Abstract: A system includes presentation of a view of portions of structures that would be intercepted by a path of radiation during radiation treatment from a perspective of a location. The radiation enters an entry surface of a radiation-focusing lens, exits an exit surface of the radiation-focusing lens, and is substantially focused on a focal area. The location is located such that a plane perpendicular to an axis of the path, intercepting the exit surface, and positioned between the entry surface and the focal area would be located between the location and the lens.

Abstract: A method for converting a source intensity map into a target intensity map having a geometry compatible with a desired multi-leaf collimator configuration. The source intensity map and the target intensity map each have a geometry defining sampling points of cells within the maps. The method includes defining a field on an object for radiation delivery. The field includes a plurality of cells defining the source intensity map, each of the cells having a treatment intensity level. An intermediate intensity map geometry is created such that the intermediate map contains sampling points of the source intensity map and the target intensity map. The method further includes defining treatment intensity levels for cells of the intermediate map and calculating treatment intensity levels for cells of the target intensity map based on the intensity level of the intermediate map cells.

Abstract: A method for delivering radiation from radiation source to a treatment area. A multi-leaf collimator is positioned between the radiation source and the treatment area to block a portion of the radiation and to define a first treatment field. The collimator is positioned with leaves of the collimator extending longitudinally in a first direction. The collimator is first moved through an arc while delivering radiation through the first treatment field to the treatment area. The multi-leaf collimator is rotated about a central axis extending generally perpendicular to a plane containing at least a portion of the leaves such that the leaves define a second treatment field. The multi-leaf collimator is then moved through a second arc while delivering radiation through the second treatment field to the treatment area.

Abstract: A method for delivering radiation from a radiation source to treatment a area utilizing a multi-leaf collimator. The method includes positioning the multi-leaf collimator between the radiation source and the object to block a portion of the radiation. The leaves of the multi-leaf collimator are generally located within a plane and extend longitudinally along a first axis. The leaves are positioned to define a first treatment field. The method further includes delivering radiation to the first treatment field and rotating the multi-leaf collimator about a central axis extending generally perpendicular to the leaf plane.

Abstract: A system and method of the present invention for controlling radiation delivery from a radiation source to an object are disclosed. The method generally includes defining a field on the object for radiation delivery. The field includes a plurality of cells, each having a defined treatment intensity level. The cells are grouped to form a matrix having at least one dimension approximately equal to a width of a collimator leaf capable of blocking radiation emitted from the radiation source. The method further includes decomposing the matrix into orthogonal matrices and optimizing delivery of the radiation by selecting a combination of orthogonal matrices to minimize junction effects.

Abstract: A system includes presentation of a view of portions of structures that would be intercepted by a path of radiation during radiation treatment from a perspective of a location. The radiation enters an entry surface of a radiation-focusing lens, exits an exit surface of the radiation-focusing lens, and is substantially focused on a focal area. The location is located such that a plane perpendicular to an axis of the path, intercepting the exit surface, and positioned between the entry surface and the focal area would be located between the location and the lens.

Abstract: A method for defining an extended field area of an intensity map for use in delivering radiation from a radiation source to an object with a multi-leaf collimator is disclosed. The multi-leaf collimator includes a plurality of leaves operable to travel in a first direction and rotatable such that the leaves are operable to travel in a second direction extending generally orthogonal to the first direction. The method includes defining a central square area having dimensions approximately equal to two times an over travel margin of the multi-leaf collimator and defining four edge margins each extending from a side of the central square and having dimensions approximately equal to two times an over travel margin of the multi-leaf collimator along an edge adjacent to the central square and half the number of leaves within the multi-leaf collimator times leaf width minus half the central square dimension.

Abstract: A method for converting a source intensity map into a target intensity map having a geometry compatible with a desired multi-leaf collimator configuration. The source intensity map and the target intensity map each have a geometry defining sampling points of cells within the maps. The method includes defining a field on an object for radiation delivery. The field includes a plurality of cells defining the source intensity map, each of the cells having a treatment intensity level. An intermediate intensity map geometry is created such that the intermediate map contains sampling points of the source intensity map and the target intensity map. The method further includes defining treatment intensity levels for cells of the intermediate map and calculating treatment intensity levels for cells of the target intensity map based on the intensity level of the intermediate map cells.

Abstract: A method for defining an extended field area of an intensity map for use in delivering radiation from a radiation source to an object with a multi-leaf collimator is disclosed. The multi-leaf collimator includes a plurality of leaves operable to travel in a first direction and rotatable such that the leaves are operable to travel in a second direction extending generally orthogonal to the first direction. The method includes defining a central square area having dimensions approximately equal to two times an over travel margin of the multi-leaf collimator and defining four edge margins each extending from a side of the central square and having dimensions approximately equal to two times an over travel margin of the multi-leaf collimator along an edge adjacent to the central square and half the number of leaves within the multi-leaf collimator times leaf width minus half the central square dimension.

Abstract: A system and method of the present invention for controlling radiation delivery from a radiation source to an object are disclosed. The method generally includes defining a field on the object for radiation delivery. The field includes a plurality of cells, each having a defined treatment intensity level. The cells are grouped to form a matrix having at least one dimension approximately equal to a width of a collimator leaf capable of blocking radiation emitted from the radiation source. The method further includes decomposing the matrix into orthogonal matrices and optimizing delivery of the radiation by selecting a combination of orthogonal matrices to minimize junction effects.

Abstract: A method for reconstructing an intensity map from segments includes importing a set of segments defining an intensity modulated radiation treatment and analyzing the segments to determine intensity map geometry. The method further includes calculating radiation contributions for cells within the segments and creating a reconstructed intensity map.

