[1] Katharinen Hosp, Dept Otorhinolaryngol Head & Neck Surg, Kriegsbergstr 60, D-70174 Stuttgart, Germany
[2] Lausanne Univ Hosp, Serv Otorhinolaryngol, Airway Unit, Lausanne, Switzerland
[3] G Gaslini Childrens Hosp, Dept Pediat Surg, Genoa, Italy
[4] Univ Tubingen, Dept Radiol, Nucl Med Unit, Hoppe Seyler Str 3, D-72076 Tubingen, Germany
[5] Univ Genoa, Dept Internal Med, Genoa, Italy
[6] Univ Milan, Natl Canc Inst Milan, Fdn IRCCS, Dept Otorhinolaryngol Maxillofacial & Thyroid Sur, Milan, Italy
[7] Univ Genoa, IRCCS Osped Policlin San Martino, Dept Otorhinolaryngol Head & Neck Surg, Largo R Benzi 10, I-16132 Genoa, Italy