[1] Clin Univ St Luc, B-1200 Brussels, Belgium
[2] NN Blokhin Russian Canc Res Ctr, Moscow, Russia
[3] Zala Megyei Korhaz, Onkol Osztaly Kulsokorhaz, Zalaegerszeg Pozva, Hungary
[4] Semmelweis Univ, Dept Ear Nose & Throat Head & Neck Surg, Budapest, Hungary
[5] Kursk Reg Oncol Dispensary, Kursk, Russia
[6] Genmab, Copenhagen, Denmark
[7] Katholieke Univ Leuven Hosp, Leuven Canc Inst, Louvain, Belgium