System and method for novel chance-constrained optimization in intensity-modulated proton therapy planning to account for range and patient setup uncertainties

A treatment planning system for use in intensity-modulated proton therapy, comprising:

• a memory for storing thereon a representation of a subject and a proton beam configuration, wherein the representation of the subject includes information related to target and non-target volumes of interest and the proton beam configuration describes a number of beamlets and their respective arrangement;
• a processor configured for receiving the representation of the subject and the proton beam configuration from the memory and for generating a treatment plan based on the representation of the subject and the proton beam configuration;
• a display for displaying the treatment plan;
• and
• wherein the processor is configured to generate the treatment plan by:
• obtaining a target dose distribution model in the target volumes, prescribed doses of the target volumes, and dose constraints in the non-target volumes;
• computing an objective function, using the treatment planning system, the objective function having a first part with dose deviations from the prescribed doses in the target volumes, a second part with dose deviations from the dose constraints in the non-target volumes, and computing dose volume constraints for targets using a probability controlling a dose distribution in the target volumes between a lower threshold and an upper threshold;
• and
• generating the treatment plan executable by a proton treatment system by optimizing the objective function to determine a set of intensity weights for each beamlet in the proton beam configuration.

A method for generating an intensity modulated proton therapy plan amenable to uncertainties, the method comprising:

• (a) obtaining, by a treatment planning system, a representation of a subject that includes information related to target and non-target volumes of interest (VOIs);
• (b) obtaining, by the treatment planning system, a proton beam configuration that describes a number of beamlets and their respective arrangement;
• (c) obtaining, by the treatment planning system, a target dose distribution model in the target VOIs, prescribed doses for the target VOIs, and dose constraints for the non-target VOIs;
• (d) computing dose volume constraints for the target VOIs using a selectable parameter controlling a probability for a dose distribution in the target VOIs to be between a lower threshold and an upper threshold;
• (e) optimizing an objective function with the treatment planning system to determine a set of intensity weights for each beamlet in the proton beam configuration, wherein the objective function is calculated using dose deviations from the prescribed doses in the target VOIs, dose deviations from the dose constraints in the non-target VOIs, and the dose volume constraints for the target VOIs;
• and
• (f) generating a treatment plan, executable by a proton treatment system, with the treatment planning system using the intensity weights determined by optimizing the objective function.