Oertel, Michael ; Elsayad, Khaled ; Elsayad, Khaled Abdelsalam Mohamed Shahereldin ; Kroeger, Kai ; Haverkamp, Uwe ; Haverkamp, U. ; Rudack, Claudia; Lenz, Georg ; Eich, Hans-Theodor ; Eich, Hans Theodor ; Eich, Hans Theodor ; Eich, Hans Theodor: Impact of radiation dose on local control and survival in extramedullary head and neck plasmacytoma