The idea concerns irradiation of a target volume (53), wherein intensities for target points (70) are determined which are sequentially approached by a beam, comprising the following steps: detecting a volume (63) to be protected, wherein a dose generated by irradiating a target volume (53) does not exceed a predetermined maximum value； determining intensities for target points (70) in such a way that within the volume (63) to be protected the generated dose does not exceed the predetermined maximum value, wherein a dose contribution data record is used for determining the intensities, which dose contribution data record comprises the dose generated at other spots (73) by directing the beam (10) on one of the target points (70) with a predetermined intensity.
