Abstract: An example electrostatic machine includes a rotor plate and an adjacent stator plate, where the rotor plate or the stator plate includes a coupled bearing. The other one of the rotor plate or the adjacent stator plate includes a race radially aligned with the coupled bearing. The coupled bearing has a width with a first contact point on the first one of the rotor plate or stator plate and a second contact point on the race on the other one of the rotor plate or stator plate, where the coupled bearing is sized to maintain a minimum separation distance between the rotor plate and the stator plate.

Abstract: A system and method of delivering a radiation therapy treatment plan to a patient. The treatment plan is delivered using a radiation therapy system including a moveable support for supporting a patient, a gantry moveable relative to the support and supporting a radiation source and multi-leaf collimator for modulating the radiation source. The support and gantry are moved during delivery of the treatment plan.

Abstract: A system for and method of delivering radiation therapy to a moving region of interest is disclosed. The method, in one implementation, includes the acts of generating a plurality of treatment plans for providing radiation therapy, delivering radiation therapy to the patient following one of the plurality of treatment plans, monitoring the patient while providing radiation therapy, and changing the treatment plan based at least in part on monitoring the patient.

Abstract: A method of contoured-anatomy dose repositioning (CADR) as a means to automatically reposition a patient to better recover the planned dose distribution without reoptimizinq the treatment plan. CADR utilizes planning CT images, the planned dose distribution, and on-line images for repositioning dose distribution on a given day. Contours are also placed upon the images using manual, automatic, template-based, or other techniques. CADR then optimizes the rigid-body repositioning of the patient so that the daily dose distribution closely matches the planned dose distribution.

Abstract: A radiation therapy treatment system and method of treating a patient with radiation. The system integrates positioning of the patient, treatment planning, and delivery of the plan. As a result of the integration of imaging capabilities into the treatment apparatus, and efficient processes for contouring and planning, a patient can be treated in approximately 20 minutes or less. The method includes acquiring image data from the patient, defining a target region with one or more predefined shapes, generating a treatment plan based on the defined target region, and delivering radiation to the target region.

Abstract: A radiation treatment system and method of commissioning the system, the system including a gantry, a radiation source operable to produce a beam of radiation, and a measurement device. The measurement device is physically connected to the gantry, and includes a multi-dimensional scanning arm, and a detector. The method includes generating radiation from the radiation source, passing the radiation through an attenuation block, and receiving radiation with the measurement device. The measurement device is positioned such that it is not in contact with water. Data is generated from the radiation received and the system is commissioned using the generated data to match system characteristics to a previously defined standard.

Abstract: System and method of evaluating quality assurance criteria related to the delivery of a radiation therapy treatment plan. The method includes the acts of acquiring image data of a patient, generating a treatment plan for the patient based at least in part on the image data, the treatment plan including a calculated radiation dose to be delivered to the patient, acquiring an on-line image of the patient in substantially a treatment position, delivering at least a portion of the calculated radiation dose to the patient, monitoring quality assurance criteria related to the delivery of the treatment plan, calculating the radiation dose received by the patient, and determining whether delivery of the treatment plan occurred as intended based on the quality assurance criteria and the radiation dose received by the patient.

Abstract: A system and method of defining a new region of interest for an existing region of interest using a dose volume histogram. The method includes the acts of generating a dose volume histogram of radiation dose for a pre-existing region of interest, selecting a subset of the dose volume histogram, and defining a new region of interest that corresponds to the selected subset of the dose volume histogram.

Abstract: A system and method of adapting a radiation therapy treatment plan. The method includes the acts of preparing a treatment plan for a patient, acquiring images of the patient, performing deformable registration of the images, acquiring data relating to a radiation dose delivered to the patient, applying a biological model relating the radiation dose delivered and a patient effect, and adapting the radiation therapy treatment plan based on the deformable registration and the biological model.

Abstract: A high efficiency radiation detector employs longitudinally extending converter elements receiving longitudinally propagating radiation to produce high-energetic electrons received by detector structures in interstitial spaces. The secondary electron generation in this architecture allows great freedom in selection of converter materials and thickness. A variety of detector mechanisms may be used including ionization-type detectors or scintillation-type detector.

Abstract: The present invention provides a system and method of using current but incomplete data to prepare an approximated complete image of a patient potentially undergoing radiation therapy. A limited patient image, such as that obtained from a CT scan is fused with a complete image of the same area using image registration techniques. The fused image is converted to sinogram data. This data is compared to sinogram data corresponding to the limited patient image to determine what data exists beyond the scope of the limited sinogram. Any additional data is added to the limited data sinogram to obtain a complete sinogram. This is reconstructed into an image that approximates the complete image that would have been taken at the time the limited image was obtained.

