Abstract:
Techniques for producing segmentation with privacy are provided. The techniques include receiving a medical image; processing the medical image with a student machine learning model to estimate radiotherapy plan parameters, the student machine learning model being trained to establish a relationship between a plurality of public training medical images and corresponding radiotherapy plan parameters, the radiotherapy plan parameters of the plurality of public training medical images being generated by aggregating a plurality of radiotherapy plan parameter estimates produced by: processing the plurality of public training medical images with a plurality of teacher machine learning models to generate sets of radiotherapy plan parameter estimates; and reducing respective dimensions of the sets of radiotherapy plan parameter estimates or medical images, the radiotherapy plan parameters of the plurality of public training medical images being perturbed in accordance with privacy criteria; and generating a radiotherapy treatment plan based on the estimated radiotherapy plan parameters.
Abstract:
The present invention relates to the field of stereotactical surgery. In particular, the invention concerns a stereotactic surgical instrument for use in stereotactical therapy and surgery and a coupling mechanism for such an instrument. The stereotactic surgical instrument includes a semi-circular arc part (28) and a head frame (24), wherein the head frame is arranged for fixation to a head of a patient by means of pins or screws, wherein the arc part comprises coupling members (30) shaped as rings arranged at a fixed distance from each other for attaching and locking the arc part to the head frame, wherein the head frame comprises support members formed as rings for receiving corresponding coupling members, wherein each coupling member includes a pivotable clamp element arranged to partly surround a respective support member circumferentially when the arc part is coupled to the head frame, and wherein the coupling members includes locking elements arranged to receive a tip portion of the respective clamp element and adjustable locking knobs for tightening and locking respective coupling member to respective support member.
Abstract:
The present invention relates to the field of radiation therapy. In particular, the invention concerns a method of calibrating a positioning system in a radiation therapy system comprising a radiation therapy unit having a fixed radiation focus. The method comprises the steps of irradiating a calibration tool comprising at least one reference object, capturing at least one two-dimensional image including cross- sectional representations of reference objects of the calibration tool and determining image coordinates of the representation of each reference object. Based on the reference objects image coordinates, positions of the reference objects in the stereotactic coordinate system relative to an origin of the calibration tool and the position of the origin of the calibration tool relative to the imaging unit, a position difference between the position of the calibration tool in the stereotactic coordinate system and a position of the calibration tool in an imaging system coordinate system including a translational and rotational position difference is calculated.
Abstract:
Systems and methods for Image-Guided Radiation Therapy (IGRT), particularly but not exclusively when practised with a magnetic resonance imaging (MRI) system, which utilises an iterative approach which adjusts a treatment plan based on inter- or intra-fraction images to significantly improve the accuracy of the radiation delivered during the overall treatment. The prescribed dose of radiotherapeutic radiation is mapped onto the patient's anatomy using an image acquired of the region which is to be the target for radiotherapeutic radiation. Following beam-angle-optimisation, fluence optimisation and segmentation, the efficiency of delivery of each segment is determined using an objective function, and the segments ranked according to their efficiency. The plan proceeds with the choice of the most efficient segment (or segments) to be delivered first. When this radiation has been delivered, having been tracked to establish its distribution, this delivered distribution can be subtracted from the original prescribed dose and the process repeated so that the delivered radiation gradually converges on the original prescribed dose.
Abstract:
Embodiments of the invention provide systems and methods for evaluating treatment parameters for a patient undergoing radiotherapy. The method includes the step of generating a portal dosimetry image showing differences between a planning image obtained prior to a treatment session and a portal image obtained during the treatment session. A database of prior portal dosimetry results is accessed, and a processor is used to perform a similarity measurement between the portal dosimetry image and the prior portal dosimetry results. Based on the similarity measurement, the system determines whether radiation was delivered as planned during the treatment session.
Abstract:
The co-registration error can be estimated by performing a number of additional iterative co-registrations, each iteration having a starting point dictated by the found co-registration transformation, and using a set of initial parameters different to that of the co-registration being tested. The spread in the resulting co-registrations can then be used as the estimate of the co-registration error. The variations in the set of initial parameters can include (i) the candidate transformation which the iteration uses as its starting point, adopting starting points that are offset from the co-registration being tested, (ii) the sample points used for the mutual information metric (or whichever metric is used to optimise the transformation), and (iii) the region-of-interest that is selected. Ideally, all three are varied to some extent within the plurality of additional co-registrations that are performed, and an average value is taken.
Abstract:
The present invention introduces a method, device and a computer program for removing artifacts present in individual channels of a multichannel measurement device. At first, a basis is generated defining an n-dimensional subspace of the N-dimensional signal space, where n is smaller than N, where using in the definition of the n-dimensional basis a physical model of a Signal Space Separation method, or a statistical model based on the statistics of recorded N-dimensional signals. Thereafter, a combined (n+m) - dimensional basis is formed by adding m signal vectors to the n-dimensional basis, each of these m signal vectors representing a signal present only in a single channel of the N-channel device. After this the recorded N-dimensional signal vector is decomposed into n+m components in the combined basis, and finally, components corresponding to the m added vectors in the combined basis are subtracted from the recorded N-dimensional signal vector.
Abstract:
There is a need within the art of radiation therapy for improved systems and methods that enable intra-fraction motion detection with a high degree of accuracy and reliability so as to avoid or at least significantly reduce the risk of undesired damage to surrounding tissue. We therefore disclose a radiotherapy apparatus for treating a patient, incorporating an ionising treatment modality, an ionising investigative source for determining the current patient position so as to guide the ionising treatment modality, a control system for the ionising investigative source, arranged to initiate the commencement of an investigative scan on a periodic basis, and a non-ionising monitoring system that runs continuously with the ionising treatment modality and alerts the control system as to when there appears to have been movement of the patient. In this way, unnecessary ionising investigative scans can be avoided. This reduces the ionising dose that is delivered to the patient whilst still watching for movement and retaining the accuracy of an ionising investigative source such as an x-ray system, computed tomography (CT) system, cone- beam CT apparatus, and the like. The control system initiates an investigative scan after a preset period unless the monitoring system indicates no movement, or if the monitoring system indicates movement. The monitoring system can comprises an ultrasound scanning system, and/or an optical tracking system, and/or a proximity sensor such as an infra-red proximity sensor.
Abstract:
The present invention provides methods and apparatus for the management and provision of radiotherapy, in which values for dosimetric parameters are re-evaluated just prior to treatment (on the basis of the treatment plan as loaded into the radiotherapy apparatus) and during treatment (on the basis of monitored machine parameters). By displaying dosimetric parameters rather than complicated machine parameters, the technician operating the radiotherapy apparatus is able to monitor the dose provided to a patient undergoing therapy. Misadministrations of radiation as a result of corrupted data or corrupted control signals are prevented.
Abstract:
The present invention provides an electron gun (12) comprising a cathode (20), for generating electrons; an anode (22); an intermediate electrode (24), located between the cathode and the anode; and a controller (14). The controller applies an electrical potential to said intermediate electrode, analysing a resultant electrical parameter to determine the integrity of said intermediate electrode; and controls the electron gun to emit a pulse of electrons.