The Doctor never returned to Susan in the television series, although they did meet again on Gallifrey in "The Five Doctors".
The problem is that the Eighth Doctor was reunited with Susan in two totally incompatible ways. One was in "Legacy of the Daleks" (BBC Eighth Doctor Adventures novel). The other was in "An Earthly Child" (Big Finish audio story). As stated there is no way to reconcile these two stories.