Dose-Escalation Study of Three-Dimensional Conformal Thoracic Radiotherapy With Concurrent S-1 and Cisplatin for Inoperable Stage III Non–Small-Cell Lung Cancer

PurposeTo determine the recommended dose (RD) in concurrent conformal radiotherapy with S-1 and cisplatin chemotherapy for inoperable stage III non–small-cell lung cancer.Patients and MethodsEligible patients with inoperable stage III non–small-cell lung cancer, age ≥ 20 years, performance status 0-1 received 4 cycles of intravenous cisplatin (60 mg/m2, day 1) and oral S-1 (80, 100, or 120 mg based on body surface area, days 1-14) repeated every 4 weeks. Radiation doses were 66, 70, and 74 Gy for arms 1, 2, and 3, respectively.ResultsA total of 24 patients were enrolled in our study, including 6 in arm 1, 6 in arm 2, and 12 in arm 3. The patients consisted of 14 men and 10 women, with a median age of 63 years (range, 44-73 years). The median follow-up was 27.3 months (range, 8.5-42.6 months) for all patients and 33.9 months (range, 15.2-42.6 months) for those still alive. Grade 3 febrile neutropenia, lung toxicities, and heart toxicities occurred in 2, 2, and 2 patients, respectively. Dose-limiting toxicity occurred in 2, none, and 1 patient in arms 1, 2, and 3, respectively. The median survival was not reached, and the 2-year survival rate was 70% (95% CI, 51%-89%). Two-year local relapse-free survival and distant metastasis–free survival were 74% (95% CI, 56%-92%) and 45% (95% CI, 25%-65%), respectively.ConclusionsHigh-dose radiotherapy with S-1 and cisplatin is feasible, and 74 Gy was determined as the recommended dose.