The invention is directed to a data processing method of displaying a radiation dose distribution in tissue of a patient and a corresponding program and computer running the program, the steps of the method being executed by a computer and comprising: a) acquiring medical image data comprising medical image information describing an anatomical body part b) acquiring, based on the medical image data, irradiation eligibility data comprising irradiation eligibility information describing an eligibility class to which the anatomical body part belongs, the eligibility class describing the eligibility of the anatomical body part for irradiation with treatment radiation c) acquiring dose distribution data comprising dose distribution information describing a radiation dose distribution in the anatomical body part d) displaying, on a display device, the dose distribution information in the medical image information based on the irradiation eligibility data and based on using a colour range which represents the dose distribution information.
