A method of beam angle optimization for an IMRT radiotherapy treatment includes providing a patient model having one or more regions of interest (ROIs), defining a delivery coordinate space (DCS), for each ROI, solving an adjoint transport to obtain an adjoint solution field from the ROI, for each vertex in the DCS, evaluating an adjoint photon fluence by performing ray tracing of the adjoint solution field, evaluating a dose of the ROI using the adjoint photon fluence, for each vertex in the DCS, evaluating a respective beam's eye view (BEV) score of each pixel of a BEV plane using the doses of the one or more ROIs, determining one or more BEV regions in the BEV plane based on the BEV scores, determining a BEV region connectivity manifold based on the BEV regions, and determining a set of IMRT fields based on the BEV region connectivity manifold.

A radiation therapy apparatus of an embodiment allows radiation to be applied while rotating a gantry and controls irradiation and stop of the radiation during the rotation of the gantry based on respiration of a treatment subject, and includes processing circuitry. The processing circuitry detects the respiration of the treatment subject. The processing circuitry predicts an administration dose based on a respiratory phase range in which the radiation is applied in the respiration of the treatment subject, and changes at least one or both of a dose rate of the radiation to be applied to the treatment subject and a rotation speed of the gantry so that the administration dose reaches a target dose. The processing circuitry performs control according to the change with respect to at least one or both of the dose rate of the radiation and the rotation speed of the gantry.

Systems and methods for synchronous motion optimization of device of moving components are provided. The methods may include obtaining positions of multiple components of a system; determining, based on the positions, a velocity of each component at each position; determining, based on the velocity of each component, a minimum duration for each component to traverse each segment between two sequential positions; determining, based on the minimum duration for each component to traverse each segment, an optimized duration corresponding to each segment; and determining, based on the optimized duration corresponding to each segment, motion parameters of each component in each segment, the motion parameters of each component in each segment forming the control plan of the system.

An example particle therapy system includes a particle accelerator to output a particle beam having a spot size; a scanning system for the particle accelerator to scan the particle beam in two dimensions across at least part of a treatment area of an irradiation target; and an adaptive aperture between the scanning system and the irradiation target. The adaptive aperture includes structures that are movable relative to the irradiation target to approximate a shape to trim part of the treatment area. The part of the treatment area has a size that is based on an area of the spot size.

A non-transitory computer readable medium (26) stores instructions executable by at least one electronic processor (20) to perform a method (100, 200) of identifying possible arc segments for removal in a modulated arc therapy plan. The method includes: iteratively optimizing a modulated arc therapy plan for an initial arc segment; and computing a geometric freedom (GF) metric for each control point (CP) of the initial arc segment.

Provided are a method and apparatus for adjusting dose rates, a computer device, and a storage medium. In the method, an output pulse frequency is determined based on a current actual dose, a current target dose, and a current pulse frequency, and then a dose rate of a radiation beam emitted by radiation source equipment is updated based on the output pulse frequency. The current pulse frequency is indicative of the dose rate of the radiation beam emitted by the radiation source equipment, the current actual dose is an actually received dose of the radiation beam for a tumor target region, and the current target dose is an expected dose of the radiation beam for the tumor target region.

A method of measuring a rotational position of an assembly with circumferential ferromagnetic teeth includes applying an excitation signal for a cycle to an actuator, the cycle causing a first rotational displacement of a first ferromagnetic tooth from a first rotational position to a second rotational position and a second rotational displacement of a second ferromagnetic tooth from the second rotational position to a third rotational position. The method further includes measuring a plurality of first signal outputs from a magnetoresistive sensor during the cycle; determining one or more signal offset values based on the plurality of first signal outputs; applying the signal excitation for a portion of a second cycle to the actuator; measuring second signal outputs from the magnetoresistive sensor; generating corrected signals by modifying the second signal outputs with the signal offset values; and, based on the corrected signals, determining a rotational position of the assembly.

A multileaf collimator includes a plurality of movable leaves for shaping a radiotherapy beam, wherein each leaf is independently movable in a same linear travel direction. Each leaf includes a linear array of magnets disposed on a measurement surface of the leaf and an array of magnetoresistive sensors that is disposed proximate the measurement surfaces of the leaves.

A radiotherapy system includes an X-ray target configured to convert an incident electron beam into a therapeutic X-ray beam, a purging magnet configured to redirect unwanted particles emitted from the X-ray target away from the therapeutic X-ray beam, and a particle collector configured to absorb the unwanted particles subsequent to redirection by the purging magnet. The particle collector may be configured to dissipate at least 50% of the energy of the incident electron beam.

A multi-layer multi-leaf collimation system includes at least a two layers of collimation leaves. The first multi-leaf collimator layer is configured to primarily perform a first function to affect a radiation beam traveling from a radiation source to a target and a second multi-leaf collimator layer is configured to primarily perform a second function, different from the first function, to affect the radiation beam for the administration of a treatment plan.