1. Department of Urology, St. Elisabeth–Hospital Straubing, Straubing, Germany.
2. Department of Urology, University of Regensburg, Caritas-Krankenhaus St. Josef, Regensburg, Germany.
3. Department of Urology, Ruppiner Kliniken Neuruppin, Neuruppin, Germany.
4. Department of Urology, Ludwig-Maximilians-University of Munich, Munich, Germany.