 The GTV will then be expanded by an additional margin of 5.0 mm to create the PTV. This 5mm margin may be reduced, or eliminated around natural barriers to tumor growth such as the skull, ventricles, falx, etc, and also to allow sparing of the optic nervechiasm or other critical structure at the discretion of the treating physician. The minimum dose to the PTV will be 95 of the prescription dose 35Gy. The maximum dose to the PTV will be 110. Any beam arrangement and set of energies that accomplishes these criteria is allowed. 