Abstract: A radiation therapy patient couch top which provides optimal fields of treatment in a high-energy radiation therapy environment. In addition, the patient couch top provides superior imaging qualities when used in a diagnostic imaging x-ray environment. All metal is eliminated from the treatment/imaging area. This ensures that no metal will be in the way of the radiation treatment beam and that no artifacting will occur when used with diagnostic imaging techniques such as Computed Tomography. By employing moveable fiber reinforced support beams, the main patient support structure can be positioned so that a minimum of electron generation will occur through Compton scattering. By allowing for a removable insert, the top patient surface can be optimized for treatment, diagnostic imaging or the addition of other useful features.