Multileaf collimator and radiation treatment device
View Patent ↗This multileaf collimator is provided with multiple leaves which limit the area irradiated by a radiation beam and which are arranged in the thickness direction. Each of the leaves is provided with a protruded portion which is formed protruding towards a first surface of the leaf, a depressed portion which is formed in the second surface of the leaf and into which the protruded portion formed on another leaf is inserted, a first curved surface which is formed between the first surface of the leaf and the lateral surface of the protruded portion, and a second curved surface which is formed between the second surface of the leaf and the lateral surface of the depressed portion.
1. A multileaf collimator for regulating a range irradiated with a radiation beam, comprising:
a plurality of leaves arranged along a thickness direction, wherein
each of the plurality of leaves comprising;
a protruded portion protrudingly formed on a first side surface in a plate thickness direction of the leaf,
a depressed portion formed in a second side surface in the plate thickness direction of the leaf, and configured to receive insertion of the protruded portion formed on another one of the plurality of leaves,
a first curved surface formed between the first side surface of the leaf and a lateral surface of the protruded portion, and
a second curved surface formed between the second side surface of the leaf and a lateral surface of the depressed portion.
2. The multileaf collimator according to claim 1 , wherein:
when a gap g 1 between two leaves, among the plurality of leaves, the two leaves being positioned side by side in the thickness direction, and a gap g 2 between the lateral surface of the depressed portion in a first one of the two leaves and the lateral surface of the protruded portion in a second one of the two leaves satisfy a relationship of:
g 1< g 2,
a radius R of curvature of the first curved surface and the second curved surface satisfies a relationship of:
R≤g 1.
3. The multileaf collimator according to claim 1 , wherein:
when a gap g 1 between two leaves, among the plurality of leaves, the two leaves being positioned side by side in the thickness direction, and a gap g 2 between the lateral surface of the depressed portion in a first one of the two leaves and the lateral surface of the protruded portion in a second one of the two leaves satisfy a relationship of:
g 2≤ g 1,
a radius R of curvature of the first curved surface and the second curved surface satisfies a relationship of:
R≤g 2.
4. The multileaf collimator according to claim 1 , wherein:
when a gap g 1 between two leaves, among the plurality of leaves, the two leaves being positioned side by side in the thickness direction and a gap g 2 between the lateral surface of the depressed portion in a first one of the two leaves and the lateral surface of the protruded portion in a second one of the two leaves satisfy a relationship of:
g 1≤ g 2,
a radius R of curvature of the first curved surface and the second curved surface satisfies a relationship of:
g 1≤ R≤g 2.
5. The multileaf collimator according to claim 1 , wherein
when a gap g 1 between two leaves, among the plurality of leaves, the two leaves being positioned side by side in the thickness direction and a gap g 2 between the lateral surface of the depressed portion in a first one of the two leaves and the lateral surface of the protruded portion in a second one of the two leaves satisfy a relationship of:
g 2≤ g 1,
a radius R of curvature of the first curved surface and the second curved surface satisfies a relationship of:
g 2≤ R≤g 1.
6. A radiation treatment apparatus, comprising:
the multileaf collimator according to claim 1 , and
a radiation beam irradiation device that irradiates the multileaf collimator with the radiation beam.