1. Department of Oncology, Radiation Oncology, University of Turin, Turin - Italy
2. Radiation Oncology, Ospedale Sacro Cuore-Don Calabria, Negrar (Verona) - Italy
3. Department of Oncology, Proton Therapy Unit, Azienda Provinciale per i Servizi Sanitari (APSS), Trento - Italy
4. Radiotherapy Unit, Campus Bio-Medico University, Rome - Italy
5. Radiation Oncology Department-Gemelli ART, Sacred Heart Catholic University, Rome - Italy
6. Department of Radio-Oncology, IRCCS AOU San Martino IST, National Institute for Cancer Research, Genoa - Italy
7. Department of Radiation Oncology, Regional Oncological Hospital, Cagliari - Italy
8. Department of Sensory Organs, Institute of Otorhinolaryngology, Audiology and Phoniatrics, Sapienza University, Rome - Italy
9. Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Center, Rozzano (Milan) - Italy
10. Department of Sperimental and Clinical Biomedical Sciences, Radiation Oncology, AOU Careggi, Florence - Italy
11. Radiation Oncology Department, ARNAS Civico Hospital, Palermo - Italy
12. Radiotherapy Department, University Hospital ‘Maggiore della Carità,’ Novara - Italy
13. Radiotherapy Department, Centro REM, Catania - Italy