Abstract: Disclosed herein is a radiation head for a radiotherapy device. The radiation head comprises a source of radiation configured to emit a beam of radiation; and beam shaping device for collimating the beam of radiation. The beam shaping device comprises a multi-leaf collimator; and a diaphragm positioned between the source and the multi-leaf collimator. The diaphragm comprises a diaphragm block movable along a curved path, the diaphragm block having a flat face focused on a focus point which is offset from the source of radiation.

Abstract: A multi-leaf collimator module for a radiotherapy device comprises: a leaf bank comprising a plurality of leaves. The module also comprises a leaf guide arranged to guide linear movement of the leaves in a first direction and a second direction opposite the first direction, the leaf guide being in direct contact with the leaves. The module further comprises a plurality of leaf actuators, each leaf actuator arranged to engender relative linear motion in the first direction and second direction between one leaf in the leaf bank and other leaves in the leaf bank; and a leaf bank actuator arranged to engender relative linear motion in the first direction and second direction between the entire leaf bank and the leaf guide.

Abstract: A leaf for a multi-leaf collimator comprises a leaf portion for delineating a beam of radiation, the leaf portion having first attenuation factor. The leaf also comprises a tail portion having a second attenuation factor, the first attenuation factor being greater than the second attenuation factor.

Abstract: A leaf assembly for a multi-leaf collimator comprises a leaf and a leaf nut removably mounted within the profile of the leaf, the leaf nut comprising a threaded hole for receiving a leaf actuator screw oriented along a first axis in the plane of the leaf. The leaf nut is mounted within the leaf such that relative movement between the leaf nut and the leaf is prevented both linearly along the first axis and rotationally about the first axis.

Abstract: A mount for an array of leaf drive units corresponding to a single leaf bank of a multi-leaf collimator comprises a plurality of separable mounting plates. Each mounting plate comprises an array of mounting holes, and each mounting hole is arranged to receive a respective one of the leaf drive units.

Abstract: A leaf unit assembly for a multi-leaf collimator comprises a leaf, a leaf actuator screw having a first end fixedly attached to the leaf, and a rotatable part threadably engaged with the leaf actuator screw.

Abstract: A computer-implemented method for calibrating a multi-leaf collimator of a radiotherapy device. The multi-leaf collimator comprises a plurality of leaves, each leaf comprising an imaging marker, wherein the radiotherapy device includes an imaging device configured to image the leaves. The method comprises: receiving, from the imaging device, an image of the multi-leaf collimator in a calibration position, wherein in the calibration position the tips of the leaves abut an edge of a rigid calibration block, the edge having a known calibration profile; calculating for each leaf, from the calibration profile and the location of the marker in the image, a minor offset of the marker relative to a reference point; and outputting calibration values based on the calculated minor offsets, wherein at least one leaf of the multi-leaf collimator is controlled based on the calibration values.

Abstract: A collimator for a radiotherapy apparatus, comprising a block of isolation-attenuating material having a front face forming the leading edge of tie block and at least one main rear face defining the trailing edge of the block, in which the or each rear face is substantially planar in the direction of the depth of the block and non-parallel to the front face. The collimator may form part of a radiotherapy apparatus, and methods of operation of such apparatus are described.

Abstract: A collimator for a radiotherapy apparatus, comprising a block of isolation-attenuating material having a front face forming the leading edge of tie block and at least one main rear face defining the trailing edge of the block. In which the or each rear face is substantially planar in the direction of the depth of the block and non-parallel to the front face. The collimator may form part of a radiotherapy apparatus, and methods of operation of such apparatus are described.

Abstract: A collimator for a radiotherapy apparatus comprising a block of radiation-attenuating material having a front face forming the leading edge of the block and at least one main rear face defining the trailing edge of the block, in which the least one main rear face has a material disposed thereon and is non-parallel to the front face. The collimator may form part of a radiotherapy apparatus, and methods of operation of such apparatus are described.

Abstract: A collimator for a radiotherapy apparatus comprising a block of radiation-attenuating material having a front face forming the leading edge of the block and at least one main rear face defining the trailing edge of the block, in which the least one main rear face has a material disposed thereon and is non-parallel to the front face. The collimator may form part of a radiotherapy apparatus, and methods of operation of such apparatus are described.