Abstract: The present invention provides methods of using current but incomplete data to prepare an approximated complete image of a patient potentially undergoing radiation therapy. A complete image of the patient is fused or aligned with a limited patient image using image registration techniques. The aligned image is converted to sinogram data. This sinogram data is compared to sinogram data corresponding to the limited patient image to determine what data exists beyond the scope of the limited sinogram. Any additional data is added to the limited data sinogram to obtain a complete sinogram. This complete sinogram is then reconstructed into an image that approximates the complete image that would have been taken at the time the limited image was obtained.

Abstract: A high efficiency radiation detector employs longitudinally extending converter elements receiving longitudinally propagating radiation to produce high-energetic electrons received by detector structures in interstitial spaces. The secondary electron generation in this architecture allows great freedom in selection of converter materials and thickness. A variety of detector mechanisms may be used including ionization-type detectors or scintillation-type detector.

Abstract: A method of compensating for unexpected changes in the size, shape, and/or position of a patient in the delivery of radiation therapy. An image of a patient is used to prepare a treatment plan for the irradiation of a tumor or the like, shown in the image. A second image of a patient includes a visual representation of the tumor and sensitive structures wherein any combination of the size, shape, or position of the tumor or sensitive structures is different from any combination of the size, shape, or position of the visual representation of the tumor or sensitive structures in said first image. The radiation treatment is adjusted to more closely conform the treatment plan to the new size, shape, or position of the tumor as shown in said second image. This adjustment can occur before, during, or after the radiation delivery and can be used to define trade-offs that exist for the delivery.

Abstract: A method of calibration and verification of radiotherapy systems deduced radiation beam fluence profiles from the radiation source from a complete model of an extended radiation phantom together with dose information from a portal imaging device. The improved beam fluence profile characterization made with an iterative modeling which includes scatter effects may be used to compute dose profiles in the extended phantom or a patient who has been previously characterized with a CT scan. Deviations from the expected beam fluence profile can be used to detect patient misregistration.

Abstract: A method for determining a radiation treatment plan for a radiotherapy system providing multiple individual rays of intensity modulated radiation iteratively optimized the fluence of an initial set of such rays by a function that requires knowledge of only the prescribed dose and the dose resulting from the particular ray fluences. In this way, the need to store individual dose distributions of each ray are eliminated.

Abstract: A method of compensating for unexpected changes in the size, shape, and/or position of a patient in the delivery of radiation therapy. An image of a patient is used to prepare a treatment plan for the irradiation of a tumor or the like, shown in the image. A second image of a patient includes a visual representation of the tumor and sensitive structures wherein any combination of the size, shape, or position of the tumor or sensitive structures is different from any combination of the size, shape, or position of the visual representation of the tumor or sensitive structures in said first image. The radiation treatment is adjusted to more closely conform the treatment plan to the new size, shape, or position of the tumor as shown in said second image. This adjustment can occur before, during, or after the radiation delivery and can be used to define trade-offs that exist for the delivery.

Abstract: The present invention provides a system and method of using current but incomplete data to prepare an approximated complete image of a patient potentially undergoing radiation therapy. A limited patient image, such as that obtained from a CT scan is fused with a complete image of the same area using image registration techniques. The fused image is converted to sinogram data. This data is compared to sinogram data corresponding to the limited patient image to determine what data exists beyond the scope of the limited sinogram. Any additional data is added to the limited data sinogram to obtain a complete sinogram. This is reconstructed into an image that approximates the complete image that would have been taken at the time the limited image was obtained.

Abstract: In radiotherapy, a high quality imaging array may be placed after the patient and opposite the radiation source to be used during radiation treatment to verify operation of a shutter system or similar device and/or to compute dose delivered to the patient. A model of the patient may be used and inverted in order to estimate values of energy fluence prior to absorption by the patient and overlapping of the various radiation beams passing through the patient. A test pattern of shutter excitation to illuminate a single ray at a time provides a simple method of obtaining the necessary model. The dose from this test pattern may be subtracted from the subsequent radiation treatment so as to provide limited or no increase in total dose to the patient.

Abstract: A method of calibration and verification of radiotherapy systems deduced radiation beam fluence profiles from the radiation source from a complete model of an extended radiation phantom together with dose information from a portal imaging device. The improved beam fluence profile characterization made with an iterative modeling which includes scatter effects may be used to compute dose profiles in the extended phantom or a patient who has been previously characterized with a CT scan. Deviations from the expected beam fluence profile can be used to detect patient misregistration.