Segmentectomy Versus Lobectomy for Deep Solid-Dominant Early-Stage NSCLC

Segmentectomy has been established as an accepted treatment option for selected small peripheral NSCLC, but high-level randomized evidence is limited for tumors located in the inner two-thirds of the lung parenchyma. Deep, solid-dominant nodules may have higher oncologic risk, more complex anatomy, and greater difficulty achieving conventional linear surgical margins. This trial evaluates whether standardized anatomic segmentectomy, including surgical quality control and lymph-node dissection requirements, is non-inferior to lobectomy for overall survival in patients with deeply located, solid-dominant, clinical stage IA NSCLC \<=2 cm. The trial incorporates centralized pre-randomization imaging review, mandatory recording of margin and surgical quality metrics, systematic or lobe-specific lymph-node dissection, independent endpoint adjudication, and DSMB safety and quality oversight. Participants randomized to the segmentectomy arm will undergo anatomic segmentectomy when feasible. Conversion to lobectomy is required for intraoperative frozen-section N1/N2 nodal metastasis and may occur for inadequate margins, anatomic difficulty, or safety concerns. Participants randomized to the lobectomy arm will undergo standard anatomic lobectomy. Intraoperative findings and final pathology do not change the original randomized assignment for the primary intention-to-treat analysis.