[1] Katholieke Univ Leuven, Dept Oncol, Lab Expt Radiotherapy, B-3000 Leuven, Belgium
[2] Univ Ziekenhuis Leuven, Leuven Canc Inst, Dept Oncol, B-3000 Leuven, Belgium
[3] Univ Melbourne, Dept Radiat Oncol, Austin Hlth, Melbourne, Vic 3000, Australia
[4] Univ Melbourne, Dept Radiat Oncol, Div Med, St Vincents Hosp, Melbourne, Vic 3000, Australia
[5] Univ Michigan, Dept Radiat Oncol, Ann Arbor, MI 48109 USA
[6] Univ Florida, Coll Med, Dept Radiat Oncol, Gainesville, FL 32209 USA
[7] Prince Wales Canc Ctr, Dept Radiat Oncol, Sydney, NSW 2031, Australia
[8] Univ Ljubljana, Inst Oncol, Dept Radiat Oncol, Ljubljana 1000, Slovenia
[9] Univ Hong Kong, Li Ka Shing Fac Med, Dept Clin Oncol, Hong Kong, Peoples R China
[10] Int Head & Neck Sci Grp, I-35125 Padua, Italy