Aim: The feasibility and improved efficacy of six conventional fractions per week has previously been proven in a Danish randomized trial. We tested the tolerance and efficacy of seven conventional fractions per week using a concomitant boost technique.
Methods: From September 1996 to May 1998, 20 patients with squamous cancer of the head and neck were treated with radiation alone. The site of disease was oropharynx in 35%, larynx in 30%, oral cavity 20%, and hypopharynx in 15%. All patients had stage III (10%)/IV (90%) disease. The planned total dose to gross disease was 66 Gy delivered in 33 fractions of 2 Gy each in 31 days. Large volumes were treated to 46 Gy, 2 Gy per fraction, once each morning, Monday-Friday. Boosts to gross disease consisted of 20 Gy in 10 fractions > or = 6 h after the morning dose on Tuesday and Thursday.
Results: Acute toxicity > or = grade 3 was mucous membrane 75%, pharynx 60%, skin 65%, and larynx 35%. One acute toxicity was fatal. Chronic toxicity > or = grade 3 (three patients) was mucous membrane 5%, pharynx 10%, skin 5%, salivary 15%, and larynx 5%. All patients with grade III or greater late toxicity had grade III acute toxicity in each toxicity category. At 30 months Kaplan-Meier survival is 55%, and local control is 39%.
Conclusions: Without increasing resource utilization this scheme accelerates treatment by 30%. As expected acute toxicity is high but manageable. Chronic toxicity appears comparable to other altered fractionation strategies however the median follow up is only 30 months more toxicity may emerge as the data matures. We plan further trials using 1.8 Gy fractions to reduce toxicity.