Patent ID: 8890097
Filing Date: 2014-11-18
Classification: A61N,G21K

Abstract:
1. A multileaf collimator that is disposed on a beam orbit of an accelerated charged particle beam and that limits or forms an irradiation field of the charged particle beam in such a way that the irradiation field conforms to an irradiation subject, the multileaf collimator comprising: a leaf row in which a plurality of leaf plates are arranged in the thickness direction thereof in such a way that the respective one end faces of the leaf plates are trued up; and a leaf plate drive mechanism that drives each of the plurality of leaf plates in such a way that the one end face approaches or departs from a beam axis of the charged particle beam, wherein each of the plurality of leaf plates has at least one curved surface having two different curvature radiuses in respective directions, wherein a first axis that is the center axis of one curvature radius out of the two curvature radiuses passes through a first reference point on the beam axis, and wherein a second axis that is the center axis of the other curvature radius passes through a second reference point that is on the beam axis and apart from the first reference point.