Preoperative 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT)-based strategy for predicting negative mediastinal lymph node metastasis status in non-small cell lung cancer

Background: F-FDG PET/CT) is standard for detecting mediastinal lymph node (MLN) metastasis staging in non-small cell lung cancer (NSCLC). However, in the era of minimally invasive surgery, identifying low-risk patients is equally vital. We aimed to develop a PET/CT-based strategy to identify an East Asian cohort at minimal risk of MLN metastasis who could potentially be spared invasive staging. Methods: F-FDG PET/CT and curative surgical resection with systematic lymph node dissection from January 2008 and March 2024 were retrospectively analyzed. Pathological nodal status served as the reference standard. Metabolic and morphological features were identified using preoperative high-resolution CT with PET/CT scans. Results: Among 2,414 patients, 186 (7.70%) with ground-glass opacity (GGO)-predominant tumors had no MLN metastasis. Among 2,228 (92.29%) patients with solid-predominant tumors, multivariate logistic regression identified N2 lymph node enlargement on CT, pure-solid tumor and MLN maximum standard uptake value (SUVmax) as independent predictors of pN2 status. Multivariate logistic regression model based on preoperative PET/CT metrics achieved an area under the curve (AUC) of 0.7521. Conclusions: For patients presenting with GGO-predominant subsolid nodules, unnecessary PET/CT scans can be omitted to prevent over-diagnosis and excessive surgical intervention. Based on clinical characteristics of cT1 tumors, we propose a preliminary strategy for identifying patients with minimal MLN metastasis risk using PET/CT metrics, laying groundwork for prospective validation.