[1] Interbalkan Med Ctr, Radiotherapy Dept, 10 Asclepioustr, Thessaloniki 57001, Greece
[2] Natl & Kapodistrian Univ Athens, Clin Hosp Dent, Dent Sch, 2 Thivonstr, Athens 11527, Greece
[3] Univ Brescia, Adv Radiat Oncol Dept, IRCCS SacroCuore Don Calabria Hosp, Brescia, Italy
[4] Gen Mil Hosp 401, Oncol Dept, 138 Ave Mesoge & Katechaki, Athens 11525, Greece
[5] Jordanian Royal Med Serv, Radiat Oncol Dept, Med Ctr, King Abdullah II St 230, Amman, Jordan
[6] Metaxa Hosp, Oncol Clin, Mpotasi 51, Piraeus 18537, Greece
[7] Semmelweis Univ, Ctr Radiotherapy, Natl Inst Oncol, Dept Oncol, Budapest, Hungary
[8] Univ Thessaly, Univ Hosp Larissa, Fac Med, Sch Hlth Sci,Dept Otolaryngol, Larisa 41110, Greece
[9] Univ Athens, Hippocrat Hosp, Dept Otorhinolaryngol Head & Neck Surg 1, Athens, Greece
[10] Univ Hosp Larisa, Dept Radiotherapy, Larisa 41110, Greece
[11] Univ Ioannina, Med Oncol, Ioannina, Greece
[12] Grp Hosp Intercommunal Le Raincy, Radiat Oncol Dept, 10 Rue Gen Leclerc, F-93370 Montfermeil, France
[13] Univ Thessaly, Fac Med, Sch Hlth Sci, Dept Radiotherapy, Larisa 41110, Greece