1. Department of Head & Neck Medical Oncology 3, Fondazione IRCCS Istituto Nazionale dei Tumori, Via Venezian 1, Milan, 20133, Italy
2. Department of Oncology & Hemato-Oncology, University of Milan, Via Santa Sofia 9/1, Milan, 20122, Italy
3. Radiation Oncology Unit, Clinical Department, CNAO National Center for Oncological Hadrontherapy, Via E. Borloni 1, Pavia, 27100, Italy
4. Department of Internal Medicine & Medical Therapy, University of Pavia, Via Aselli 43/45, Pavia, 27100, Italy
5. Radiobiology Unit, Research and Development Department, CNAO National Center for Oncological Hadrontherapy, Via E. Borloni 1, Pavia, 27100, Italy
6. Scientific Direction, CNAO National Center for Oncological Hadrontherapy, Via E. Borloni 1, Pavia, 27100, Italy
7. SSD Biostatistica & Clinical Trial Center Service of Biometry and Statistics, Fondazione IRCCS Policlinico San Matteo, Viale Golgi 19, Pavia, 27100, Italy
8. Medical Physics, Clinical Department, CNAO National Center for Oncological Hadrontherapy, Via E. Borloni 1, Pavia, 27100, Italy
9. Department of Medical Oncology, Fondazione IRCCS Policlinico San Matteo, Viale Golgi 19, Pavia, 27100, Italy
10. Department of Medical Oncology 1, Fondazione IRCCS Istituto Nazionale dei Tumori, Via Venezian 1, Milan, 20133, Italy
11. Department of Biophysics, GSI Helmholtz Center for Heavy Ion Research, Darmstadt, 64291, Germany