[1] Univ Sao Paulo, Hosp Siriolibanes, Dept Radiat Oncol, Sao Paulo, Brazil
[2] Univ Sao Paulo, Fac Med, Inst Canc Estado Sao Paulo, Sao Paulo, Brazil
[3] Univ Fed Sao Paulo, Escola Paulista Med UNIFESP EPM, Brazilian Cochrane Ctr, Sao Paulo, Brazil
[4] Univ Fed Sao Paulo, Escola Paulista Med UNIFESP EPM, Discipline Emergency Med & Evidence Based Med, Sao Paulo, Brazil
[5] Harvard Univ, Sch Med, Dana Farber Canc Inst, Dept Med Oncol, 44 Binney St, Boston, MA 02115 USA
[6] Brigham & Womens Hosp, Dept Med, 75 Francis St, Boston, MA 02115 USA
[7] Univ Calif San Diego, La Jolla, CA 92093 USA
[8] Harvard Univ, Sch Med, Dana Farber Canc Inst, Head & Neck Oncol Program, 44 Binney St, Boston, MA 02115 USA
[9] AC Camargo Canc Ctr, Dept Head & Neck Surg & Otorhinolaryngol, Sao Paulo, Brazil