169 results about "Multi leaf collimator" patented technology

The invention is intended to shorten a positioning time required for forming an irradiation area with high accuracy using a number of leaf plates, and to reduce physical and mental burdens imposed on patients. A multi-leaf collimator comprises leaf plate driving body each including a plurality of movable leaf plates and provided respectively on one side and the other side, the plurality of leaf plates of the leaf plate driver on one side and the plurality of leaf plates of the leaf plate driver on the other side being disposed in an opposing relation to form an irradiation field of a radiation beam between the opposing leaf plates. Each of the leaf plate driving body includes a motor provided in common to the plurality of leaf plates. Driving force of the motor can be transmitted to the plurality of leaf plates at the same time through a pinion gear, upper and lower air cylinders, and upper and lower guides. Also, the driving force can be cut off selectively for each leaf plate.

A multi-leaf collimator is disclosed which alleviates the problems of inter-leaf leakage and pixellation. The collimator comprises a first multi-leaf collimator set, a second multi-leaf collimator set at an acute angle to the first, and a third multi-leaf collimator set at an acute angle to the second. Each multi-leaf collimator set will usually include a pair of leaf banks mutually opposed to each other. The acute angle between the first and the second multi-leaf collimator set is preferably the same as the acute angle between the second and the third set. A suitable angle is about 60°. To improve the penumbra characteristics, (i) the leaves of the multi-leaf collimator closest to the radiation source can be deeper in the direction of the radiation than the leaves of a multi-leaf collimator more distant from the radiation source, (ii) the leaves of the multi-leaf collimator furthest from the radiation source can be shallower in the direction of the radiation than the leaves of a multi-leaf collimator closer to the radiation source, (iii) the tips of the leaves of the multi-leaf collimators can be rounded (iv) the radius of curvature of the tips of the leaves of the multi-leaf collimator closest to the radiation source can be greater than the radius of curvature of the tips of the leaves of a multi-leaf collimator more distant from the radiation source, and (v) the radius of curvature of the tips of the leaves of the multi-leaf collimator furthest from the radiation source can be less than the radius of curvature of the tips of the leaves of a multi-leaf collimator closer to the radiation source. In general, it is also preferred that the first multi-leaf collimator is closest to the radiation source, the third multi-leaf collimator is furthest from the radiation source, and the second multi-leaf collimator is between the first and third multi-leaf collimators.

System and method of determining whether a component of a radiation therapy system is operating within a dosimetric tolerance. The method can include the acts of generating a treatment plan for a patient, the treatment plan specifying a radiation amount to be delivered to the patient, delivering radiation to the patient according to the treatment plan, obtaining feedback during the delivery of radiation, the feedback related to one of a position, a velocity, and an acceleration for one of a multi-leaf collimator, a gantry, a couch, and a jaws, generating a mathematical model based on the feedback for one of the multi-leaf collimator, the gantry, the couch, and the jaws, calculating a delivered dose amount based on the mathematical model and treatment plan information, calculating a deviation in dose between the radiation amount specified in the treatment plan and the delivered dose amount, and determining whether the deviation in dose is within a dosimetric tolerance for the one of the multi-leaf collimator, the gantry, the couch, and the jaws.

A charged particle beam reduces treatment time in the uniform scanning or in the conformal layer stacking irradiation. In the uniform scanning, an optimum charged particle beam scan path for uniformly irradiating a collimator aperture area is calculated. In the conformal layer stacking irradiation, an optimum charged particle beam scan path for uniformly irradiating a multi-leaf collimator aperture area of each layer for each of the layers obtained by partitioning the target volume is calculated. Alternatively, a minimum irradiation field size that covers the multi-leaf collimator aperture area of each layer is calculated, and a scan path corresponding to the irradiation field size, prestored in a memory of a particle therapy control apparatus, is selected. The charged particle beam scan path is optimally changed in the lateral directions in conformity with the collimator aperture area in the uniform scanning or in each layer in the conformal layer stacking irradiation.

A multi-leaf collimator for use in a radiotherapeutic apparatus comprises a plurality of elongate narrow leaves arranged side-by side and supported in a frame, the frame having upper and lower formations for guiding each leaf into which extend ridges on the upper and lower edges of the leaves, thereby to allow the leaves to move in a longitudinal direction, the upper and lower formations being aligned so that the sides of the leaves when fitted are at a non-zero angle to the beam direction, the upper and lower ridges being located on the upper and lower edges of the leaves so that a line joining their centres is at a non-zero angle to the sides of the leaf, tilted relative to the sides in a sense opposite to that of the beam. An outer face of the upper and / or lower ridges can be aligned with a side face of the leaf, for ease of manufacture. A radiotherapeutic apparatus is also disclosed, comprising a source of radiation and a multi-leaf collimator for shaping the radiation emitted by the source, the multi-leaf collimator being as set out above.

A method and system for providing intensity modulated radiation therapy to a moving target is disclosed. According to a preferred embodiment of the invention, a treatment plan for providing radiotherapy using a multi-leaf collimator (“MLC”) comprises a plurality of sub-plans, each of which is optimized for a different phase of target movement. Movements of the treatment target are tracked in real time, and the choice of which sub-plan to implement is made in real time based on the tracked position of the target. Each of the sub-plans is preferably formulated to minimize interplay effects between target movements and MLC leaf movements, consistent with other planning goals. In addition, the sub-plans preferably include a predicted region corresponding to the next anticipated position of the target, in order to facilitate the transition to the next position.

Methods and devices for calibrating a radiotherapy system are disclosed. The method includes providing a detection medium that responds to exposure to ionizing radiation, and preparing a calibration dose response pattern by exposing predefined regions of the detection medium to different ionizing radiation dose levels. The method also includes measuring responses of the detection medium in the predefined regions to generate a calibration that relates subsequent responses to ionizing radiation dose. Different dose levels are obtained by differentially shielding portions of the detection medium from the ionizing radiation using, for example, a multi-leaf collimator, a secondary collimator, or an attenuation block. Different dose levels can also be obtained by moving the detection medium between exposures. The disclosed device includes a software routine fixed on a computer-readable medium that is configured to generate a calibration that relates a response of a detection medium to ionizing radiation dose.