Patent ID: 7629598
Filing Date: 2009-12-08
Classification: A61B,A61N,G21K

Abstract:
1. A particle beam irradiation method which uses both a depth direction irradiation field spread for spreading an irradiation field of a particle beam in a depth direction along an irradiation direction of the particle beam, and a lateral direction irradiation field spread for spreading the irradiation field of the particle beam in a lateral direction perpendicular to the irradiation direction of the particle beam, and irradiates the particle beam at an irradiation target, the method comprising: superimposing plural irradiation layers having different ranges in the irradiation direction of the particle beam, the depth direction irradiation field spread being an active irradiation field spread; disposing a bolus having a shape along a deepest part of the irradiation target in the depth direction is disposed to cross the particle beam; re-irradiating at least one selected irradiation layer selected from the plural irradiation layers one or more times with the particle beam for irradiating a planned irradiation dose of the particle beam for the one selected irradiation layer, the one selected irradiation layer is a deepest irradiation layer among the plural irradiation layers; detecting a displacement of the irradiation target when the irradiation target is displaced; and adjusting an irradiation dose of the particle beam according to the displacement of the irradiation target so that the planned irradiation dose of the particle beam for the one selected irradiation layer is obtained, even if the one selected irradiation layer is displaced.