To develop an individualized nomogram based on contrast-enhanced CT for adjuvant diagnosis of the status of Epstein-Barr virus(EBV) in gastric cancer.

A retrospective analysis was conducted on the clinical and CT data of gastric cancer patients at the First Affiliated Hospital of Zhengzhou University, who were confirmed to have EBV status by gross pathological histology from December 2016 to December 2023. The patients were divided into the EBV-positive group (n=36) and the EBV-negative group (n=95). Two radiologists assessed qualitative and quantitative features of lesions on the enhanced CT. Consistency of the quantitative data was evaluated using Bland-Altman tests. Univariate and multivariate logistic regression were used to screen out independent predictive factors and establish a combined model, which was then visualized using a nomogram. Discriminative ability of the nomogram and individual predictors was assessed using the area under the curve (AUC) of the receiver operating characteristic (ROC) curve, and the differences in AUC values were compared using the DeLong test.

Good consistency was found between the two radiologists' measurements using the Bland-Altman analysis. The ratio of arterial phase lesion CT value to abdominal aorta CT value (Ra), enhancement homogeneity, and maximum tumor length were identified as independent predictors for predicting the EBV expression status of gastric cancer before surgery. Their AUC values were 0.620, 0.722, and 0.713, respectively. The nomogram combining these factors had an AUC of 0.817 and accuracy of 0.748. DeLong test showed no significant differences among individual predictors (P>0.05), but the combined model significantly outperformed any single factor (P<0.05).

The personalized nomogram established based on the quantitative and qualitative characteristics of enhanced CT can non-invasively assist in the diagnosis of EBV status in patients with gastric cancer and can be used as a supplementary tool for pathological detection.