A computer-implemented medical method of determining position correction data for compensating for tracking inaccuracies, the method comprising the following steps: a) spatial image data is acquired which describes a three-dimensional representation of an anatomical body part; b) target position data is acquired which describes a desired spatial position of a trackable device with respect to the three-dimensional representation of the body part; c) spatial registration data is acquired which describes a spatial registration of the three-dimensional representation of the body part together with the desired spatial position of the trackable device, and the body part; d) tracking position data is acquired which describes a current spatial position of the trackable device; e) control data is determined based on the spatial registration data and the tracking position data, which describes instructions for positioning the trackable device at the desired spatial position with respect to the body part; f) imaging setup data is acquired which describes a positional setup of a projection imaging device for acquiring a two-dimensional projection image of the body part and of the trackable device positioned, based on the control data, at the desired spatial position; g) projection image data is acquired which describes the two-dimensional projection image; the method being characterized by the following steps: h) position verification data is determined based on the imaging setup data, the projection image data and the spatial registration data, which describes a deviation of the current spatial position of the trackable device as shown in the two-dimensional projection image, and the desired spatial position of the trackable device; i) position correction data is determined based on the position verification data, describing a positional compensation of the deviation of the spatial position of the trackable device. a) spatial image data is acquired which describes a three-dimensional representation of an anatomical body part; b) target position data is acquired which describes a desired spatial position of a trackable device with respect to the three-dimensional representation of the body part; c) spatial registration data is acquired which describes a spatial registration of the three-dimensional representation of the body part together with the desired spatial position of the trackable device, and the body part; d) tracking position data is acquired which describes a current spatial position of the trackable device; e) control data is determined based on the spatial registration data and the tracking position data, which describes instructions for positioning the trackable device at the desired spatial position with respect to the body part; f) imaging setup data is acquired which describes a positional setup of a projection imaging device for acquiring a two-dimensional projection image of the body part and of the trackable device positioned, based on the control data, at the desired spatial position; g) projection image data is acquired which describes the two-dimensional projection image; the method being characterized by the following steps: h) position verification data is determined based on the imaging setup data, the projection image data and the spatial registration data, which describes a deviation of the current spatial position of the trackable device as shown in the two-dimensional projection image, and the desired spatial position of the trackable device; i) position correction data is determined based on the position verification data, describing a positional compensation of the deviation of the spatial position of the trackable device. h) position verification data is determined based on the imaging setup data, the projection image data and the spatial registration data, which describes a deviation of the current spatial position of the trackable device as shown in the two-dimensional projection image, and the desired spatial position of the trackable device; i) position correction data is determined based on the position verification data, describing a positional compensation of the deviation of the spatial position of the trackable device.