| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a multileaf collimator for employing both broad irradiation and high resolution irradiation. <P>SOLUTION: The multileaf collimator includes: pairs of leaves 2 configured to arrange, in the direction of thickness t<SB POS="POST">L</SB>, a plurality of a pairs of leaves 1 whose end faces 1Le and 1Re are disposed so as to oppose to each other; a drive mechanism 4 for driving each leaf plate of the pairs of the leaves 2 in the direction close to or away from each opposing leaf plate; and a drive mechanism 5 for driving the pairs of the leaves 2 in the direction of the thickness t<SB POS="POST">L</SB>. In at least a pair of leaves 1(w) of the pairs of the leaves 1, the opposing end face of each leaf plate is formed stepwise when viewed from the direction of the thickness t<SB POS="POST">L</SB>so that a distal end of the each leaf plate overlaps to each other, viewed from an irradiation direction of particle beams, when driving the leaf plates in a direction close to each other. In at least one leaf plate, a cutout portion is also formed on the end face at the most distal end toward the other leaf plate of the stepwise end faces. <P>COPYRIGHT: (C)2012,JPO&INPIT |
