Hyperfractionated radiation therapy for oropharyngeal carcinoma in a Japanese population.

Background: Hyperfractionated radiation therapy is recognized to be a better treatment method, especially regarding local control, than conventional radiation therapy for oropharyngeal carcinoma. However, the survival benefit of hyperfractionated radiation therapy for oropharyngeal carcinoma has not been reported so far. Moreover, patient populations of previous studies were mostly white or African-American, and rarely included Orientals. Thus, the current study is designed to evaluate not only local control but the survival benefit of hyperfractionated radiation therapy for oropharyngeal carcinoma in a Japanese population. Methods: The eligibility criteria were as follows. The patients were 20 years or older. Performance status ranged from 0 to 2. No patient with double carcinoma was included except those with superficial esophageal carcinoma or advanced carcinoma controlled for at least 2 years after treatment. In our radiation protocol, hyperfractionated radiation therapy was adopted using 1.2 Gy per fraction, two fractions per day (6 h apart), 5 days a week, for a total dose of 66 Gy or more. Results: Complete response was achieved in all 14 patients with oropharyngeal lesions. In five patients with lymph node metastasis, complete response was achieved in four patients and partial response was achieved in the remaining one. The 3-year loco-regional control rate was 77% and the 3-year overall survival rate was 69%. Conclusions: Treatment with hyperfractionated radiation therapy is considered superior to conventional radiation therapy with acceptable toxicity for Japanese patients with oropharyngeal carcinoma in terms of loco-regional control rate and overall survival rate.