Primary tumor survey/follow-up
All patients routinely received a standard work-up, including medical history submission, comprehensive physical examination, and endoscopic examinations of the pharynx and larynx during initial staging and follow-up after treatment. Patients underwent follow-up every month during the first year, every 2 months in the second year, every 3 months in the third year, and every 6 months thereafter. Computed tomography and/or magnetic resonance imaging of the head and neck was carried out every 6 to 12 months up to the second year and every two years thereafter.