A radio-pathologic integrated model for prediction of lymph node metastasis stage in patients with gastric cancer

Background Accurate prediction of lymph node metastasis stage (LNMs) facilitates precision therapy for gastric cancer. We aimed to develop and validate a deep learning-based radio-pathologic model to predict the LNM stage in patients with gastric cancer by integrating CT images and histopathological whole-slide images (WSIs). Methods A total of 252 patients were enrolled and randomly divided into a training set ( n = 202) and a testing set ( n = 50). Both pretreatment contrast-enhanced abdominal CT and WSI of biopsy specimens were collected for each patient. The deep radiologic and pathologic features were extracted from CT and WSI using ResNet-50 and Vision Transformer (ViT) network, respectively. By fusing both radiologic and pathologic features, a radio-pathologic integrated model was constructed to predict the five LNM stages. For comparison, four single-modality models using CT images or WSIs were also constructed, respectively. All models were trained on the training set and validated on the testing set. Results The radio-pathologic integrated mode achieved an overall accuracy of 84.0% and a kappa coefficient of 0.795 on the testing set. The areas under the curves (AUCs) of the integrated model in predicting the five LNM stages were 0.978 (95% Confidence Interval (CI 0.917–1.000), 0.946 (95% CI 0.867–1.000), 0.890 (95% CI 0.718–1.000), 0.971 (95% CI 0.920–1.000), and 0.982 (95% CI 0.911–1.000), respectively. Moreover, the integrated model achieved an AUC of 0.978 (95% CI 0.912–1.000) in predicting the binary status of nodal metastasis. Conclusion Our study suggests that radio-pathologic integrated model that combined both macroscale radiologic image and microscale pathologic image can better predict lymph node metastasis stage in patients with gastric cancer. Graphical abstract