Method for Treatment of Multiple Brain Metastases Based on Iso-Dose Line Prescriptions

Abstract

Disclosed is a computer-implemented method of determining a treatment plan, encompassing acquiring patient image data, acquiring target data describing targets, acquiring position data describing control points which define one or more arcs, and determining target projection data which describes outlines of the target in a beam's-eye view. Margin data is acquired. For the outlines, margins are applied to determine auxiliary outlines. Beam shaping device data is determined describing configurations of the collimator leaves so that irradiation of the auxiliary outlines is enabled. Based on these configurations, the irradiation amount is simulated for voxels of the patient image data. Constraints to be fulfilled by the treatment plan may be set. Configurations of blockings, arc-weights and margins are proposed. Only different combinations of these parameters are proposed while additional possible parameters are neglected. An optimization algorithm is used to minimize an objective function. The best configuration is selected as the treatment plan.

1 . (canceled) 
     
     
         2 . A computer-implemented method of determining a treatment for treating at least one target by emitting irradiation by a beam source through a beam shaping device in an irradiation direction movable around a movable patient support device, comprising:
 acquiring patient image data describing one or more anatomical body parts of a patient;   acquiring target data specifying at least one of the one or more anatomical body parts as at least one target for irradiation;   acquiring position data describing at least one position of the patient support device in relation to the irradiation direction;   determining target projection data based on the target data and the position data,
 wherein the target projection data is determined for the at least one target and for the at least one position of the patient support device in relation to the irradiation direction, and 
 wherein the target projection data describes outlines of the at least one target each projected into a plane perpendicular to a corresponding simulated beam direction specified by a corresponding position of the patient support device, 
   acquiring margin data describing one or more margins for the at least one target,
 wherein each of the one or more margins is a distance of a corresponding outline of the at least one projected target to a corresponding auxiliary outline correlated with the at least one target; 
   determining auxiliary outline data based on the target projection data and the margin data,
 wherein the auxiliary outline data is determined for the at least one target, for the at least one position of the patient support device in relation to the irradiation direction and for the one or more margins, and 
 wherein the auxiliary outline data describes one or more auxiliary outlines correlated with the at least one target, for the one or more margins; 
   determining beam shaping device data based on the auxiliary outline data,
 wherein the beam shaping device data describes one or more configurations of the beam shaping device; 
   determining irradiation data based on the patient image data and the beam shaping device data,
 wherein the irradiation data is determined for at least one voxel of the patient image data and for the one or more configurations of the beam shaping device, and 
 wherein the irradiation data describes a simulated irradiation dose received by the at least one voxel, for each of the one or more configurations of the beam shaping device described by the beam shaping device data; 
   acquiring constraint data describing criteria to be fulfilled by the treatment;   determining the treatment based on the irradiation data and the constraint data,
 wherein an arc weight is defined as a sum of monitor units to be emitted by the beam source during the treatment, and 
 wherein the treatment is determined based on different combinations of: the one or more margins, one or more arc weights, and one or more blockings for the one or more configurations of the beam shaping device; and 
   generating a control signal for emitting the irradiation to be emitted by the beam source according to the treatment.   
     
     
         3 . The method of  claim 2 , wherein the one or more auxiliary outlines specify one or more irradiation areas to receive irradiation emitted by the beam source. 
     
     
         4 . The method of  claim 2 , wherein the corresponding simulated beam direction is specified in relation to the irradiation direction. 
     
     
         5 . The method of  claim 2 , further comprising:
 acquiring path data describing one or more paths for the irradiation direction and/or the patient support device to move along during treatment, wherein the one or more paths are defined by one or more control points.   
     
     
         6 . The method of  claim 5 , wherein the one or more control points define one or more relative positions between the patient support device and the irradiation direction. 
     
     
         7 . The method of  claim 5 , wherein the one or more control points define a direction of movement for the irradiation direction relative to the patient support device. 
     
     
         8 . The method of  claim 5 , wherein for each of the one or more paths, monitor units to be emitted by the beam source during movement along a respective path is determined. 
     
     
         9 . The method of  claim 5 , wherein for each of the one or more paths, a corresponding configuration of the beam shaping device is determined. 
     
