1. A system comprising: (a) a feature matching circuit configured to determine a substantial correspondence between (x) a present-location landmark subsurface feature of a cavity or lumen of an individual patient body part of an individual patient, the present-location landmark subsurface feature of the cavity or lumen including a subsurface vessel of the cavity or lumen, subsurface blood vessel of the cavity or lumen, subsurface vascular structure of the cavity or lumen, or a subsurface pattern presented by one or more blood vessel of the cavity or lumen of the individual patient body part, the cavity or lumen including an interior surface defining an interior thereof, and the present-location landmark subsurface feature is below the interior surface, the present-location landmark subsurface feature having a first spatial relationship to a distal end portion of a body-insertable device deployed in the individual patient, and (y) a candidate reference landmark subsurface feature of the cavity or lumen of the individual patient body part, the candidate reference landmark subsurface feature having a second spatial relationship to a particular selected target region of interest of the individual patient body part of at least two selected target regions of interest of the individual patient body part; (b) an event data circuit configured to generate data indicative of a proximity event, the proximity event including the distal end portion of the body-insertable device present at a location proximate to the particular selected target region of interest of the individual patient body part, the proximity event at least partially based on the determined substantial correspondence; (c) a list management circuit configured to add the proximity event to a proximity event list for the individual patient body part; (d) a non-transitory computer-readable media configured to maintain informational data corresponding to the proximity event list for the individual patient body part; and (e) a communication circuit configured to output the informational data.