Abstract: Embodiments of the present invention provide a method of pre-approving a range of hypothetical spatial variations of the target whilst an initial treatment plan is generated. This allows the treatment plan to be later adapted to account for spatial variations of the target region falling within those pre-approved ranges, without going through time-consuming steps of quality assurance on the adapted plan.

Abstract: The present invention seeks to provide a radiotherapeutic apparatus that mitigates the various problems found in the techniques such as tomotherapy, IMAT, IMRT and the like. It provides a radiotherapeutic apparatus comprising a source of radiation whose output is collimated by a multi-leaf collimator, and a patient support, the source being rotatable around the support and the support being translatable along the axis of rotation, thereby to move the source helically relative to a patient on the support. The leaves of the MLC are preferably oriented orthogonal to the axis of rotation, to simplify computation of the dose distribution. The apparatus thus moves the patient on the patient support system along the axis of rotation, in the longitudinal direction. Thus, the device has an effectively unlimited treatable volume in the longitudinal direction and avoids the limitations of IMAT and IMRT techniques whilst enabling the use of thin MLC leaves to give a high longitudinal resolution.

Abstract: The invention relates to a method for calibrating a measurement tool for measuring the radiation in a radiation system, such as a radiation therapy system. The measurement tool, including a holder and at least one photodiode element, is adapted to be mounted in a positioning unit of the radiation system. The radiation sensitive volume of the photodiode element is embedded in a light transparent coating transparent for, for instance, light in the visible spectrum. Thereby, the position of the sensitive volume can easily be determined or calculated with high accuracy relatively the holder on which the photodiode element is arranged, from which the position of the sensitive volume can be determined or calculated in relation to the positioning unit of the radiation system. The invention also relates to a calibration system for performing the calibration method and a measurement tool for use in the calibration system.

Abstract: The present invention provides a method for updating and optimizing a treatment plan for radiotherapy. An initial treatment plan, calculated using a constraint-driven method, may be updated using a weighted-sum method, where Lagrange multipliers generated in the constraint method are reused as the weights for the weighted sum. This method results in acceptable updated treatment plans that are generated in a small fraction of the time taken to generate an entirely new treatment plan, reducing patient discomfort and ensuring the radiotherapy facility can treat more patients.

Abstract: The present invention therefore provides a method for the analysis of radiographic images, comprising the steps of acquiring a plurality of projection images of a patient, acquiring a surrogate signal indicative of the location of a target structure in the patient, reconstructing a plurality of volumetric images of the patient from the projection images, each volumetric image being reconstructed from projection images having a like breathing phase, identifying the position of the target structure such as a tumour in each volumetric image, associating a surrogate signal with each of the projection images, and determining a relationship between the surrogate signal and the position of the target structure. Multiple projection images having a like breathing phase can be grouped for reconstruction, to provide sufficient numbers for reconstruction. The analysis of the multiple values of the surrogate associated with each breathing phase can be used to determine the mean surrogate value and its variation.

Abstract: A treatment planning apparatus comprises a means for receiving a three dimensional representation of a patient, a means for displaying at least a part of the representation, a means for user-designation of sub-regions of the representation, and a computing means adapted to segment the representation into a region within an anatomical structure and a region outside the anatomical structure on the basis of the locations of the sub-regions and the degree of similarity of voxels to neighbouring voxels in the representation. The treatment planning apparatus preferably further comprises means for designating sub-regions as being inside the structure, means for designating sub-regions as being outside the structure, and/or means for designating sub-regions as being at a border of the structure. In the latter case, we prefer that the size of border sub-regions is adjustable. The computing means can segment the representation by minimising a cost function.

Abstract: An in-line 4D cone beam CT reconstruction algorithm, i.e.

