A method for determining an irradiation plan includes specifying a target volume to be irradiated and a condition to be fulfilled, and implementing a first optimization. Implementing the first optimization includes providing a first data record, in which the target volume is mapped, and determining a first parameter set for the irradiation planning by implementing a first optimization algorithm. The first parameter set is optimized with respect to the condition to be fulfilled by using the first data record. The method also includes implementing a second optimization that includes providing a second data record that has a higher resolution than the first data record, determining a second parameter set by implementing a second optimization algorithm. The second parameter set is optimized with respect to the condition to be fulfilled by using the second data record and using the first parameter set. The method also includes generating an irradiation planning data record from the second parameter set.
