Randomization
METASTASIS
After eligibility has been confirmed, registration is performed using a web-based system at the JCOG Data Center. Patients are randomized to the standard arm (SIB56) or experimental arm (2-step40). Randomization is stratified according to the institution, presence or absence of lymph nodes metastasis, and the primary sites (oropharynx vs. hypopharynx vs. larynx).