Patent ID: 9504854
Filing Date: 2016-11-29
CPC Classification: A61N,G21F,G21K

Claim Text:
1. A rotating gantry that is equipped with a particle beam irradiation apparatus that irradiates a charged particle beam onto an irradiation subject and that can rotate around an isocenter, wherein a shielding material that attenuates a leakage dose of a secondary radiation generated by collision of the charged particle beam with the irradiation subject is provided at a position that is situated at the side opposed to the particle beam irradiation apparatus with respect to the irradiation subject and through which a beam axis of the charged particle beam is obstructed during irradiation, said beam axis being an axis that passes through a center line of the charged particle beam, and wherein the shielding material is disposed in such a way that when the irradiation subject does not exist in the rotating gantry, a portion of the shielding material that intersects the beam axis of the charged particle beam, is attachable and detachable, or can move in a sliding manner and in the rotation-axle direction of the rotating gantry to prevent obstruction, by the shielding material, of the beam axis and to enable ascertainment of the isocenter and a floor reference mark.