Hypofractionated Intensity Modulated Radiation Therapy With Concurrent Chemotherapy in Locally Advanced Non-Small Cell Lung Cancer: A Phase II Prospective Clinical Trial (GAST01011)

Purpose: We aimed to explore the efficacy and toxicity of split-course hypofractionated radiation therapy with concurrent chemotherapy (HRT-CHT) in patients with locally advanced non-small cell lung cancer (LANSCLC) in this single-arm, phase II study. Methods and Materials: Patients with LANSCLC were considered eligible if their forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC%) and carbon monoxide diffusing capacity (DLCO%) were >= 40% and >= 45%, respectively. HRT-CHT using the intensity modulated radiation therapy technique was administered with 51 Gy in 17 fractions as the first course followed by a break. Patients without disease progression or persistent >= grade 2 toxicities had an HRT CHT of 15 to 18 Gy in 5 to 6 fractions as a boost. The primary endpoint was progression-free survival, and the secondary endpoint was overall survival (OS). Results: Eighty-nine patients were enrolled and analyzed. The median follow-up was 29.5 months for all patients and 35.3 months for the survivors. The objective response rate was 97.8%; the median progression-free survival and OS were 11.0 and 27.0 months, respectively. Grade 3 acute esophagitis/pneumonitis occurred in 15 (16.9%)/7 (7.9%) patients. Grade 3/5 late pneumonitis occurred in 2 (2.2%)/1 (1.1%) patients. Of the 78 (87.6%) who completed the split-course HRT-CHT per protocol, patients with better FEV1/FVC% and DLCO% after the break had significantly better OS (for the FEV/FVC1% >= 80% vs 60%-79% vs 41%-59% groups, 2-year OS values were 57.2% vs 56.9% vs 0%, respectively, P = .024; for the DLCO% >= 80% vs 60%-79% vs 45%-59% groups, 2-year OS values were 70.4% vs 48.4% vs 37.5%, respectively, P = .049). Conclusions: Split-course HRT-CHT achieved a promising response rate and survival with tolerable toxicity in LANSCLC. Pulmonary function tests are necessary indicators for radiation treatment planning and dose escalation. (C) 2021 Published by Elsevier Inc. on behalf of American Society for Radiation Oncology.