Abstract: A radiotherapy system comprises a patient support, moveable along a translation axis, an imaging apparatus, comprising a first magnetic coil and a second magnetic coil, the first and second magnetic coils having a common central axis parallel to the translation axis, and being displaced from one another along the central axis to form a gap therebetween, the imaging apparatus being configured to obtain an image of a patient on the patient support, a source of radiation mounted on a chassis, the chassis being rotatable about the central axis and the source being adapted to emit a beam of radiation through the gap along a beam axis that intersects with the central axis, a multi-leaf collimator comprising a plurality of elongate leaves movable between at least a withdrawn position in which the leaf lies outside the beam, and an extended position in which the leaf projects across the beam, and a radiation detector mounted to the chassis opposite the source, the radiation detector having a plurality of detector ele

Abstract: A radiotherapy system comprises a patient support, moveable along a translation axis, an imaging apparatus, comprising a first magnetic coil and a second magnetic coil, the first and second magnetic coils having a common central axis parallel to the translation axis, and being displaced from one another along the central axis to form a gap therebetween, the imaging apparatus being configured to obtain an image of a patient on the patient support, a source of radiation mounted on a chassis, the chassis being rotatable about the central axis and the source being adapted to emit a beam of radiation through the gap along a beam axis that intersects with the central axis, a multi-leaf collimator comprising a plurality of elongate leaves movable between at least a withdrawn position in which the leaf lies outside the beam, and an extended position in which the leaf projects across the beam, and a radiation detector mounted to the chassis opposite the source, the radiation detector having a plurality of detector ele

Abstract: A radiotherapy system comprises a patient support, moveable along a translation axis, an imaging apparatus, comprising a first magnetic coil and a second magnetic coil, the first and second magnetic coils having a common central axis parallel to the translation axis, and being displaced from one another along the central axis to form a gap therebetween, the imaging apparatus being configured to obtain an image of a patient on the patient support and a source of radiation mounted on a chassis, the chassis being rotatable about the central axis and the source being adapted to emit a beam of radiation through the gap along a beam axis that intersects with the central axis, the beam having a first extent in a first direction parallel to the central axis, and a second, greater extent in a second direction transverse to the central axis.

Abstract: Radiotherapy apparatus comprises a source of radiation mounted on a chassis, the chassis being rotatable about a rotation axis and the source being adapted to emit a beam of radiation along a beam axis that intersects with the rotation axis; a patient support, moveable along a translation axis; a set of magnetic coils located on either side of the beam, for establishing a magnetic field at the point of intersection, spaced from that point along a first direction; the translation axis, the rotation axis, and the first direction being substantially parallel; and further comprising a multi-leaf collimator fixed in its orientation with respect to the source of radiation, the multi-leaf collimator comprising a plurality of elongate leaves disposed with their longitudinal directions substantially aligned with the first direction and movable in that direction between a withdrawn position in which the leaf lies outside the beam, an extended position in which the leaf projects across the beam and a plurality of interm

Abstract: The invention relates to a stabilizing device adapted to be applied to a stereotactic frame (2, 3), which is provided with fixation pins (4) to allow fixation of the stereotactic frame to a bone (5) of a human or animal body part to be examined or treated, wherein the stabilizing device is adapted to stabilize a fixation pin in relation to the frame. The stabilizing device comprises a stabilizing member (9) which in a first position is provided with a through opening (13), adapted to be applied over the fixation pin in an area between the frame and the body part, and a tensioning member (10) positioned in a second position on a distance from the through opening and being capable of drawing the stabilizing member towards the frame.

Abstract: It is desirable to achieve a co-incident investigative kV source for a therapeutic MV source—a so-called “beams-eye-view” source. It has been suggested that bremsstrahlung radiation from an electron window be employed; we propose a practical structure for achieving this which can switch easily between a therapeutic beam and a beam-eye-view diagnostic beam capable of offering good image resolution. Such a radiation source comprises an electron gun, a pair of targets locatable in the path of a beam produced by the electron gun, one target of the pair being of a material with a lower atomic number than the other, and an electron absorber insertable into and withdrawable from the path of the beam. In a preferred form, the electron gun is within a vacuum chamber, and the pair of targets are located at a boundary of the vacuum chamber. The lower atomic number target can be Nickel and the higher atomic number target Copper and/or Tungsten.

