Patent Number: 062663933
Section: abstract

A multileaf collimator (12) for use in a radiation system (10) providing a radiation beam (20) in a given beam direction, including a first layer (30) of a plurality of radiation blocking leaves (32), the leaves (32) being arranged adjacent one another so as to form two opposed rows of adjacently positioned leaves (32) and being movable in a longitudinal direction (Y) (34) which is generally traverse to the beam direction so as to define a radiation beam shaping field (36) between the opposed ends of the leaves (32), a second layer (40) of a plurality of radiation blocking leaves (42), the leaves (42) of the second layer (40) being arranged adjacent one another so as to form two opposed rows of adjacently positioned leaves (42) and being movable in a cross-over direction (X) (44) which is generally traverse to the beam direction and angled with respect to the longitudinal direction (Y) (34) so as to define a radiation beam shaping field (46) between the opposed ends of the leaves (42) of the second layer (40), and actuator apparatus (38, 48) for moving the leaves (32) of the first layer (30) in the longitudinal direction (Y) (34) and the leaves (42) of the second layer (40) in the cross-over direction (X) (44), wherein the first (30) and second (40) layers are arranged one above another in an overlapping manner in the beam direction.