[1] Univ Amsterdam, Dept Otolaryngol Head & Neck Surg, Med Ctr, Amsterdam, Netherlands
[2] Vrije Univ Amsterdam, Amsterdam Univ, Dept Epidemiol & Biostat, Amsterdam Publ Hlth,Med Ctr, Amsterdam, Netherlands
[3] Vrije Univ Amsterdam, Amsterdam Univ, Canc Ctr Amsterdam, Dept Med Oncol,Med Ctr, Amsterdam, Netherlands
[4] Univ Groningen, Univ Med Ctr Groningen, Dept Radiat Oncol, Groningen, Netherlands
[5] Univ Amsterdam, Dept Radiat Oncol, Med Ctr, Amsterdam, Netherlands
[6] Univ Amsterdam, Dept Med Oncol, Med Ctr, Amsterdam, Netherlands