Disclosed is a computer-implemented medical method of determining the position of an anatomical region of interest of a patient's body, the method comprising the following steps: a) finger model data is acquired (S11) which describes at least one model of a pose of at least one finger of a user； b) finger position data is acquired (S12) based on the finger model data and based on imaging the at least one finger, wherein the finger position data describes a position of the at least one finger at which the at least one finger points at the anatomical region of interest and wherein the finger position data is acquired by extracting, from a camera image generated by the imaging and describing the at least one finger, the position of the image representation of at least part of the at least one finger by comparing the camera image to the model of the at least one finger； c) planning image data is acquired (S13) which describes a planning external surface of the anatomical region of interest； d) anatomical region position data is determined (S14) based on the finger position data and the planning image data, wherein the anatomical region position data describes the position of the anatomical region of interest, wherein the anatomical region position data is determined by determining, based on the finger position data, an actual surface of the anatomical region of interest and comparing the actual external surface to the planning external surface, wherein the actual surface is determined by generating or represented by a point cloud of positions of the at least one finger, wherein the actual external surface is determined to be the planning external surface if the comparison between the actual external surface and the planning external surface results in that the actual external surface is similar to the planning external surface at least to a predetermined degree of similarity, wherein the finger model data describes a user-specific model of the pose which is acquired by