Abstract: A method for sequencing treatment fields defined by leaves of a multi-leaf collimator positioned to block radiation from a radiation source and define an opening between the radiation source and a treatment area. The multi-leaf collimator is operable to rotate relative to the treatment area to define a plurality of treatment ports. Each of the ports has at least one treatment field. The method includes ordering the collimator ports based on direction of travel of the collimator relative to the treatment area such that each port has at least one corresponding adjacent port. The method further includes selecting a sequence of treatment fields for each collimator port based on the treatment fields within adjacent ports to optimize delivery of radiation.

Abstract: A method for calculating fluence contributions for radiation delivery from a source to a treatment area through an aperture. The method includes defining a calculation plane located adjacent to said treatment area and a scattering plane located between the radiation source and the calculation plane. A source plane located between the radiation source and scattering plane is also defined. The method further includes ray tracing a point located on the calculation plane to the scattering plane to define a scatter strip and projecting the scatter strip from the scattering plane to the source plane to define a rectangular region. An area integration is performed on the region to determine a fluence value for the rectangular region.

Abstract: A method for defining an intensity map for use in delivering radiation from a radiation source to an object with a multi-leaf collimator is disclosed. The method includes defining a field on the object for radiation delivery. The field includes a plurality of cells each having a defined treatment intensity level. At least a portion of the cells are grouped to form a matrix. The method further includes modifying the treatment intensity level of the cells within the matrix such that horizontal gradients of pairs of rows of the matrix are equal to one another and vertical gradients of pairs of columns of the matrix are equal to one another. A system for defining an intensity map is also disclosed.

Abstract: A method for controlling radiation delivery from a radiation source to a treatment area with a multi-leaf collimator. The method includes dividing the treatment area into a plurality of cells each having a predefined treatment intensity level and defining an edge margin on a portion of the cells. The method further includes defining one or more treatment fields by longitudinally positioning leaves of the multi-leaf collimator to block radiation from some of the cells. The edge margin has an intensity level different than the predeined intensity level of the cell. The longitudinal positions of leaves of the multi-leaf collimator are adjusted so that the leaves cover the edge margins of the cells in at least one of the treatment fields to deliver less radiation to said edge margin than the rest of the cell. A system for controlling radiation delivery to the treatment area from the radiation source is also disclosed.

Abstract: A method for controlling radiation delivery from a radiation source to an object is disclosed. The method includes defining a field on the object for radiation delivery. The field includes a plurality of cells, each cell having a defined treatment intensity level. The cells are grouped to form a matrix having at least one dimension approximately equal to a width of a collimator leaf capable of blocking radiation emitted from the radiation source. The method further includes decomposing the matrix into orthogonal matrices and optimizing delivery of the radiation by selecting the orthogonal matrices having minimum vertical and horizontal gradients when combined with adjacent cells. A system for controlling radiation delivery from a radiation source to an object is also disclosed.

Abstract: The present invention relates to a fast and accurate method for calculating fluence of a calculation plane over a patient. According to an embodiment of the present invention, only a subset of the collimator leaves are analyzed for the fluence calculation, thus reducing the number of calculations required. Additionally, pre-integrated values of scatter strips, associated with each point of the calculation plane, may be referenced in a lookup table. The use of these pre-integrated values allows the avoidance of adding the fluence contribution of each square on the scattering plane. Rather, pre-calculated values of a subset of the scattering plane (scatter strip) may be referenced and combined, thus reducing the number of calculations required for a final scatter contribution to a point on the calculation plane. Further, the thickness of the collimator leaves is considered in the fluence calculation, thus providing a more accurate model for the scatter contributions of points on the scattering plane.

Abstract: Method and system aspects for increasing resolution of a radiotherapy system to achieve virtual fractional monitor unit radiation delivery are described. Included in a method aspect, and system for achieving same, is identification of a desired treatment dose, the desired treatment dose exceeding a resolution of a radiation treatment device. Further included is the development of a schedule of treatment sessions for delivering the desired treatment dose by the radiation treatment device that produces a combined treatment dose equaling the desired treatment dose without exceeding the resolution within each treatment session.

Abstract: The present invention relates to a fast and accurate method for calculating fluence of a calculation plane over a patient. According to an embodiment of the present invention, only a subset of the collimator leaves are analyzed for the fluence calculation, thus reducing the number of calculations required. Additionally, pre-integrated values of scatter strips, associated with each point of the calculation plane, may be referenced in a lookup table. The use of these pre-integrated values allows the avoidance of adding the fluence contribution of each square on the scattering plane. Rather, pre-calculated values of a subset of the scattering plane (scatter strip) may be referenced and combined, thus reducing the number of calculations required for a final scatter contribution to a point on the calculation plane. Further, the thickness of the collimator leaves is considered in the fluence calculation, thus providing a more accurate model for the scatter contributions of points on the scattering plane.

Abstract: The present invention relates to a fast and accurate method for calculating fluence of a calculation plane over a patient. According to an embodiment of the present invention, only a subset of the collimator leaves are analyzed for the fluence calculation, thus reducing the number of calculations required. Additionally, pre-integrated values of scatter strips, associated with each point of the calculation plane, may be referenced in a lookup table. The use of these pre-integrated values allows the avoidance of adding the fluence contribution of each square on the scattering plane. Rather, pre-calculated values of a subset of the scattering plane (scatter strip) may be referenced and combined, thus reducing the number of calculations required for a final scatter contribution to a point on the calculation plane. Further, the thickness of the collimator leaves is considered in the fluence calculation, thus providing a more accurate model for the scatter contributions of points on the scattering plane.