| 摘要 |
In a particle beam irradiation method and a particle beam irradiation apparatus in which depth direction irradiation field spread and lateral direction irradiation field spread are performed, an irradiation dose in each of the irradiation layers of an irradiation target is made substantially constant, the control is simplified, and the irradiation error by the displacement of the irradiation target is reduced. The depth direction irradiation field spread is an active irradiation field spread to superimpose plural irradiation layers having different ranges in the irradiation direction of the particle beam. A bolus having a shape along a deepest part of the irradiation target in the depth direction is disposed to cross the particle beam. At least one irradiation layer selected from the plural irradiation layers is re-irradiated one or more times with the particle beam. |
