In a device, method and computer program product for generation of an exposure plan for irradiating a patient, at least one reference data set independent of the patient is provided, from which an attenuation of high-energy radiation upon passage through a reference body can be determined. A patient magnetic resonance image of the patient is adapted using the reference data set and an exposure plan is generated based on the patient magnetic resonance image and the patient-specific attenuation of high-energy radiation upon passage through the patient. The patient-specific attenuation of high-energy radiation upon passage through the patient is determined using the adaptation of the patient magnetic resonance image with the reference data set.