Abstract: A collimator for a radiotherapy apparatus, comprising a block of radiation-attenuating material having a front face forming the leading edge of the block and at least one main rear face defining the trailing edge of the block, in which the or each rear face is substantially planar in the direction of the depth of the block and non-parallel to the front face. The collimator may form part of a radiotherapy apparatus, and methods of operation of such apparatus are described.

Abstract: A collimator for a radiotherapy apparatus, comprising a block of radiation-attenuating material having a front face forming the leading edge of the block and at least one main rear face defining the trailing edge of the block, in which the or each rear face is substantially planar in the direction of the depth of the block and non-parallel to the front face. The collimator may form part of a radiotherapy apparatus, and methods of operation of such apparatus are described.

Abstract: A multi-leaf collimator for a radiotherapy apparatus comprises at least one array of laterally-spaced elongate leaves, each leaf being driven by an associated motor connected to the leaf via a drive means so as to extend or retract the leaf in its longitudinal direction, the drive means comprising a sub-frame on which at least a subset of the motors are mounted, the sub-frame being mounted at a location spaced from the leaf array in a direction transverse to the lateral and longitudinal directions, and including a plurality of threaded drives disposed longitudinally, each being driven by a motor and being operatively connected to a leaf thereby to drive that leaf.

Abstract: The present disclosure relates to a seamless model free of bond lines made by a method which includes the steps of providing a substructure having an exposed outer surface, applying a modeling paste to the outer surface of the substructure in the form of a continuous layer, curing the continuous layer of applied modeling paste, and machining said cured layer of modeling paste to the desired contour to form the seamless model. The modeling paste may be a mechanically frothed syntactic foam prepared by injecting inert gas with mechanical stirring into either a formed froth-forming polyurethane or epoxy composition containing microballoons.

Abstract: Embodiments of the present invention provide a multi-leaf collimator with a plurality of leaves and at least one motor for each leaf. The motor for each leaf has a lateral width which is equal to or narrower than the corresponding leaf, and in this way the motors can be arranged within the lateral extent of the leaf. A cut-out section in the leaf allows the motor to lie at least partially within the depth of the leaf, and in this way the drive mechanism and the multi-leaf collimator as a whole are made extremely compact. This in turn allows the leaves to be deeper than would otherwise be the case, increasing their efficacy in blocking radiation.

Abstract: The present disclosure relates to a seamless model free of bond lines made by a method which includes the steps of providing a substructure having an exposed outer surface, applying a modeling paste to the outer surface of the substructure in the form of a continuous layer, curing the continuous layer of applied modeling paste, and machining said cured layer of modeling paste to the desired contour to form the seamless model. The modeling paste may be a mechanically frothed syntactic foam prepared by injecting inert gas with mechanical stirring into either a formed froth-forming polyurethane or epoxy composition containing mieroballoons.

Abstract: The invention relates to a seamless model free of bond lines and to a method of making same. The method includes the sequential steps of providing a substructure having an exposed outer surface, applying a modeling paste to the outer surface of the substructure in the form of a continuous layer, curing the continuous layer of applied modeling paste, and machining said cured layer of modeling paste to the desired contour. The modeling paste of the invention is a mechanically frothed syntactic foam prepared by injecting inert gas with mechanical stirring into either a formed froth-forming composition, which is preferably a polyurethane or epoxy froth-forming composition containing microballoons.

Abstract: A multi-leaf collimator for a radiotherapy apparatus comprises at least one array of laterally-spaced elongate leaves, each leaf being driven by an associated motor connected to the leaf via a drive means so as to extend or retract the leaf in its longitudinal direction, the drive means comprising a sub-frame on which at least a subset of the motors are mounted, the sub-frame being mounted at a location spaced from the leaf array in a direction transverse to the lateral and longitudinal directions, and including a plurality of threaded drives disposed longitudinally, each being driven by a motor and being operatively connected to a leaf thereby to drive that leaf.

Abstract: A multi-leaf collimator for a radiotherapy apparatus comprises at least one array of laterally-spaced elongate leaves, each leaf being driven by an associated motor connected to the leaf via a drive means so as to extend or retract the leaf in its longitudinal direction, the drive means comprising a sub-frame on which at least a subset of the motors are mounted, the sub-frame being mounted at a location spaced from the leaf array in a direction transverse to the lateral and longitudinal directions, and including a plurality of leadscrews disposed longitudinally, each being driven by a motor and being operatively connected to a leaf thereby to drive that leaf.