1. Department of Urology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany;
2. Department of Urology, University of Duisburg-Essen, Essen, Germany;
3. Department of Urology, Heinrich-Heine-University, Duesseldorf, Germany;
4. Cologne University, Cologne, Germany;
5. Department of Urology, Klinikum Kassel, Kassel, Germany;
6. Department of Urology, Paracelsus Klinik Golzheim, Duesseldorf, Germany;
7. Department of Urology, Staedtisches Klinikum Karlsruhe, Karlsruhe, Germany;
8. Department of Urology, University Hospital Ulm, Germany, Ulm, Germany;
9. Department of Urology, Klinikum Fulda, Fulda, Germany;
10. Saarland University Hospitals, Homburg/Saar, Germany;
11. Department of Urology, University Hospital Tuebingen, Eberhard-Karls University, Tuebingen, Germany;
12. Department of Urology, Klinikum Ludwigshafen, Ludwigshafen, Germany;
13. Department of Urology, University of Magdeburg, Magdeburg, Germany;
14. Department of Urology, Staedtische Kliniken Dortmund, Dortmund, Germany;
15. Department of Urology, University Witten/Herdecke, Wuppertal, Germany;
16. Department of Urology, Kliniken der Stadt Koeln, Krankenhaus Holweide, Cologne, Germany;