Intensity-modulated proton therapy

A method for performing intensity-modulated ion therapy, the method comprising:

• generating a representation of a patient by:
• for a plurality of ions, estimating a path taken by each ion within the patient based at least in part on trajectories determined from measured data;
• determining a system of equations of the form Ax=b where x represents a distribution parameter associated with the patient, b represents interaction quantities of the plurality of ions resulting from interactions within the patient, and A represents an operator that operates on x to yield b, the operating having information about the estimated paths of the plurality of ions in the patient;
• determining one or more feasible solutions to the system of equations by perturbing an estimated initial solution to determine whether the perturbation yields a superior reconstruction than a non-perturbed solution;
• and
• calculating the distribution parameter associated with the patient;
• identifying a volume of interest from the representation of the patient, the volume of interest divided into a total number of voxels ordered according to distance to a feature of interest;
• defining a plurality of sub-volumes wherein a sub-volume comprises a number of consecutive ordered voxels, wherein a ratio of the number consecutive ordered voxels comprising the sub-volume to the total number of voxels is approximately equal to a target fractional value for the sub-volume;
• and
• generating an ion treatment plan that satisfies dose constraints for each of the plurality of sub-volumes.

An intensity-modulated ion therapy system comprising:

• an ion delivery system configured to deliver a plurality of ions according to an ion treatment plan;
• a computed tomography system configured to generate a representation of a patient, the computed tomography system comprising a hardware processor configured to:
• for a plurality of ions, estimate a path taken by each ion within the patient based at least in part on trajectories determined from measured data;
• determine a system of equations of the form Ax=b where x represents a distribution parameter associated with the patient, b represents interaction quantities of the plurality of ions resulting from interactions within the patient, and A represents an operator that operates on x to yield b, the operating having information about the estimated paths of the plurality of ions in the patient;
• determine one or more feasible solutions to the system of equations by perturbing an estimated initial solution to determine whether the perturbation yields a superior reconstruction than a non-perturbed solution;
• and
• calculate the distribution parameter associated with the patient;
• and
• a treatment plan system configured to generate the ion treatment plan, the treatment plan system comprising a hardware processor configured to:
• identify a volume of interest from the representation of the patient, the volume of interest divided into a total number of voxels ordered according to distance to a feature of interest;
• define a plurality of sub-volumes wherein a sub-volume comprises a number of consecutive ordered voxels, wherein a ratio of the number consecutive ordered voxels comprising the sub-volume to the total number of voxels is approximately equal to a target fractional value for the sub-volume;
• and
• generate the ion treatment plan that satisfies dose constraints for each of the plurality of sub-volumes.