Variance reduction simulation system, program product, and related methods
First Claim
1. A system for increasing efficiency in a simulation of particle transport through a medium, comprising:
- a communication network;
an image gathering device accessible to the communication network to provide an at least two-dimensional image slice of a target volume and an adjacent structure volume in a patient;
a radiation treatment planning computer in communication with the image gathering device and having memory, a processor coupled to the memory, and radiation treatment planning program product stored in the memory adapted to produce an optimized radiation treatment plan for delivering radiation to the target volume;
a radiation beam source to deliver radiation to the target according to the radiation treatment plan;
a simulation data administrator server in communication with the communication network and having access to an interaction database including records related to parameters describing interactions of particles in an absorbing medium to provide particle interaction parameters;
a simulated dose calculation computer in communication with the radiation treatment planning computer and the simulation data administrator server through the communications network and including memory and a plurality of processors coupled to the memory to calculate a simulated absorbed dose in the absorbing medium deliverable according to the radiation treatment plan; and
simulated dose calculation program product stored in the memory of the simulated dose calculation computer and including instructions that when executed by at least one of the plurality of processors causes the at least one of the plurality of processors to perform the operation of modeling the target volume and adjacent structure volume to define the absorbing medium and to perform for each of a plurality of particles deliverable from the beam source the following simulation operations;
labeling the particle as a primary particle responsive to initiating a radiation delivery simulation through the absorbing medium according to the radiation treatment plan, transporting the primary particle through the absorbing medium, tracking the primary particle through the absorbing medium until undergoing a scattering event, determining the scattering event to have occurred, the scattering event resulting in a change in incident particle fluence with depth of propagation in the absorbing medium, consulting the interaction database responsive to the scattering event and retrieving data on the primary particle and any secondary particles resulting from the scattering event when so existing, recording energy deposited from the scattering event to thereby build a map of simulated absorbed dose, creating a new virtual particle defining a restored virtual particle responsive to the scattering event to thereby artificially restore incident particle fluence with depth of propagation in the absorbing medium changed in response to the scattering event, inheriting by the restored virtual particle properties from the primary particle, labeling the restored virtual particle as a primary particle and the original primary particle determined to have scattered as a scattered particle responsive to the scattering event, assigning a weight factor to each scattered virtual particle to compensate for artificial constancy of the particle fluence to thereby yield unbiased results for the simulated absorbed dose, and producing a three-dimensional map of simulated absorbed dose delivered to the absorbing medium.
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Accused Products
Abstract
A system to provide enhanced computational efficiency in a simulation of particle transport through a medium, program product, and related methods are provided. The system can include a simulation data administrator server having access to an interaction database including records related to parameters describing interactions of particles in an absorbing medium to provide particle interaction parameters, and a simulated dose calculation computer in communication with the simulation data administrator server through a communications network. The system can also included simulated dose calculation program product stored in memory of the simulated dose calculation computer and including instructions that when executed by a processor causes the processor to perform for each of a plurality of particles deliverable from a particle source the operations of providing parameters for a medium to perform a Monte Carlo simulation to develop a map of simulated absorbed dose in the medium, and artificially adjusting simulation particle fluxes to achieve a substantially constant variance throughout a depth of the medium.
48 Citations
56 Claims
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1. A system for increasing efficiency in a simulation of particle transport through a medium, comprising:
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a communication network;
an image gathering device accessible to the communication network to provide an at least two-dimensional image slice of a target volume and an adjacent structure volume in a patient;
a radiation treatment planning computer in communication with the image gathering device and having memory, a processor coupled to the memory, and radiation treatment planning program product stored in the memory adapted to produce an optimized radiation treatment plan for delivering radiation to the target volume;
a radiation beam source to deliver radiation to the target according to the radiation treatment plan;
a simulation data administrator server in communication with the communication network and having access to an interaction database including records related to parameters describing interactions of particles in an absorbing medium to provide particle interaction parameters;
a simulated dose calculation computer in communication with the radiation treatment planning computer and the simulation data administrator server through the communications network and including memory and a plurality of processors coupled to the memory to calculate a simulated absorbed dose in the absorbing medium deliverable according to the radiation treatment plan; and
simulated dose calculation program product stored in the memory of the simulated dose calculation computer and including instructions that when executed by at least one of the plurality of processors causes the at least one of the plurality of processors to perform the operation of modeling the target volume and adjacent structure volume to define the absorbing medium and to perform for each of a plurality of particles deliverable from the beam source the following simulation operations;
