Phase II Trial of SFRT Plus Chemo-immunotherapy for LA-NSCLC With Suboptimal Neoadjuvant Response

Lattice radiation therapy (LRT) is a spatially fractionated thoracic radiotherapy technique that creates alternating high- and low-dose regions within primary lung tumors and metastatic lymph nodes to strengthen local tumor suppression and reduce radiation injury to normal thoracic organs. This study aims to evaluate the efficacy and safety of combining LRT with consolidation chemoimmunotherapy in unresectable stage III LA-NSCLC patients who show suboptimal tumor response to prior neoadjuvant chemoimmunotherapy, through a single-arm Phase II clinical trial. Patients will receive thoracic LRT delivered by a medical linear accelerator. High-dose spherical sub-targets will be contoured within the gross tumor volume of primary lung lesions and regional nodal metastases under standardized dose constraints to spare the lung, heart and esophagus. All enrolled subjects will receive sequential consolidation chemoimmunotherapy administered within one week after finishing LRT. Tumor response, treatment-related adverse events, local tumor control and long-term survival outcomes will be prospectively tracked throughout treatment and long-term follow-up.