Systems and methods for intensity modulated radiation therapy
First Claim
1. A method for performing intensity-modulated radiation therapy on a subject using a plurality of pencil beams, the method comprising:
- identifying a volume of interest from a representation of the subject, the volume of interest divided into a total number of voxels;
defining a plurality of sub-volumes, wherein a sub-volume comprises a number of contiguous, ordered voxels; and
generating a treatment plan for intensity-modulated radiation therapy that satisfies dose constraints for each voxel within each of the plurality of sub-volumes;
wherein generating the treatment plan comprises;
determining a system of linear equations of the form Ax*=b or linear inequalities of the form bmin≦
Ax*≦
bmax where x* is a first vector comprising elements xi representing an ith component of a solution vector representing an actual intensity of an ith pencil beam, b is a second vector comprising elements bj representing a dose prescribed for a jth dose grid point, bmin is a third vector comprising elements bminj representing a minimum dose prescribed for a jth dose grid point, bmax is a fourth vector comprising elements bmaxj representing a maximum dose prescribed for a jth dose grid point, and A is a matrix comprising elements aij representing a dose delivered by the ith pencil beam of unit intensity to the jth dose grid point; and
determining one or more feasible solutions x* to the system of equations or inequalities using a feasibility-seeking algorithm.
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Accused Products
Abstract
Embodiments disclosed herein include methods for performing intensity-modulated radiation therapy on a subject using a plurality of pencil beams. The methods can include generating a treatment plan for intensity-modulated radiation therapy that satisfies dose constraints for each of a plurality of sub-volumes. The treatment plan can be generated using a superiorization technique that reduces total variation in dose space. Additional dose-volume constraints that permit a fraction of treatment doses to violate a prescription by up to a defined percentage of intensity can be used to assist in determining the treatment plan.
187 Citations
35 Claims
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1. A method for performing intensity-modulated radiation therapy on a subject using a plurality of pencil beams, the method comprising:
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identifying a volume of interest from a representation of the subject, the volume of interest divided into a total number of voxels; defining a plurality of sub-volumes, wherein a sub-volume comprises a number of contiguous, ordered voxels; and generating a treatment plan for intensity-modulated radiation therapy that satisfies dose constraints for each voxel within each of the plurality of sub-volumes; wherein generating the treatment plan comprises; determining a system of linear equations of the form Ax*=b or linear inequalities of the form bmin≦
Ax*≦
bmax where x* is a first vector comprising elements xi representing an ith component of a solution vector representing an actual intensity of an ith pencil beam, b is a second vector comprising elements bj representing a dose prescribed for a jth dose grid point, bmin is a third vector comprising elements bminj representing a minimum dose prescribed for a jth dose grid point, bmax is a fourth vector comprising elements bmaxj representing a maximum dose prescribed for a jth dose grid point, and A is a matrix comprising elements aij representing a dose delivered by the ith pencil beam of unit intensity to the jth dose grid point; anddetermining one or more feasible solutions x* to the system of equations or inequalities using a feasibility-seeking algorithm. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method for performing intensity-modulated radiation therapy, the method comprising:
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obtaining a representation of a patient, the representation comprising information about structures within or on the patient; identifying a target volume in the representation of the patient; identifying an organ at risk or other non-targeted tissue in the representation of the patient; dividing the target volume into a first plurality of sub-volumes, wherein dividing the target volume into a first plurality of sub-volumes comprises; dividing the target volume into a total number of voxels; selecting a first fractional value corresponding to a ratio of a size of a sub-volume of the target volume to a size of the target volume; and for each of the first plurality of sub-volumes, defining a sub-volume of the target volume as a group of a number of contiguous voxels, wherein a ratio of the number of contiguous voxels to the total number of voxels is approximately equal to the first fractional value for the sub-volume of the target volume for the target volume receiving a first violation constraint; for each voxel of the first plurality of sub-volumes, receiving a prescribed dose and a minimum dose constraint; selecting a radiation treatment plan that satisfies the first violation constraint, wherein the first violation constraint defines a fraction of the total number of voxels in the target volume that are permitted to receive a dose of radiation below the minimum dose constraint; and delivering radiation to the patient based on the selected radiation treatment plan. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 34, 35)
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24. An intensity-modulated radiation therapy system comprising:
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a radiation delivery system configured to deliver radiation to a patient; a physical processor configured to; analyze a representation of the patient to identify a target volume; divide the target volume into a total number of voxels such that the voxels can be arranged sequentially; define a first plurality of sub-volumes wherein a sub-volume comprises a set of a number of contiguous voxels, wherein a ratio of the number of contiguous voxels to the total number of voxels is approximately equal to a fractional value for the sub-volume; receive a minimum dose constraint for each voxel of the first plurality of sub-volumes; for the target volume, receive a first violation constraint; determine a radiation treatment plan that satisfies the first violation constraint; and select a radiation treatment plan that satisfies treatment criteria; and a control system configured to control the radiation delivery system to deliver the radiation according to the selected radiation treatment plan. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33)
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Specification