[1] Norwegian Radium Hosp, Dept Radiotherapy & Oncol, N-0310 Oslo, Norway
[2] Natl Hosp Norway, Rikshosp, Dept Otolaryngol, Oslo, Norway
[3] Univ Trondheim Hosp, Dept Oncol, N-7006 Trondheim, Norway
[4] Univ Trondheim, Fac Med, Unit Appl Clin Res, Trondheim, Norway
[5] Sahlgrens Univ Hosp, Dept Otolaryngol Head & Neck Surg, S-41345 Gothenburg, Sweden
[6] Malmo Univ Hosp, Dept Otorhinolaryngol, Malmo, Sweden
[7] Univ Lund Hosp, Dept Otorhinolaryngol, S-22185 Lund, Sweden
[8] Univ Utrecht Hosp, Dept Internal Med, Utrecht, Netherlands
[9] Univ Utrecht Hosp, Dept Nursing Sci, Utrecht, Netherlands
[10] MRC, Canc Trials Off, Cambridge, England