     
         10 . The method of  claim 5 , wherein:
 each of the one or more arc weights is associated with a respective path of the one or more paths, and   each of the one or more arc weights is determined based on a sum of monitor units to be emitted by the beam source during the treatment along the respective path.   
     
     
         11 . The method of  claim 2 , wherein each blocking, of the one or more blockings, corresponds to a configuration of the beam shaping device that prevents irradiation to an irradiation area at a corresponding control point. 
     
     
         12 . The method of  claim 2 , wherein the constraint data describes at least one of:
 a lower dose prescription limit specifying a minimum value of a sum of all simulated irradiation doses received by a first predetermined volumetric percentage of a target, of the at least one target, when following the treatment; and   an upper dose prescription limit specifying a minimum value of the sum of all simulated irradiation doses received by a second predetermined volumetric percentage of the target when following the treatment.   
     
     
         13 . The method of  claim 2 , wherein determining the treatment comprises:
 generating a plurality of auxiliary treatment steps, based on the different combinations of the one or more margins, the one or more arc weights and the one or more blockings; and   for each of the plurality of auxiliary treatment steps,
 determining target dose data based on the irradiation data, 
 wherein the target dose data is determined for the at least one target, and 
 wherein the target dose data describes the sum of all simulated irradiation doses received by the at least one target when following the plurality of auxiliary treatment steps, and 
   determining rating data at least based on the target dose data and the constraint data,
 wherein the rating data describes a degree to which the plurality of auxiliary treatment steps match the criteria to be fulfilled by the treatment; and 
   selecting one of the plurality of auxiliary treatment steps as the treatment based on the rating data.   
     
     
         14 . A medical system, comprising at least one computer having at least one processor operable to execute instructions of a computer program, to perform operations that comprises:
 acquiring patient image data describing one or more anatomical body parts of a patient;   acquiring target data specifying at least one of the one or more anatomical body parts as at least one target for irradiation;   acquiring position data describing at least one position of the patient support device in relation to the irradiation direction;   determining target projection data based on the target data and the position data,
 wherein the target projection data is determined for the at least one target and for the at least one position of the patient support device in relation to the irradiation direction, and 
 wherein the target projection data describes outlines of the at least one target each projected into a plane perpendicular to a corresponding simulated beam direction specified by a corresponding position of the patient support device, 
   acquiring margin data describing one or more margins for the at least one target,
 wherein each of the one or more margins is a distance of a corresponding outline of the at least one projected target to a corresponding auxiliary outline correlated with the at least one target; 
   determining auxiliary outline data based on the target projection data and the margin data,
 wherein the auxiliary outline data is determined for the at least one target, for the at least one position of the patient support device in relation to the irradiation direction and for the one or more margins, and 
 wherein the auxiliary outline data describes one or more auxiliary outlines correlated with the at least one target, for the one or more margins; 
   determining beam shaping device data based on the auxiliary outline data,
 wherein the beam shaping device data describes one or more configurations of the beam shaping device; 
   determining irradiation data based on the patient image data and the beam shaping device data,
 wherein the irradiation data is determined for at least one voxel of the patient image data and for the one or more configurations of the beam shaping device, and 
 wherein the irradiation data describes a simulated irradiation dose received by the at least one voxel, for each of the one or more configurations of the beam shaping device described by the beam shaping device data; 
   acquiring constraint data describing criteria to be fulfilled by the treatment;   determining the treatment based on the irradiation data and the constraint data,
 wherein an arc weight is defined as a sum of monitor units to be emitted by the beam source during the treatment, and 
 wherein the treatment is determined based on different combinations of: the one or more margins, one or more arc weights, and one or more blockings for the one or more configurations of the beam shaping device; and 
   generating a control signal for emitting the irradiation to be emitted by the beam source according to the treatment.   
     
     
         15 . The system of  claim 14 , wherein the one or more auxiliary outlines specify one or more irradiation areas to be irradiated via the beam source. 
     
     
         16 . The system of  claim 14 , wherein the corresponding simulated beam direction is specified in relation to the irradiation direction. 
     
     
         17 . The system of  claim 14 , wherein the at least one processor is operable to perform operations that further comprise:
 acquiring path data describing one or more paths for the irradiation direction and/or the patient support device to move along during treatment, wherein the one or more paths are defined by one or more control points.   
     
