1. Radiotherapy Department, Interbalkan Medical Center, 10 Asclepioustr, 55535Pylaia, Thessaloniki, Greece
2. Advanced Radiation Oncology Department, IRCCS SacroCuore Don Calabria,Negrar-Verona, Italy
3. Clinic of Dentistry Hospital, Dental School, National and Kapodistrian University of Athens, 2 Thivonstr, Goudi, 11527Athens, Greece
4. Department of Otolaryngology, Faculty of Medicine, School of Health Sciences, University of Thessaly, University Hospital of Larissa, Biopolis,41110, Larissa, Greece
5. First Department of Otorhinolaryngology, Head and Neck Surgery, Hippocration Hospital, University of Athens, Athens, Greece
6. Radiation Oncology Department, GroupeHospitalierIntercommunal Le Raincy, Montfermeil, 10 Rue du GeneralLeclerc, 93370 Montfermeil, France
7. Medical Oncology, University of Ioannina, Ioannina, Greece
8. Oncology Clinic, Metaxa Hospital, Mpotasi 51, 18537Piraeus, Greece
9. National and Kapodistrian University of Athens, Medical School, 2nd Department of Radiology, Radiotherapy Unit, Attikon University Hospital, Athens, Greece
10. Oncology Department, General Military Hospital 401, 138 Mesogeion & Katechaki Avenue, 11525, Athens, Greece
11. Department of Radiotherapy, Faculty of Medicine, University of Thessaly, School of Health Sciences, Biopolis,41110, Larisa, Greece