Treatment planning device, particle beam therapy system and method for determining scanning route of charged particle beam

A treatment planning device by which a scanning route of a charged particle beam of a particle beam therapy system is determined, wherein the particle beam therapy system comprises an X-directional scanning electromagnet and a Y-directional scanning electromagnet for deflecting a charged particle beam in an X-direction and a Y-direction which are two perpendicular directions to a traveling direction of the charged particle beam so as for the charged particle beam to move and stay repeatedly and the charged particle beam is irradiated onto an affected part of a patient which is an irradiation objective,

• wherein the treatment planning device comprises
• a spot position storing unit which stores spot positions which are arranged in a grid shape in the X-direction and the Y-direction for each layer, which are points set in the affected part where the charged particle beam stays,
• a scanning candidate route extracting unit which extracts plural candidates of scanning routes in which each of the scanning routes connects all spot positions in one layer which are stored in the spot position storing unit,
• a scanning route evaluating unit which evaluates each scanning route based on time which is required for scanning the charged particle beam in each scanning route of the plural candidates which are extracted by the scanning candidate route extracting unit, and
• a scanning route determining unit which determines a scanning route which is used for therapy based on a result which is evaluated by the scanning route evaluating unit.