1049 - Hypofractionated Intensity-Modulated Radiotherapy for Unresectable Non-Small Cell Lung Cancer: Preliminary Results of a Prospective Phase II Study
Presenter(s)
Q. Liu1, Y. Gao2, and A. Shi3; 1Department of Radiation Oncology, Beijing Luhe Hospital, Beijing, China, 2The Department of Radiotherapy, Beijing Luhe Hospital,Capital Medical University, Beijing, China, Beijing, Beijing, China, 3Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Radiation Oncology, Peking University Cancer Hospital & Institute, Beijing, China
Purpose/Objective(s): To evaluate survival outcomes, local and distant control, and toxicity in patients with unresectable, locally advanced non-small cell lung cancer (NSCLC) treated with radical hypofractionated radiation therapy.
Materials/Methods: Between October 2021 and December 2024, 48 patients with unresectable stage III/IVa NSCLC were enrolled. Patients received hypofractionated intensity-modulated radiation therapy (SIB-VMAT), delivering 60 Gy (3-4 Gy per fraction) to the primary tumor and regional metastatic lymph nodes. The primary endpoint was the incidence of acute toxicities, including radiation pneumonitis, radiation esophagitis, and bone marrow suppression. Secondary endpoints included 1-year and 2-year overall survival (OS) rates, as well as 1-year and 2-year progression-free survival (PFS) rates.
Results: During a median follow-up of 20 months (95% confidence interval [CI], 18–29 months), the median OS was not reached, while the median PFS was 23 months (95% CI, 12–33 months). The 1-year and 2-year OS rates were 75.7% and 67.1%, respectively. The 1-year and 2-year PFS rates were 70.4% and 50%, respectively. The 1-year and 2-year cancer-specific survival (CSS) rates were 83% and 77%, respectively. Isolated locoregional recurrence occurred in 8.3% of patients (n=4). The incidence of grade 3 (G3) or higher treatment-related lung toxicity was 14.6% (n=7) . Additionally, 8.3% of patients (n=4) experienced G3 radiation esophagitis, with no cases of esophageal perforation.
Conclusion: Hypofractionated intensity-modulated radiation therapy (hypo-IMRT) demonstrates promising clinical efficacy with tolerable toxicity in patients with unresectable stage III/IVa locally advanced NSCLC, under controlled conditions. However, caution is advised when increasing the radiation dose, and follow-up at 3 or 6 months post-radiotherapy is crucial for the early detection and management of potential adverse effects.