Diagnostic performance of Node-RADS in assessing regional lymph node metastasis and prognosis in resected gastric cancer

Abstract

Objective To evaluate the diagnostic value of the preoperative CT-based Node Reporting and Data System (Node-RADS) score for lymph node metastasis (LNM) and its prognostic significance for disease-free survival (DFS) in NAC-naive, radically resected non-metastatic gastric cancer (GC, pTNM stage I–III), and to construct nomogram models for predicting LNM and DFS. Methods This retrospective study included NAC-naive GC patients who underwent radical gastrectomy with D2 lymphadenectomy between January 2019 and December 2022. Node-RADS scores were independently assessed by two radiologists. Logistic and Cox regression analyses were performed to identify independent predictors of LNM and DFS. Nomogram models were developed and evaluated using area under the curve (AUC), concordance index (C-index), calibration curves, and decision curve analysis. Results A total of 150 patients were included (median age 61 years). Pathological LNM was present in 72.7% of patients. Node-RADS scores were significantly associated with tumor size, CEA level, pTNM stage, N stage, and recurrence (all P < 0.05). Inter- and intra-observer agreement were good (κ = 0.746 and 0.798). Tumor size, CA19-9, and Node-RADS score were independent predictors of LNM. The LNM nomogram achieved an AUC of 0.88. During follow-up, 34.7% of patients developed recurrence, and Node-RADS score was significantly associated with DFS. Conclusion Preoperative CT-based Node-RADS scoring shows good diagnostic and prognostic value in gastric cancer and may assist in preoperative risk stratification.