Postoperative accelerated radiotherapy in high-risk squamous cell carcinoma of the head and neck: long-term results of a prospective trial.

Background: For patients treated with combination resection and postoperative radiotherapy, the interval between surgery and completion of radiotherapy represents an opportunity for tumor repopulation and treatment failure. A prospective trial to test the feasibility and efficacy of accelerated postoperative radiotherapy was concluded in August of 1990.

Methods: Thirty-two patients with high-risk pathologic findings were treated with 63 Gy in 35 fractions of 1.8 Gy over 5.2 weeks using a modified concomitant-boost technique.

Results: Acute mucosal and skin reactions were increased but tolerable. At a median follow-up of 6 years, the crude in-field recurrence rate for the entire group was 10/32 (31%), with 0/10 (0%) recurrences in patients commencing accelerated radiotherapy within 4 weeks of surgery and 10/22 (45%) recurrences in patients with a delay of more than 4 weeks (p = .006). The rate of late complications appears similar to that seen with conventional radiotherapy, with possibly a higher rate of "consequential"-type late effects.

Conclusions: This pilot study suggests that prompt application of accelerated postoperative radiotherapy significantly improves local-regional control and supports the concept of rapid tumor repopulation in the postoperative setting. Various strategies to overcome tumor repopulation are discussed.