subject of the radiosurgery. A method for performing stereotactic radiosurgery using the apparatus is also provided.

Abstract: A neutron shielded door has a hollow interior portion for containing a neutron retarding fluid. This neutron retarding fluid may consist of hydrogen rich compound, such as water, with a dissolved boron compound. This door contains internal baffles for preventing surging of the neutron retarding fluid when the door is opened and closed. The neutron shielded door is contemplated for use with radiation therapy rooms housing medical accelerators and other equipment which generate low levels of neutrons. Ports are provided for the input and drainage of neutron retarding fluid from the door and fluid indicators are provided for permitting determination of the amount of fluid contained in the door.