[1] Mem Sloan Kettering Canc Ctr, Head & Neck Serv, Dept Surg, New York, NY 10021 USA
[2] Prince Wales Hosp, Dept Surg, Sydney, NSW, Australia
[3] Ist Nazl Tumori, Dept Surg, I-20133 Milan, Italy
[4] Royal Natl Throat Nose & Ear Hosp, Dept Surg, London WC1X 8DA, England
[5] Ist Nazl Tumori, Dept Surg, Rio De Janeiro, Brazil
[6] Royal Natl Throat Nose & Ear Hosp, Dept Surg, London WC1X 8DA, England
[7] Inst Nacl Canc, Dept Surg, Rio De Janeiro, Brazil
[8] Univ Calif Davis, Med Ctr, Dept Surg, Sacramento, CA 95817 USA
[9] Tel Aviv Sourasky Med Ctr, Dept Surg, Tel Aviv, Israel
[10] Toronto Gen Hosp, Dept Surg, Toronto, ON, Canada
[11] Massachusetts Eye & Ear Infirm, Dept Surg, Boston, MA 02114 USA
[12] Canc Inst Hosp, Dept Surg, Tokyo, Japan
[13] Hosp Canc AC Camargo, Dept Surg, Sao Paulo, Brazil
[14] Univ Virginia, Hlth Syst, Dept Surg, Charlottesville, VA USA
[15] Hosp Clin Sao Paulo, Dept Surg, Sao Paulo, Brazil
[16] Tata Mem Hosp, Dept Surg, Bombay 400012, Maharashtra, India
[17] Ctr Head Neck Surg, Dept Surg, Denver, CO USA
[18] Univ Pittsburgh, Dept Surg, Pittsburgh, PA USA
[19] Univ Hong Kong, Dept Surg, Hong Kong, Hong Kong, Peoples R China