1. From the Institut Gustave Roussy, Radiation Oncology, Head and Neck Statistics Departments, Villejuif; Centre Alexis Vautrin, Nancy; Centre Jean Perrin, Clermont-Ferrand; Centre Claudius Regaud, Toulouse; Centre René Gauducheau, Nantes; Centre Francois Baclesse, Caen; Centre Hospitalier, Lagny; and the Centre Val D'aurelle, Montpellier, France