1. A data processing method for planning an infusion of a medical substance into a target region in an anatomical body part, wherein the medical substance is to be infused by means of an infusion setup which comprises an infusion device for performing the infusion as well as the medical substance, the method comprising: a) acquiring target region geometry data comprising target region geometry information describing the geometry of the target region; b) acquiring target coverage data comprising target coverage information describing a planned coverage of the target region by the medical substance, wherein the target coverage data is acquired based on the target region geometry data; c) acquiring, based on selecting a predetermined spatial distribution of the medical substance in the target region based on the target coverage data, relationship data comprising relationship information which describes a relationship between at least one physical parameter of the infusion setup and a predetermined spatial distribution of the medical substance, wherein the physical parameter describes at least one of a geometric or surface property of the infusion device, a fluid dynamic property of the medical substance and time; d) determining infusion setup data comprising infusion setup information which describes a planned infusion setup, based on the relationship data and the target coverage data.