Methods of use of ultra-high dose rate radiation and therapeutic agent

A non-transitory computer-readable storage medium having computer-executable instructions for causing a computing system to perform a method of ultra-high-dose-rate (FLASH) radiation treatment planning for treating a tumor in combination with a therapeutic agent, the method comprising:

• accessing values of parameters from memory of the computing system, wherein the parameters comprise directions of beams to be directed into sub-volumes in a target and beam energies for the beams;
• accessing information that specifies limits for the radiation treatment plan, wherein the limits are based on a dose threshold and comprise a limit on irradiation time for each sub-volume outside the target;
• wherein the information that specifies limits comprises information about treatment of the tumor with a therapeutic agent;
• and
• adjusting the values of the parameters that affect a calculated amount of dose to be delivered by the beams until differences between respective total values for the sub-volumes satisfy a threshold value.

A computer-implemented method of radiation treatment planning for a treating a tumor in combination with an immune modulator, the method comprising:

• determining a prescribed dose of ultra-high-dose-rate (FLASH) radiation to be delivered into and across a tumor target, wherein the prescribed dose is determined based on a response of the tumor to a therapeutic agent;
• accessing values of parameters comprising a number of beams in a plurality of beams to be directed into sub-volumes in the target, directions of the plurality of beams, and beam energies for the plurality of beams, wherein each of the beams comprises a plurality of beam segments;
• identifying any overlapping beams in the plurality of beams that have respective beam paths that overlap outside the target;
• for each beam in the plurality of beams, determining a maximum beam energy for the beam and determining beam energies for the beam segments of the beam as a percentage of the maximum beam energy for the beam;
• and
• for each overlapping beam of the overlapping beams that overlap outside the target, reducing the beam intensities for the beam segments of the overlapping beam by a dose calculation factor, wherein the beam intensities for the beam segments for the plurality of beams are determined such that a cumulative dose delivered to the target satisfies the prescribed dose.