Varian Medical Systems, Inc.

Magdalena Constantin

HsinLu Hsu

Stuart Scollay

Marcelo Cassese

Robert Kopels

Jonathan Evans

Hsinlu Hsu

An example computer-implemented method for tuning a beam spot in a radiation therapy system has been disclosed. The example method includes configuring an electron beam to generate a first beam spot on an electron-beam target of the radiation therapy system, generating, using an imager of the radiation therapy system, a first plurality of projection images of the first beam spot, wherein each of the projection images of the first beam spot is generated with a line of sight blocked between the imager and a different respective portion of the beam spot, based on the first plurality of projection images, determining a value for one or more beam spot quality metrics associated with the first beam spot, and based on the value, determining whether the first beam spot is outside a specified quality range.

Beam spot tuning in a radiation therapy system

An example computer-implemented method for tuning a beam spot in a radiation therapy system based on radiation field measurements has been disclosed. The example method includes configuring an electron beam to generate a first beam spot on an electron-beam target of the radiation therapy system, determining a value for one or more radiation field quality metrics for a first radiation beam that originates from the first beam spot, and based on the value, determining whether the first radiation beam is outside a specified quality range.

Beam spot tuning in a radiation therapy system based on radiation field measurements

A phantom setup and source-to-surface distance (SSD) verification method uses radiation images. In an exemplary method, a phantom is positioned on a support relative to a radiation source such that a surface of the phantom is horizontally leveled at or approximate to a desired value of SSD. The radiation source is then positioned at a gantry angle predetermined at least based on the desired value of SSD such that a ray of radiation from the radiation source aligns with a horizontal surface located at the desired value of SSD. An image is acquired using radiation from the radiation source at the predetermined gantry angle. Verification is performed to confirm, based on an analysis of the image, if the surface of the phantom is positioned at the desired value of SSD.

Phantom setup and source-to-surface distance verification using radiation imaging

In a method of constructing a head shield for a radiation machine, the angular distribution of radiation propagating from a source and the angular function of thickness of a material in attenuating the radiation to a certain level of its original value are determined. Based on the angular distribution of radiation from the source and the angular function of thickness of the material, the thicknesses of the material at a plurality of angular locations around the source and distances from the source can be calculated for attenuating the radiation to or less than a predetermined threshold value. A shield around the source is constructed based on the calculated thicknesses of the material through iterative steps to ensure a cost-saving, weight-efficient, optimal solution. A method of designing a local radiation shield for a point of interest in a radiation system is also described to improve the machine reliability, regardless of the motion component of the POI with respect to the main radiation source and the secondary radiation source created by the patient scatter.

Radiation shields for LINAC head and system

Radiation shields for linac head and system

A multileaf collimator assembly employs one or more static blocks to significantly reduce extra focal leakage or out of field dose. The multileaf collimator assembly includes a plurality of pairs of beam shaping leaves. The leaves of each pair are movable relative to each other in a longitudinal direction. The one or more static blocks are disposed adjacent to the outermost pair of beam shaping leaves and unmovable in the longitudinal direction. The material composition and geometric characteristics of the static blocks may be chosen based on the pre-determined leakage specification for a particular radiation apparatus in the patient plane.

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Los Altos, CA, United States of America

Magdalena Constantin