[1] Norwegian Radium Hosp, Dept Radiotherapy & Oncol, N-0310 Oslo, Norway
[2] Univ Utrecht, Med Ctr, Utrecht, Netherlands
[3] Univ Trondheim Hosp, Trondheim, Norway
[4] Sahlgrens Univ Hosp, S-41345 Gothenburg, Sweden
[5] EORTC Data Ctr, Brussels, Belgium
[6] Malmo Univ Hosp, Malmo, Sweden
[7] Mt Vernon Hosp, Northwood HA6 2RN, Middx, England
[8] Marie Sklodowska Curie Mem Canc Ctr, Warsaw, Poland
[9] Inst Jules Bordet, B-1000 Brussels, Belgium
[10] Univ Helsinki, Cent Hosp, Dept Maxillofacial Surg, Helsinki, Finland
[11] McGill Univ, Montreal, PQ, Canada
[12] Green Lane Hosp, Auckland 3, New Zealand
[13] Hop Adultes Timone, Marseille, France
[14] Univ Spital Zurich, Inst Radioonkol, Zurich, Switzerland