     
         18 . The system of  claim 17 , wherein the one or more control points define one or more relative positions between the patient support device and the irradiation direction. 
     
     
         19 . The system of  claim 17 , wherein the one or more control points define a direction of movement for the irradiation direction relative to the patient support device. 
     
     
         20 . The method of  claim 17 , wherein for each of the one or more paths, monitor units to be emitted by the beam source during movement along a respective path is determined. 
     
     
         21 . A non-transistory storage medium having instructions that, when executed by a processing device, cause the processing device to perform operations comprising:
 acquiring patient image data describing one or more anatomical body parts of a patient;   acquiring target data specifying at least one of the one or more anatomical body parts as at least one target for irradiation;   acquiring position data describing at least one position of the patient support device in relation to the irradiation direction;   determining target projection data based on the target data and the position data,
 wherein the target projection data is determined for the at least one target and for the at least one position of the patient support device in relation to the irradiation direction, and 
 wherein the target projection data describes outlines of the at least one target each projected into a plane perpendicular to a corresponding simulated beam direction specified by a corresponding position of the patient support device, 
 acquiring margin data describing one or more margins for the at least one target, 
 wherein each of the one or more margins is a distance of a corresponding outline of the at least one projected target to a corresponding auxiliary outline correlated with the at least one target; 
   determining auxiliary outline data based on the target projection data and the margin data,
 wherein the auxiliary outline data is determined for the at least one target, for the at least one position of the patient support device in relation to the irradiation direction and for the one or more margins, and 
 wherein the auxiliary outline data describes one or more auxiliary outlines correlated with the at least one target, for the one or more margins; 
   determining beam shaping device data based on the auxiliary outline data,
 wherein the beam shaping device data describes one or more configurations of the beam shaping device; 
   determining irradiation data based on the patient image data and the beam shaping device data,
 wherein the irradiation data is determined for at least one voxel of the patient image data and for the one or more configurations of the beam shaping device, and 
 wherein the irradiation data describes a simulated irradiation dose received by the at least one voxel, for each of the one or more configurations of the beam shaping device described by the beam shaping device data; 
   acquiring constraint data describing criteria to be fulfilled by the treatment;   determining the treatment based on the irradiation data and the constraint data,
 wherein an arc weight is defined as a sum of monitor units to be emitted by the beam source during the treatment, and 
 wherein the treatment is determined based on different combinations of: the one or more margins, one or more arc weights, and one or more blockings for the one or more configurations of the beam shaping device; and 
   generating a control signal for emitting the irradiation to be emitted by the beam source according to the treatment.   
     
     
         22 . A computer-implemented method for emitting irradiation by a beam source through a beam shaping device in an irradiation direction movable around a movable patient support device, comprising:
 acquiring patient image data describing one or more anatomical body parts of a patient;   acquiring target data specifying at least one of the one or more anatomical body parts as at least one target for irradiation;   acquiring position data describing at least one position of the patient support device in relation to the irradiation direction;   determining target projection data based on the target data and the position data,
 wherein the target projection data is determined for the at least one target and for the at least one position of the patient support device in relation to the irradiation direction, and 
 wherein the target projection data describes outlines of the at least one target each projected into a plane perpendicular to a corresponding simulated beam direction specified by a corresponding position of the patient support device, 
   acquiring margin data describing one or more margins for the at least one target,
 wherein each of the one or more margins is a distance of a corresponding outline of the at least one projected target to a corresponding auxiliary outline correlated with the at least one target; 
   determining auxiliary outline data based on the target projection data and the margin data,
 wherein the auxiliary outline data is determined for the at least one target, for the at least one position of the patient support device in relation to the irradiation direction and for the one or more margins, and 
   wherein the auxiliary outline data describes one or more auxiliary outlines correlated with the at least one target, for the one or more margins;   determining beam shaping device data based on the auxiliary outline data,   determining irradiation data based on the patient image data and the beam shaping device data,
 wherein the irradiation data is determined at least for at least one voxel of the patient image data, and 
 wherein the irradiation data describes a simulated irradiation dose received by the at least one voxel, for each of a plurality of configurations of the beam shaping device described by the beam shaping device data; 
   determining treatment data based on the irradiation data and the constraint data, and   generating a control signal for causing emission of the irradiation by the beam source according to the treatment data.