1. A system for determining a transformation between different coordinate systems associated with different medical data, comprising: a landmark input for obtaining first coordinates representing a first set of anatomical landmarks in a first coordinate system and second coordinates representing a second set of anatomical landmarks in a second coordinate system; a matching subsystem configured for: providing reference coordinates representing a third set of anatomical landmarks in a reference coordinate system, the third set of anatomical landmarks comprising the first set of anatomical landmarks and the second set of anatomical landmarks; and determining a transformation between the first coordinate system and the second coordinate system by: i) determining a first intermediate transformation between the first coordinate system and the reference coordinate system by matching the first set of anatomical landmarks to the third set of anatomical landmarks; ii) determining a second intermediate transformation between the second coordinate system and the reference coordinate system by matching the second set of anatomical landmarks to the third set of anatomical landmarks; and iii) combining the first intermediate transformation and the second intermediate transformation to obtain the transformation.