Abstract: A radiotherapeutic apparatus comprises a source able to emit a beam of therapeutic radiation along a beam axis, a multi-leaf collimator arranged to collimate the beam to a desired shape, wherein the source is rotatable about a rotation axis that is substantially orthogonal and intersects with the beam axis thereby to describe an arc around that axis, and further comprises a control means able to control the dose/time rate of the source, the rotation speed of the source, and the multi-leaf collimator position. The control means is arranged to control the source in accordance with a treatment plan over first and second arc-segments such that at least the multi-leaf collimator changes shape at a different rate per degree in the second arc-segment as to the first arc-segment.

Abstract: We propose that during the factory testing of the linac, rather than simply confirming that the beam falls within the permissible ranges set out in the standard, the beam is in fact adjusted towards a standard signature. A new (or existing) linac could then be paired to a new linac, or to an existing linac, such as one that it is to operate alongside or one that it is to replace. Treatment plans would then be transferable between such pairs of linacs. In addition, the standard signature to which the linacs were approximated could be placed towards the centre of the permitted ranges, to produce linacs that were more reliable over the very long term. This requires a linac that has automatically adjustable parameters, so that a suitable programmed computer is able to monitor the output of the linac and adjust its operating parameters.

Abstract: The present invention concerns a method, a system, a measurement tool and computer readable medium for determining a predetermined position of a positioning system in a radiation therapy system comprising a radiation therapy unit relatively a fixed radiation focus point of the radiation therapy unit. The method comprises positioning (73) a diode element, obtaining (75) measurement data at each of a predetermined number of measurement points from a radiation intensity curve, determining (76) a three-dimensional centre coordinate of the obtained coordinates, and determining (76) the predetermined position of a patient positioning unit (20) relatively to a fixed focus point of a radiation unit (10) using the determined three-dimensional centre coordinate.

Abstract: The present invention recognises and eliminates from a biomagnetic measurement signal interferences whose source is disposed in the direct vicinity of an object being measured. The invention utilises the SSS method that can be used to separate from one another the signals associated with the internal and external sources of a set of measurement sensors by calculating two series developments. The sources to be examined in the invention and disposed in the so-called intermediate space produce a component to both of the developments, and can, therefore, be detected by means of an analysis to be performed in a time domain. This division into components can be made using the Principal Component Analysis (PCA), the Independent Component Analysis (ICA) or the Singular Value Decomposition. Finally, the clarified interferences in the intermediate space can be eliminated from the measured signal using, for example, the linear algebraic orthogonal projection.

Abstract: Methods for the registration of images typically assume that there are only two images, an assumption that is not always valid. By using the remaining images to obtain a choice of paths between two selected images, the transformation between the two can be determined with greater accuracy by averaging those paths. When averaging the paths, greater weight can be given to paths whose accuracy is known or reasonably believed to be greatest. Iteration of the process may be possible, where the available computation power is available.

Abstract: For Respiration Correlated Cone Beam CT scanning, we have observed that improvements in the frame rate are in fact undesirable. We therefore propose a radiographic apparatus comprising a beam of radiation and a detector therefor, adapted to obtain a two dimensional image of the beam after passing through a cyclically varying object to be investigated, a processor adapted to review the images and select images at like points in the cycle, and a control means for the beam of radiation adapted to activate the beam periodically. The control means can activate the beam at a frequency of between 0.5 and 5 Hertz, more preferably between 1 and 3 Hertz, which corresponds (roughly) to a frequency that is between 6 and 10 times the frequency of the cyclical variation. It will assist if the selected point of the cycle is an extremity thereof, as the rate of change in these areas is at a minimum. Thus, slight mismatches between the two cycles will then have only a small effect.

Abstract: A reference phantom includes CT-imageable detail together with light-reflective spheres. This item can be placed on a patient table in a known location, following which the diagnostic source can be activated to detect the phantom position relative to the isocentre and camera employed to detect the PSS position. A synthetic image of the phantom can be used for comparison with the CT dataset. This allows improved correlation of the source and the patient support, enable further steps to be taken in enhancing the clinical effectiveness of the apparatus. In-use variations of the isocentre location can be corrected in real time by adjustment of the patient support. Thus, as the isocentre moves, the patient can be moved so as to track the moving isocentre. The linac arm could also be designed differently, as the existing design constraint (that isocentre movement must be limited as far as possible) could potentially be relaxed in order to achieve other aims.