Final Report of NRG Oncology RTOG 0022: A Phase I/II Study of Conformal and Intensity.

BACKGROUND: XXXX XXXX XXXX XXXX (XXXX) XXXX was the first clinical trial evaluating multi-institution feasibility of IMRT for head and neck cancer. The primary endpoints of 2-year local-regional failure and reduction in acute xerostomia were reported previously. This report provides secondary endpoints with long-term follow-up.

METHODS: Eligibility included patients diagnosed with T1-2, N0-1 oropharyngeal cancer. Secondary endpoints included disease control and overall survival. Local-regional failure rates were estimated by the cumulative incidence method, and disease-free and overall survival rates were estimated by the Kaplan-Meier method. Late toxicities were graded by XXXX/EORTC criteria and are reported with descriptive statistics.

RESULTS: Sixty-seven of 69 enrolled patients were analyzed. Fifty patients (75%) had T2 disease and 38 (57%) were node negative (N0). Median follow-up was 11.9 years. Estimated 10-year local-regional failure, disease-free survival and overall survival rates were 15% (95%CI 8-25), 50% (95%CI 38-62) and 67% (95%CI 55-78), respectively. Highest reported late toxicities were: grade 5: 0%, grade 4: 9%, grade 3: 13%, and grade 2: 63%. Grade 3-4 late toxicities involved mucous membranes (7%), bone (4%), esophagus (4%), salivary gland (4%), pain (3%), weight loss (1%), and hemorrhage (1%). Grade 2-3 salivary gland toxicity was reported in 70% but improved over time. Forty-one (74.5%) and 17 (42.5%) of surviving patients had a toxicity assessment at > 5 years and >10 years, respectively.

CONCLUSIONS: This report of XXXX/XXXX XXXX, based on an early, prospectively collected dataset of head and neck IMRT treatments, provides benchmark long-term outcomes of this early version of the technology. At 10 years, 2/3 of patients were alive, with an acceptable level of grade 3-4 late toxicities.