Abstract: The present invention provides an extendible support mechanism in which a counterbalance system allows extension and retraction of the arm to be carried out with the same level of mechanical effort. Embodiments of the present invention allow the system to be used in a plurality of orientations, and thus the invention has particular utility in the extension and retraction of peripheral devices for radiotherapy systems, where use of a rotatable gantry is common.

Abstract: The present invention relates to the field of radiation therapy and radiation surgery. In particular, the invention relates to devices and methods for stereotactic medical procedures and it provides for repeated accurate positioning (fixation) of a patient, or a part of a patient, for carrying out medical procedures which are done at different times such as fractionated radiation therapy. Specifically, a patient fixation device for fixating a head of a patient relatively a treatment unit as a preparation for treatment or during treatment of the head is provided. The patient fixation device being is adapted to be attached to a stereotactic frame structure connected to the treatment unit.

Abstract: The present invention provides a linear accelerator in which a rotatable conductive vane is employed to vary the electromagnetic coupling between adjacent accelerating cells. The vane is sealed off from the rest of the linear accelerator by an insulating partition, so the pressure around the vane can be higher than in the rest of the accelerator. This greatly simplifies the mechanisms which may be used to control the rotation of the vane, allowing a higher bakeout temperature in manufacture and a higher rate of rotation in use.

Abstract: During treatment by brachytherapy, radiation passes beyond the target volume and delivers radiation dose to adjacent tissue such as the lungs and, especially in the case of treatment of the left breast, to the heart. The heart is particularly vulnerable to radiation; to minimise the dose it receives in such circumstances, we propose an apparatus for treatment by brachytherapy comprising an X-ray source sized for insertion into a patient, a respiration state monitor, and a control apparatus adapted to receive respiration state information from the respiration state monitor and control the output of the X-ray source; the control apparatus being arranged to operate the X-ray source at a first output level when the respiration state monitor indicates a degree of lung inflation above a first preset threshold and operate the X-ray source at a second and lower output level when the respiration state monitor indicates a degree of lung inflation below a second preset threshold.

Abstract: The present invention provides an electron gun comprising a cathode, for generating electrons; an anode; an intermediate electrode, located between the cathode and the anode; and a controller. 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.

Abstract: The present invention discloses a joint structure between the wall elements of a light-weight magnetically shielded room. In the joint structure, the end of the aluminum plate of the element is stepped and its surface roughened. In addition to this, the aluminum plate is coated, for example, with tin to improve the electrical contact. The joint includes ? metal plates which are used to make a magnetic contact between the ? metal plates of the elements. The compression force achieved by means of bolts is transmitted to the joint by means of an aluminum moulding. The non-continuous compression force is balanced over the entire joint area by using presser rubbers. The joint structure is protected by means of supporting profiles which are used to electrically couple the thinner aluminum plate of the sandwich type wall element to the thinner aluminum plate of an adjacent element. The thinner aluminum plate and the supporting profile can also be coated, for example, with tin to improve the contact.

Abstract: The ability to provide a fine resolution variation in the dose rate of radiotherapeutic apparatus would allow delivery times of VMAT and related techniques to be reduced significantly. A radiotherapeutic apparatus is described, comprising a source of radiation able to issue pulses of radiation at a base frequency, and a control apparatus arranged to permit pulses provided these match a pulse pattern chosen to achieve a selected time-averaged power level, the chosen pulse pattern being one selected from a plurality of pulse patterns that include patterns consisting of trains of pulses that include, relative to the base frequency, at least every nth and every mth pulse where n?m and the nth and mth pulses are non-coincident. Essentially, such an apparatus issues a pulse if it is the nth or the mth or the kth (etc) where n, m, k . . . are selectable independently.

Abstract: The present invention relates to a novel manner of measuring DC fields using a multi-channel MEG or MKG measuring instrument; and on the other hand, to a manner of eliminating from the measurement result the interference signals caused by the DC currents. The invention combines the monitoring system of a testee's movement and the method for motion correction of the measured signals so that the signals produced by the DC currents of a moving testee's are visible in the final measurement result as a static signal component in a conventional MEG or MKG measurement. In that case, in the measurement, it is not necessary to beforehand prepare oneself for measuring the DC fields.

Abstract: The present invention relates to a frame for attaching to a patient. The present invention also relates to a stereoguide and a member for attaching to a patient. The present invention also relates to a method for manufacturing the frame, member and stereoguide of the present invention. The frame, member and stereoguide are constructed from a composite material comprising a matrix material and electromagnetically inert fibers.

Abstract: A reference image is used to calibrate a subsequent image, such as one obtained during therapy. A number of local histograms are prepared for each image, a transformation is identified that transforms the histograms to be substantially the same and is applied to voxels in the subsequent image. Changes between the reference and subsequent images such as the movement of internal structures will be preserved since the method compares local histograms and this corrects intensities, not shapes. Gently varying artifacts such as the cup artifact will be substantially eliminated. The volume image thus derived can then be used for treatment planning.

