1. Institute of Biomedical Optics, University of Lübeck, Peter-Monnik-Weg 4, 23562 Lübeck, Germany
2. Por-Lab, Porphyrin-Laboratories GmbH, Blauenkrog 15, 23684 Scharbeutz, Germany
3. Department of Otorhinolaryngology, Clinic for ENT and HNS, University Hospital of Schleswig-Holstein, Campus Luübeck, Ratzeburger Allee 160, 23538 Luübeck, Germany