Tobias Bolling1
, Andreas Schuck2
, Hildegard Pape3
, Christian Rube4
, Barbara Pollinger5
, Beate Timmermann6
, Rolf D Kortmann7
, Karin Dieckmann8
and Normann Willich1 
1
Department of Radiotherapy, University Hospital of Münster, Germany
2
Radiotherapy Facility, Memmingen, Germany
3
Department of Radiotherapy, University Hospital of Düsseldorf, Germany
4
Department of Radiotherapy, University Hospital of Homburg/Saar, Germany
5
Department of Radiotherapy, University Hospital of Munich, Germany
6
Department of Radiotherapy of the Paul-Scherrer-Institute, Villigen, Switzerland
7
Department of Radiotherapy, University Hospital of Leipzig, Germany
8
Department of Radiotherapy, University Hospital of Vienna, Austria