1. Department of Radiation Oncology, Gustave Roussy, Villejuif, France
2. Department of Radiation Epidemiology, Unité 1018 INSERM, Gustave Roussy, Villejuif, France
3. Department of Head and Neck Oncology, Gustave Roussy, Villejuif, France
4. Department of Head and Neck Surgery, Gustave Roussy, Villejuif, France