A radiotherapy treatment plan for irradiation of an object to be irradiated is determined. The object to be irradiated includes a number of irradiation areas and the object to be irradiated is irradiated with a number of beams from different directions. The method includes determining a number of total dose conditions. One of the number of total dose conditions is assigned to a respective one of the number of irradiation areas. The method further includes determining a number of single beam dose conditions. One of the single dose conditions is assigned to a respective one of the number of beams and a respective one of the number of irradiation areas. The method also includes determining irradiation parameters for the number of beams as a function of the number of total dose conditions and the number of single beam dose conditions.
