In January of 1985, Fr. Dimitrios was appointed to serve concurrently as the Executive Director of the newly-founded [[Orthodox Christian Mission Center|Archdiocesen Mission Center]]. Initially based at the St. Photios Shrine, Fr. Dimitrios, oversaw the construction of a new facility for the Mission Center and initiated key programs, including the sending forth of the first Orthodox mission teams to Africa.

On May 18, 1998, the [[Holy Synod]] of the Ecumenical Patriarchate of Constantinople unanimously elected Fr. Dimitrios as an auxilliary bishop to Archbishop Spyridon of America with the title Bishop of Xanthos. The new Bishop was consecrated to the episcopacy on May 31, 1998, at the [[Greek Orthodox Cathedral of St. George]] in Philadelphia by Archbishop Spyridon, [[Paisios (Loulourgas) of Tyana|Metropolitan Paisios of Tyana]], [[Philotheos (Karamitsos) of Meloa|Bishop Philotheos of Meloa]], and [[Vikentios (Malamatenios) of Apameia|Bishop Vikentios of Apameia]].