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US 11,691,031 B2Granted
Systems, methods, and devices for radiation beam asymmetry measurements using electronic portal imaging devices
AssigneeSiemens Healthineers International AG
InventorsReto Ansorge, Mathias Lehmann, Stefan J. Thieme-Marti
Life of this patent
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Abstract
Systems and methods for determining beam asymmetry in a radiation treatment system using electronic portal imaging devices (EPIDs) without implementation of elaborate and complex EPID calibration procedures. The beam asymmetry is determined based on radiation scattered from different points in the radiation beam and measured with the same region of interest ROI of the EPID.
Claims19
A method for calibrating a radiation system, comprising:
- measuring, using an electronic portal imaging device, radiation scattered relative to an axis of the radiation system;
- calculating an asymmetry value from the measured scattered radiation, the asymmetry value representing a measure of radiation beam symmetry relative to the axis;
- determining one or more parameters of the radiation system based on the calculated asymmetry value;
- determining whether the one or more parameters fall within corresponding prescribed ranges;
- and
- adjusting one or more control elements of the radiation system affecting the one or more parameters based on a result of the determining,
- wherein the radiation is scattered by a scatter probe positioned in the radiation field of the radiation system, and
- wherein the measuring of the scattered radiation by the scatter probe comprises:
- moving the scatter probe from a first location to a second, symmetric location in the radiation field, the moving being around an axis of rotation of a collimator of the radiation system;
- irradiating the scatter probe at the first and second locations with radiation;
- and
- measuring radiation scattered by the scatter probe at the first location and radiation scattered by the scatter probe at the second location using the electronic portal imaging device.
9 more elements
A method for calibrating a radiation system, comprising:
- instructing a computer processing device to execute a sequence of programmed instructions to cause the computer processing device to:
- measure, using an electronic portal imaging device, radiation scattered relative to a collimator rotation axis of the radiation system;
- calculate an asymmetry value from the measured scattered radiation, the asymmetry value representing a measure of radiation beam symmetry relative to the collimator rotation axis;
- determine one or more parameters of the radiation system based on the calculated asymmetry value;
- determine whether the one or more parameters fall within corresponding prescribed ranges;
- and
- adjust one or more control elements of the radiation system affecting the one or more parameters based on a result of the determining,
- wherein the radiation is scattered by one of a scatter probe positioned in the radiation field or a scatter probe simulated by a scattering aperture created by an off-axis field generated in the radiation system, the off-axis field being generated by positioning at least an element of a collimator of the radiation system so as to be offset relative to the collimator rotation axis,
- wherein the measuring of the scattered radiation by the scatter probe comprises:
- moving the scatter probe from a first location to a second, symmetric location around the collimator rotation axis;
- irradiating the scatter probe at the first and second locations with radiation;
- and
- measuring radiation scattered by the scatter probe at the first location and radiation scattered by the scatter probe at the second location using the electronic portal imaging device, and
- wherein the measuring of the scattered radiation by the simulated scatter probe comprises:
- moving the scattering aperture created by the off-axis field from a first location to a second, symmetric location in the radiation field by rotating the collimator around the collimator rotation axis,
- irradiating the scattering aperture at the first and second locations with radiation;
- and
- measuring radiation scattered by the scattering aperture at the first location and radiation scattered by the scattering aperture at the second location using the electronic portal imaging device.
15 more elements
A method for calibrating a radiation system, comprising:
- measuring, using an electronic portal imaging device, radiation scattered relative to an axis of the radiation system;
- calculating an asymmetry value from the measured scattered radiation, the asymmetry value representing a measure of radiation beam symmetry relative to the axis;
- determining one or more parameters of the radiation system based on the calculated asymmetry value;
- determining whether the one or more parameters fall within corresponding prescribed ranges;
- and
- adjusting one or more control elements of the radiation system affecting the one or more parameters based on a result of the determining,
- wherein the radiation is scattered by a scatter probe simulated by a scattering aperture created by an off-axis field generated in the radiation system.
4 more elements
Dependencies are inferred from the claim text.