This is a single-center, prospective, single-arm, open-label clinical trial evaluating the efficacy and safety of septum-guided segmentectomy in patients with 2-3 cm clinical stage IA3 peripheral non-small cell lung cancer (NSCLC) with a consolidation-to-tumor ratio (CTR) greater than 0.5 and up to 1.0. All eligible participants will undergo planned septum-guided anatomical segmentectomy or combined segmentectomy after intraoperative frozen-section confirmation of node-negative (N0) lymph node status. The primary endpoint is 3-year recurrence-free survival (RFS).
Age 18 to 80 years, male or female.
Clinical stage IA3 non-small cell lung cancer according to the International Association for the Study of Lung Cancer 9th edition tumor, node, metastasis classification; clinical T1cN0M0; tumor maximum diameter >2 cm and <=3 cm on imaging evaluation.
Consolidation-to-tumor ratio (CTR) >0.5 and <=1 on thin-section computed tomography.
Peripheral tumor judged by the investigator to be amenable to curative segmentectomy or lobectomy, with an anticipated ability to achieve the protocol-specified surgical margin.
Intraoperative lymph node frozen-section biopsy confirms N1 or N2 metastasis, or preoperative endobronchial ultrasound-guided biopsy or mediastinoscopy confirms N1, N2, or N3 metastasis, pleural dissemination, or distant metastasis. Patients with positive intraoperative frozen-section results will be converted to lobectomy plus systematic lymph node dissection as standard treatment and recorded as screen failures.
Multiple primary lung cancers or multiple pulmonary nodules requiring concurrent resection outside the protocol-defined scope that would affect assessment of the primary endpoint.
Prior ipsilateral lobectomy or segmentectomy, or severe pleural adhesions making the study procedure unevaluable.
Other active malignancy within 5 years, except cured low-risk tumors.