A data processing method for determining an infusion location in an anatomical region of interest of a patient's body for infusing a medical substance, the method being executed by a computer and comprising steps of: a) acquiring (S3.1) region of interest data comprising information about the position of the region of interest, the region of interest comprising a target region which is to be treated by infusing the medical substance; b) acquiring (S2.2) permeability data comprising information about the permeability of anatomical vessels in the body; c) acquiring (S2.1) body vessel set data comprising information about a body vessel set, wherein the body vessel set represents a set of anatomical body vessels in the patient's body and wherein the body vessel set data comprises information about the spatial structure of the body vessels; d) acquiring (S3.10) coverage condition data comprising information about a predetermined coverage of the target region with the medical substance; and e) determining (S3.4), for a plurality of candidate infusion locations, candidate coverage data comprising information about a candidate coverage of the target region with the medical substance based on the permeability data, the body vessel set data and the coverage condition data; f) determining (S3.3) relevant vessel set data based on the body vessel set data, the relevant vessel set data comprising information about a relevant vessel set of relevant vessels, wherein the relevant vessel set is determined based on the position of the body vessels relative to the target region; g) determining (S3.12) infusion location data comprising information about the infusion location based on the permeability data and the body vessel set data and the candidate coverage data wherein the infusion location is located in an infusion segment of a relevant vessel; characterized by h) determining a body fluid volume in the infusion segment and determining a concentration of the medical substance in the infusion segment, wherein a concentration of the medical substance in the tissue surrounding the infusion segment is determined based on the permeability data. a) acquiring (S3.1) region of interest data comprising information about the position of the region of interest, the region of interest comprising a target region which is to be treated by infusing the medical substance; b) acquiring (S2.2) permeability data comprising information about the permeability of anatomical vessels in the body; c) acquiring (S2.1) body vessel set data comprising information about a body vessel set, wherein the body vessel set represents a set of anatomical body vessels in the patient's body and wherein the body vessel set data comprises information about the spatial structure of the body vessels; d) acquiring (S3.10) coverage condition data comprising information about a predetermined coverage of the target region with the medical substance; and e) determining (S3.4), for a plurality of candidate infusion locations, candidate coverage data comprising information about a candidate coverage of the target region with the medical substance based on the permeability data, the body vessel set data and the coverage condition data; f) determining (S3.3) relevant vessel set data based on the body vessel set data, the relevant vessel set data comprising information about a relevant vessel set of relevant vessels, wherein the relevant vessel set is determined based on the position of the body vessels relative to the target region; g) determining (S3.12) infusion location data comprising information about the infusion location based on the permeability data and the body vessel set data and the candidate coverage data wherein the infusion location is located in an infusion segment of a relevant vessel; characterized by h) determining a body fluid volume in the infusion segment and determining a concentration of the medical substance in the infusion segment, wherein a concentration of the medical substance in the tissue surrounding the infusion segment is determined based on the permeability data.