Split-course accelerated hyperfractionation radiotherapy for advanced head and neck cancer: influence of split time and overall treatment time on local control.

We analyzed 52 patients with stage III and IV head and neck cancer who were given split-course accelerated hyperfractionated radiotherapy with curative intent, focusing particularly on the influence of split-time on local control. An initial complete response was achieved in 16 patients (31%), and the rate of persistent local control at 3 years was 23%. The cause specific survival rate at 3 years was 29%. Univariate analysis of local control according to the split-time duration and overall treatment time showed that shorter duration (< or = 14 days or < or = 45 days, respectively) had a significantly positive impact on local control (P < 0.05). Multivariate analysis using local control as an endpoint also demonstrated that gender (women showing a better outcome than men) and split-time (< or = 14 days was better than > 14 days) were statistically significant factors for local control. These results suggest that shortening the split-time during radiotherapy might improve local control in accelerated hyperfractionation.