A phase I/II study of altered fractionated imrt alone for intermediate t-stage oropharyngeal carcinoma

Background and Purpose: To prospectively assess the feasibility and efficacy of an accelerated and hyperfractionated intensity- modulated radiation therapy (IMRT) schedule for intermediate T-stage oropharyngeal cancer. Patients and Methods: Patients with T3 or unfavorable T2 oropharyngeal squamous cell carcinoma were eligible; a three-dose level simultaneous integrated boost IMRT strategy was used, delivering 78, 69, and 60 Gy to gross disease, high-risk and low-risk target areas, respectively, in 60 twice daily fractions over 6 weeks. No sequential/concomitant systemic treatment or up-front radical surgery was allowed. Median follow-up is 41.7 months (range: 3.5-80.8 months). Results: 25 patients were treated from 11/2002 to 11/2005. 92% of the individual fractions were delivered as scheduled. Grade 3 mucosal and skin toxicity was 100% and 72%, respectively, none of which persisted beyond 12 weeks; a percutaneous endoscopic gastrostomy tube was temporarily placed in 60% of patients. The estimated locoregional progression-free, distant metastases-free, and overall survival rates at 3 years were 86.3% ± 7.4%, 76.4% ± 9.6%, and 70.0% ± 9.6%, respectively. At the same time interval, the actuarial prevalence of grade 3+ CTCAE v3.0 toxicity was 26.1%. Conclusion: While the routine clinical use of this exploratory schedule is discouraged, it may represent the basis for future developments.