Methods to optimize coverage for multiple targets simultaneously for radiation treatments

A method of determining a radiation treatment plan for concurrent treatment of multiple target volumes within a patient using a radiation treatment system, the method comprising:

• receiving, at a computer system, a first desired value for a relative volumetric coverage at a first lower dose objective for a first target volume within the patient, and a second desired value for a relative volumetric coverage at a second lower dose objective for a second target volume within the patient;
• obtaining, by the computer system, a cost function including a first term with a first weight and a second term with a second weight, the first term relating to a first difference between an average relative volumetric coverage and the relative volumetric coverage for the first target volume, the second term relating to a second difference between the average relative volumetric coverage and the relative volumetric coverage for the second target volume, the average relative volumetric coverage being an average of the relative volumetric coverage for the first target volume and the relative volumetric coverage for the second target volume;
• for each of a plurality of iterations:
• determining, by the computer system, a set of control point sequence for the radiation treatment system;
• evaluating, by the computer system, the relative volumetric coverage for the first target volume and the relative volumetric coverage for the second target volume based on the set of control point sequence;
• evaluating, by the computer system, a current value of the cost function based on the evaluated relative volumetric coverage for the first target volume and the evaluated relative volumetric coverage for the second target volume;
• and
• updating, by the computer system, the set of control point sequence based on the current value of the cost function;
• and
• determining, by the computer system, an optimal radiation treatment plan by performing the plurality of iterations, wherein the optimal radiation treatment plan includes an optimal set of control point sequence corresponding to an optimal value for the cost function that meets a pre-determined convergence criterion.

A method of determining a radiation treatment plan for concurrent treatment of multiple target volumes within a patient using a radiation treatment system, the method comprising:

• receiving, at a computer system, a first desired value for a relative volumetric coverage at a first lower dose objective for the first target volume within the patient, and a second desired value for a relative volumetric coverage at a second lower dose objective for the second target volume within the patient;
• obtaining, by the computer system, a cost function including a first term with a first weight and a second term with a second weight, the first term relating to a deficiency of the relative volumetric coverage for the first target volume with respect to the first desired value, and the second term relating to a deficiency of the relative volumetric coverage for the second target volume with respect to the second desired value;
• performing, by the computer system, a first iteration of an optimization using the cost function to obtain a first intermediate radiation treatment plan, the first intermediate radiation treatment plan including a first set of control point sequence for the radiation treatment system for producing a first dose distribution corresponding to a first cost value of the cost function;
• calculating, by the computer system, a first value for the relative volumetric coverage for the first target volume and a second value for the relative volumetric coverage for the second target volume based on the first dose distribution;
• adjusting, by the computer system, the first weight based on a first difference between the first desired value and the first value;
• adjusting, by the computer system, the second weight based on a second difference between the second desired value and the second value;
• and
• performing, by the computer system, a second iteration of the optimization using the cost function with the adjusted first weight and the adjusted second weight to obtain a second intermediate radiation treatment plan, the second intermediate radiation treatment plan including a second set of control point sequence for the radiation treatment system for producing a second dose distribution corresponding to a second cost value of the cost function that is lower than the first cost value.