Method and apparatus for performing irradiation time optimization for intensity modulated proton therapy

A computer-implemented method of determining a resultant treatment plan for a proton radiation therapy system based on a given dose volume constraint, wherein the resultant treatment plan is optimized for treatment time. The method includes accessing a dose volume constraint and range information, wherein the range information indicates an acceptable deviation from the dose volume constraint; accessing machine configuration information including a plurality of machine parameters based on the proton radiation therapy system, the plurality of machine parameters defining a maximum resolution that the proton radiation therapy system can reach when irradiating the patient; iteratively adjusting the plurality of machine parameters to a value that reduces the maximum resolution, and simulating the plurality of candidate treatment plans to generate a plurality of treatment planning results, where each treatment planning result includes a respective treatment time and a respective planning quality; and selecting a res