1. Department of Radiation Oncology; Tenon Hospital, Assistance Publique - Hôpitaux Universitaires Paris Est; University Pierre et Marie Curie Paris VI; Paris France
2. Department of Radiation Oncology; Georges Pompidou Hospital; Assistance Publique - Hôpitaux de Paris, University Paris V; Paris France
3. Department of Radiation Oncology; Pitié-Salpêtrière Hospital; Assistance Publique - Hôpitaux de Paris; University Paris VI; Paris France
4. Departement of Otorhinolaryngology and Head and Neck Surgery; Tenon Hospital; Assistance Publique - Hôpitaux de Paris; Cancerest, University Paris VI; Paris France