MULTILEAF COLLIMATOR, PARTICLE BEAM THERAPY APPARATUS, AND RADIOTHERAPY PLANNING SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a multileaf collimator forming a high-contrast field without influence of penumbra, and to provide a particle beam therapy apparatus.;SOLUTION: The multileaf collimator includes a leaf row 5_C having a plurality of leaf plates 5_L disposed in a thickness direction with their one end surfaces E_L aligned, a leaf plate-driving mechanism 5_D for driving one end surfaces E_L of the plurality of leaf plates 5_L in an approaching or separating direction relative to a beam axis X_B. Each of the leaf plates 5_L has a curved surface having two different curvature radii according to directions, and the two curvature radii have a first axis as the axis of one curvature radius which passes through a first reference point on a beam axis X_B, and a second axis as the axis of the other curvature radius which passes through a second reference point on the beam axis X_B, separated from the first reference point.;COPYRIGHT: (C)2012,JPO&INPIT