1. Department of Otorhinolaryngology Head and Neck Surgery, Elbe Klinikum Stade, Stade, Germany
2. Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Centre Mannheim, Mannheim, Germany
3. Department of Otorhinolaryngology, Head and Neck Surgery, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institutes of Health, Berlin, Germany
4. Diagnostic and Interventional Radiology, Dr. Hancken Clinic, Stade, Germany