 Eligible patients admitted from March 1999 to December 2000 were treated with conventionally fractionated radiotherapy. These patients represented the retrospective part of the study. Patients admitted between January 2001 and June 2004 were included in the prospective part of the study. Following the confirmation of their eligibility, altered fractionation schedule assignment was made after stratifying by site of origin larynx vs oropharynx vs hypopharynx, Karnofsky performance score 60-70 vs 80-100, and stage of disease I and II vs III and IV. Patients were randomized to receive radiotherapy delivered using either hyperfractionation or accelerated fractionation with concomitant boost as a late accelerating component. Exceptions occurred when patients either refused treatment with two daily fractions or were not offered twice-a-day irradiation because of lack of machine time. 