[1] Vrije Univ Amsterdam, Med Ctr, Dept Otolaryngol Head & Neck Surg, NL-1007 MB Amsterdam, Netherlands
[2] Netherlands Canc Inst, Div Psychosocial Res & Epidemiol, Amsterdam, Netherlands
[3] Vrije Univ Amsterdam, Med Ctr, Dept Clin Epidemiol & Biostat, NL-1007 MB Amsterdam, Netherlands
[4] Vrije Univ Amsterdam, Med Ctr, Dept Radiat Oncol, NL-1007 MB Amsterdam, Netherlands
[5] Univ Groningen, Univ Med Ctr Groningen, Dept Radiat Oncol, NL-9713 AV Groningen, Netherlands