Design of a moving bed for a radiation therapy system with multiple linear accelerators

Radiation therapy system is preferred to surgery for the most cancer because it is noninvasive. In radiotherapy, respiratory motion is an obstacle of high-precision therapy. The patient support system (PSS) is a method to compensate respiratory motion without increasing treatment time. But treatment time could not be decreased dramatically with conventional PSS because it increases duty cycle of linear accelerator (LINAC). To apply multiple LINACs, the conventional PSS is not suitable as the structure of PSS interrupt workspace of LINACs. In this study, we designed a new moving bed to apply multiple LINACs as well under the bed. A force distribution method and dynamics of the bed were identified. Rigid body simulation model was made to verify that the bed can operate well as expected. And a real size model was manufactured on a basis of the simulation model. Experiments were conducted to identify that the bed can move in desired objectives.