A61N2005/1076

RADIATION BEAM ALIGNMENT FOR MEDICAL LINEAR ACCELERATORS
20220355131 · 2022-11-10 · ·

Radiation beam alignment for a LINAC including (1) for each beam alignment parameter value of a set: (a) with a beam alignment parameter of a LINAC set to the beam alignment parameter value, using a gantry to generate a radiation beam; (b) using an imaging device to acquire a radiation transmission image indicative of a radiation field of the radiation beam after passing by a radiation opaque marker; (c) determining a location of a beam axis of the radiation beam and a center of a shadow of the marker based on the radiation transmission image; and (d) determining a target-to-beam-axis distance between the location of the beam axis and the center of the shadow of the radiation opaque marker; and (2) determining an optimum beam alignment parameter value based on the beam alignment parameter values and the target-to-beam-axis distances determined with the LINAC set to the beam alignment parameter values.

Automated detection and identification of phantoms

A phantom, phantom system, and method of phantom identification include a first material that forms a phantom. A phantom identifier includes at least one unit marker. The at least one unit marker identifies a physical characteristic of the phantom. In a method of phantom identification, an image of the phantom is obtained that includes the phantom identifier. The at least one unit marker is identified, the at least one unit marker encodes a value representative of a physical characteristic of the phantom.

METHOD TO DETERMINE A PATIENT DOSE DISTRIBUTION AND CORRESPONDING RADIATION DOSIMETRY APPARATUS

In a method to determine a patient (radiation) dose distribution (13), it is provided to calculate, from a measured signal (7) of a detector (6) placed behind a region of interest, a dose distribution (11) for a patient-shaped water equivalent phantom (12) and to compute from this a patient dose distribution (13) that takes into account inhomogeneities of a matter distribution of the patient (4).

Method of calibrating a patient monitoring system for use with a radiotherapy treatment apparatus

A method of calibrating a monitoring system (10,14) is described in which a calibration phantom (70) is located with its center located approximately at the isocenter of a treatment room through which a treatment apparatus (16) is arranged to direct radiation, wherein the surface of the calibration phantom (70) closest to an image capture device (72) of the monitoring system (10,14) is inclined approximately 45° relative to the camera plane of an image capture device of the monitoring system. Images of the calibration phantom (70) are then captured using the image capture device (72) and the images are processed to generate a model of the imaged surface of the calibration phantom. The generated model of the imaged surface of the calibration phantom (70) is then utilized to identify the relative location of the center of the calibration phantom (70) and the camera plane of the image capture device (72) which is then utilized to determine the relative location of the camera plane of the image capture device and the isocenter of a treatment room.

CALIBRATION PHANTOM FOR RADIOTHERAPHY
20230036916 · 2023-02-02 ·

A calibration phantom for radiometric characterization and/or radiotherapy dose calculation of a subject is provided, which includes an ellipsoid base having a primary volume defining a plurality of cylindrical voids, each of said cylindrical voids configured to receive a cylindrical insert having a diameter, wherein the ellipsoid base, the primary volume, and each of said inserts are formed from a tissue substitution material independently selected to approximate a radiological property of an anatomical feature of the subject to which the ellipsoid base, the primary volume, and each of said inserts corresponds, wherein the radiological property of the tissue substitution material, the diameter of each of said inserts, and a location of each of said inserts within the ellipsoid base are selected to mimic beam hardening upon exposure of the calibration phantom to a radiation beam. Optionally, one or more peripheral rings are disposed concentrically about the ellipsoid base. Methods of mitigating off-target radiation exposure improving certainty of a radiotherapeutic dose delivered to a human subject using the calibration phantom are also provided.

Method for EPID-based verification, correction and minimization of the isocenter of a radiotherapy device
11607564 · 2023-03-21 · ·

A method for EPID-based verification, correction and minimization of the isocenter of a radiotherapy device includes the following: Positioning a measurement body; applying an irradiation field; capturing a common dose image of the measurement body; creating a dose profile on the basis of the captured dose image; determining an inflection point in a plot of the dose profile; linking positions of the inflection points to bodily limits of the measurement body; determining position of a center point of the measurement body relative to an EPID-center; determining a differential vector from a deviation in position of the center point of the measurement body from the EPID-center and from a deviation in position of the field center point of the irradiation field from the EPID-center; and correcting the current radiological isocenter.

Automated 3D dosimetry
11607566 · 2023-03-21 ·

An improved hodoscope radiation detector includes a cone filled with a plastic medium that is closer to the density of water (“tissue equivalent”) than air. The medium may have the following properties: 1) Highly transparent with little optical distortion 2) Produces light along the path of incident radiation (x-rays, protons, and ions of heavier weight like carbon, helium, etc.—also called hadrons) 3) Moldable and/or machinable (i.e., not a hard crystal) 4) Homogeneous—evenly distributed density. This medium can fill the cone completely or only a section of the cone (i.e., frustum) or a subsection of the cone such as a cylinder.

Phantom

Embodiments of the present invention provide a phantom and radiation detection system (100) comprising a vessel for containing a tissue equivalent liquid and adapted to pass a beam of test radiation into the vessel (110), a detector (140) adapted to determine the intensity of the beam of test radiation, the detector (140) being supported within the vessel (110) and movable therein along an expected path of the beam of test radiation, wherein the detector (140) is a 2-dimensional detector adapted to determine the spatial intensity and energy deposition of the beam.

PHANTOM SYSTEMS FOR RADIATION DOSIMETRY

A phantom system is disclosed that includes a phantom and at least one removable phantom attachment configured to be attached to the phantom so that the phantom system may have an orientation, location and/or anthropomorphic feature identifiable to an imaging device.

Method to Register an Optical Tracking System with a Particle Detector System

A novel method and a related system are configured to place measured trajectories into a voxel space, which moves with respect to a particle detector system. The trajectories are measured in a detector reference frame. The voxel space, typically fixed with respect to the object being imaged, is tracked optically with markers and a camera system. A decipherable correlation is established between a set of markers and a set of detector elements. This correlation provides coordinate transformation definitions to place the trajectories into the voxel space in medical imaging, treatment planning, and/or therapeutic applications. The novel method provides a clever process to register an optical tracking system with a particle detector system, which improves quality assurance, accuracy, speed, and operating cost efficiencies of ion, particle, and/or radiation-based imaging, treatment planning, or therapies. This novel method may be utilized in proton imaging, helium imaging, other ion-based imaging, or x-ray imaging.