Apparatus for radiotherapy and method of operating an apparatus for radiotherapy

A machine-readable storage medium having computer-executable instructions stored, that, when executed, cause one or more processors to perform:

• control of at least one first radiation source to irradiate a target region with one or more ultra-high dose rate charged particle beams;
• and
• control of at least one second radiation source to irradiate the target region with one or more intensity-modulated beams,
• wherein control of the at least one first radiation source and the at least one second radiation source is performed such that the one or more ultra-high dose rate charged particle beams and the one or more intensity-modulated beams provide a substantially uniform total dose distribution across the target region, and
• a controller is further configured to control the at least one first radiation source to generate the one or more ultra-high dose rate charged particle beams and control the at least one second radiation source to generate the one or more intensity-modulated beams such that a first dose distribution of the one or more ultra-high dose rate charged particle beams and a second dose distribution of the one or more intensity-modulated beams combine in the target region to provide the substantially uniform total dose distribution across the target region, in particular across substantially the entire target region.