Phase II study of twice-daily high-dose thoracic radiotherapy alternating with cisplatin and vindesine for unresectable stage III non-small-cell lung cancer: Japan Clinical Oncology Group Study 9306

Purpose: To evaluate the efficacy and toxicity of high-dose thoracic radiotherapy (TRT) alternating with chemotherapy (CH) for unresectable stage III non-small-cell lung cancer (NSCLC). Patients and Methods: Forty-one patients received TRT with 1.5 Gy twice daily, 5 days a week, on weeks 1, 2, 5, 6, and 9, up to a total dose of 66 to 72 Gy, alternating with cisplatin 80 mg/m² on day 1 and vindesine 3 mg/m² on days 1 and 8, repeated every 4 weeks, for two or three courses beginning on week 3. Results: The median (range) total dose of TRT and number of CH courses were 72 Gy (16.5 to 72 Gy) and three (zero to three), respectively. Delay in TRT ≥ 5 days was observed in 24 (75%) of 32 patients who completed the projected treatment, due to leukopenia in 12, esophagitis in seven, infection in two, and other causes in three patients. Partial responses were obtained in 36 patients (88%). The median survival time and 3- and 5-year survival rates were 18.4 months, 24%, and 10%, respectively. Grade 3 or 4 leukopenia and esophagitis developed in 32 and seven patients, respectively. Grade 3 or 4 late esophageal toxicity developed in two patients. Conclusion: Alternating high-dose TRT and CH for stage III NSCLC produced a high response rate with median and long-term survival comparable to prior trials utilizing standard approaches in this population. Acute and late esophageal toxicity was observed and interruption of TRT was required in most of the patients.