Abstract: Intra-fraction movement of the patient puts at risk sensitive regions that are near to a radiation dose. In a radiotherapy system that delivers a dose as a series of discrete sub-doses, an initial CT scan is performed to determine the patient's position, after which the sub-doses that are directed to regions within a preset distance of a sensitive structure are performed first, while the sub-doses directed to regions that are more remote from a sensitive structure are performed later.

Abstract: An apparatus and method of segmenting an image using scribble segmentation is provided, An image is segmented by constraining the membership value of a subset of image elements, solving a weighted biharmonic equation subject to the constrained membership values wherein the weights are determined from similarities between image elements, and determining the final segmentation based on the membership value of each image element.

Abstract: A radiotherapy apparatus is described which includes a source of radiation for generating a therapeutic beam towards a target region of a patient. A collimation apparatus is configured to act on the beam in a plane transverse to the beam axis. An imaging apparatus is configured to obtain imaging data of the target region. A control apparatus is configured to receive the imaging data from the imaging apparatus and control the collimation apparatus in dependence thereon. The imaging data includes at least one two-dimensional slice image including only a single two-dimensional slice image oriented in any one direction and which includes the target region.

Abstract: Radiotherapy apparatus is disclosed, comprising a radiation source capable of emitting a beam of therapeutic radiation along a beam axis, collimation apparatus for delimiting the beam and comprising (i) a block of sufficient width to extend across the width of the beam, selectively movable into the beam from a first side of the beam axis, and (ii) an array of individually moveable elongate narrow leaves arranged side-by-side in a direction perpendicular to the beam, each being moveable longitudinally into the beam from a second and opposing side of the beam axis, in which there is no array of individually moveable elongate narrow leaves arranged side-by-side in a direction perpendicular to the beam moveable longitudinally into the beam from the first side of the beam axis. Thus, there is in effect a single bank of MLC leaves on one side of the aperture and a block collimator on the other.

Abstract: We provide a radiotherapeutic apparatus comprising a patient support, magnetic coils disposed around the patient support for creating a magnetic field therewithin, a radiation source producing a beam of radiation directed toward the patient support and mounted on a rotatable support thereby to rotate the radiation source around the patient support, a slip ring for conveying electrical power to the radiation source and located around the patient support, including at least one electrical interruption therein. This creates a slip ring in which there is no continuous circumferential path, and one in which the current is therefore forced to take a route via one side or the other.

Abstract: A radiotherapy apparatus is described which includes a patient support, a magnetic resonance imaging (MRI) apparatus for obtaining imaging data of a patient positioned on the patient support, and multiple linear accelerators, each aligned in a plane transverse to the patient support and arranged to provide a therapeutic beam of x-ray radiation to the patient.