labeling the particle as a primary particle responsive to initiating a radiation delivery simulation through the absorbing medium according to the radiation treatment plan, transporting the primary particle through the absorbing medium, tracking the primary particle through the absorbing medium until undergoing a scattering event, determining the scattering event to have occurred, the scattering event resulting in a change in incident particle fluence with depth of propagation in the absorbing medium, consulting the interaction database responsive to the scattering event and retrieving data on the primary particle and any secondary particles resulting from the scattering event when so existing, recording energy deposited from the scattering event to thereby build a map of simulated absorbed dose, creating a new virtual particle defining a restored virtual particle responsive to the scattering event to thereby artificially restore incident particle fluence with depth of propagation in the absorbing medium changed in response to the scattering event, inheriting by the restored virtual particle properties from the primary particle, labeling the restored virtual particle as a primary particle and the original primary particle determined to have scattered as a scattered particle responsive to the scattering event, assigning a weight factor to each scattered virtual particle to compensate for artificial constancy of the particle fluence to thereby yield unbiased results for the simulated absorbed dose, and producing a three-dimensional map of simulated absorbed dose delivered to the absorbing medium. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A system for increasing efficiency in a simulation of particle transport through a medium, comprising:
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a simulated dose calculation computer including memory and at least one processor coupled to the memory to calculate a simulated absorbed dose in an absorbing medium; and
simulated dose calculation program product stored in the memory of the simulated dose calculation computer and including instructions that when executed by the at least one processor causes the at least one processor to perform the following simulation operations;
labeling a particle as a primary particle responsive to initiating a radiation delivery simulation, creating a new virtual particle defining a restored virtual particle responsive to a collision event involving the primary particle, labeling the restored virtual particle as a primary particle and the original primary particle as a scattered particle responsive to the collision event; and
restoring incident particle fluence with depth of propagation in the absorbing medium changed in response to the collision event. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A method of increasing efficiency in a simulation of particle transport through a medium, comprising the steps of:
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selecting an original particle from a radiation source;
tracking the selected original particle through a medium until undergoing a collision event, the collision event resulting in a change in incident particle fluence with depth of propagation in the medium;
consulting an interaction database responsive to the collision event;
retrieving data on the original particle and each secondary particle resulting from the collision event;
recording energy deposited from the collision event; and
creating a new virtual particle defining a restored virtual particle responsive to the collision event to thereby artificially restore incident particle fluence with depth of propagation in the medium changed in response to the collision event. - View Dependent Claims (26, 27, 28)
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29. A method of increasing efficiency in a simulation of particle transport through a medium by reducing a number of required particles to be tracked, the method comprising the steps of:
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labeling each of a plurality of original primary particles from a particle beam source separately as a primary particle;
transporting each of the plurality of original primary particles through an absorbing medium;
creating a new virtual particle defining a restored virtual particle responsive to a collision event of one of the plurality of original primary particles;
inheriting properties by the restored virtual particle from the collided original primary particle; and
labeling the restored virtual particle as a primary particle and the original primary particle as a scattered particle responsive to the collision event. - View Dependent Claims (30, 31, 32, 33, 34, 35)
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36. A method to increase efficiency of Monte Carlo simulations of particle transport or radiation fluxes, comprising the steps of:
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providing parameters for a medium to perform a Monte Carlo simulation thereon; and
artificially adjusting simulation particle fluxes to achieve a substantially constant accuracy throughout a depth of the medium. - View Dependent Claims (37, 38, 39)
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40. A computer readable medium that is readable by at least one computer processor, the computer readable medium comprising a set of instructions that, when executed by the at least one computer processor, cause the at least one computer processor to perform the following operations:
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selecting a particle from a radiation source;
tracking the selected particle through a medium until undergoing a collision event, the collision event resulting in a change in incident particle fluence with depth of propagation in the medium;
consulting an interaction database responsive to the collision event;
retrieving data on the particle and each secondary particle resulting from the collision event;
recording energy deposited from the collision event; and
creating a new virtual particle defining a restored virtual particle responsive to the collision event to thereby artificially restore incident particle fluence with depth of propagation in the medium changed in response to the collision event. - View Dependent Claims (41, 42, 43)
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44. A computer readable medium that is readable by at least one computer processor, the computer readable medium comprising a set of instructions that, when executed by the at least one computer processor, cause the at least one computer processor to perform the following operations:
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creating a new virtual particle defining a restored virtual particle responsive to a collision event, the collision event resulting in a change in incident particle fluence with depth of propagation in a medium;
labeling the restored virtual particle as a primary particle and an original primary particle determined to have collided as a scattered particle responsive to the collision event; and
restoring incident particle fluence with depth of propagation in the medium changed in response to the collision event. - View Dependent Claims (45, 46, 47, 48, 49, 50, 51, 52, 53)
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54. A computer readable medium that is readable by at least one computer processor, the computer readable medium comprising a set of instructions that, when executed by the at least one computer processor, cause the at least one computer processor to perform the following operations:
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providing parameters for a medium to perform a Monte Carlo simulation thereon; and
artificially adjusting simulation particle fluxes to achieve a substantially constant variance throughout a depth of the medium. - View Dependent Claims (55, 56)
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Specification