Abstract: The present invention relates to a device for fixation to a patient during neurological diagnosis, therapy or surgery, in particular during MRI diagnosis. The device comprises at least one fixation pin being made of a non-magnetic, electrically conductive material for fixation to a patient, and at least one pin support member for supporting said fixation pin. An insulation means is arranged so as to restrict the electrical coupling between said pin support member and fixation pin. Said insulation means is sleeve shaped and arranged to at least partly surround said fixation pin. The invention also relates to an insulation means, a pin support member and to a method for assembling a fixation device.

Abstract: The present invention provides a method and an apparatus for reconstructing images from data acquired during radiotherapy. The approach is based on summing the imaging data acquired while both therapeutic and imaging source are active, with that acquired when only the therapeutic source is active. Further correction of the summed data can lead to reconstructed images of excellent quality.

Abstract: A patient can be taken to the operating theatre where a measurement arm can be used to locate fiducial markers relative to a fixed substrate. As a result, the location of the region of interest is known. An instrument guide, adapted to constrain movement of an instrument thereon, can then be positioned at a suitable location, and its location checked by way of the measurement arm. A computing means connected to the measurement arm so as to receive information as to the location of the tip can be programmed to determine a desired necessary movement of the guide in order to locate the instrument at a desired location relative to the region of interest. The guide can then be moved in a controlled and accurate manner from its initial position to an accurately determined correct position.

Abstract: The present invention provides a radiotherapy apparatus for applying therapeutic radiation to a target region of a patient, comprising a patient support, a source of radiation, a collimator comprising a plurality of leaves, a sensing system and control circuitry. The position of a target region is determined and resolved into two components orthogonal to the radiation beam axis. One component is assigned to the patient support, and the other to the collimator leaves, such that movement of the target region is compensated for and the radiation beam intersects is correctly targeted.

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: Realtime beam shape adjustment in response to (for example) online CT scanning of a patient during treatment is assisted by the radiotherapy apparatus comprising a source adapted to emit a beam of therapeutic radiation, a collimator for delimiting the radiation beam, the collimator comprising a plurality of leaves arranged alongside each other and be moveable longitudinally so that the tips of the leaves define a variable edge of the collimator, the leaves being mounted on a support that is moveable laterally with respect to the leaves. In this way, movements of the tumor that are perpendicular to the direction of leaf motion can be accommodated by simply moving the collimator bodily so as to accommodate this. It is preferred that the apparatus also includes a control means adapted to receive information as to the location of the target volume, and, on the basis of that information, control the longitudinal positions of the leaves and the lateral position of the support.

Abstract: An approach to radiotherapy is disclosed which allows the therapeutic beam to be more accurately directed towards a target region. Instead of stopping acquiring images during treatment, the system continues to acquire images as treatment is ongoing. This ongoing pipeline of images is used to update the previously created 3D reconstructions of each breathing phase. Thus the position of the target region can also be updated. The surrogate is recorded simultaneously with the image acquisition although it is not used to determine the breathing phase. As new images are used to update the 3D reconstructions of each breathing phase the values of the surrogate associated with that phase are also updated. This means that the correlation with the surrogate can also continue to be evaluated, and the correlation refined, thus improving the ability of the system to track the motion of the target.

Abstract: This invention relates to a fixation device for immobilizing a head of a patient relative a treatment unit or medical device during treatment of the head. The fixation device is provided with an interface unit adapted to be fixated in relation to an adaptor unit for connection to the treatment unit, or to a frame for connection to the medical device. Furthermore, the fixation device is further provided with a sliding plate being slidable in relation to said interface unit in an xz-plane of a coordinate system. The system is a Cartesian coordinate system defined by three orthogonal axis having an x-axis extending in the medial-lateral direction of the patient, an y-axis extending in the anterior-posterior direction, and a z-axis extending in the cranial-caudal direction.

Abstract: The present invention relates to the field of radiation therapy. In particular, the relates to a system for measuring the position of a head of a patient during neurological diagnosis, therapy or surgery, in particular during radiation therapy relatively a frame adapted to be fixated to a radiation therapy unit. The invention also relates to a head cap and a measurement tool for use in such a system, and to a method measuring the position of a head of a patient by means of a system mentioned above during neurological diagnosis, therapy or surgery, in particular during radiation therapy relatively a frame adapted to be fixated to a radiation therapy unit.

Abstract: A radiotherapy apparatus comprises a means for producing a beam of radiation directed along a beam axis and having a width in first and second directions transverse to the beam axis, a multi-leaf collimator for selectively limiting the width of the beam in at least the first direction, a block collimator for selectively limiting the width of the beam in at least the second direction, the block collimator comprising a diaphragm moveable into and out of the beam and having a thickness in the direction of the beam axis that varies. The diaphragm can have a front edge of greater thickness than at least one region behind the front edge. It can also have a spine region extending from a rear part thereof towards the front edge that is greater thickness than at least one region displaced laterally with respect thereto. Together, these can cover the areas that will not be fully shadowed by a dynamically moving MLC.