OBJECTIVE: This study was conducted to explore the predictive value of PET parameters derived from METHODS: 72 GC patients who underwent RESULTS: Univariate analysis indicated a significant association between LVI/PNI status and PET parameters (SUVmax, SUVmean, and TBR) (all p <
0.002). The area under the ROC curve (AUC) values for predicting LVI/PNI were 0.932 [95% CI (0.877-0.987)] for SUVmax, 0.923 [95% CI (0.861-0.984)] for SUVmean, and 0.925 [95% CI (0.865-0.985)] for TBR. The optimal cutoff values for prediction, along with their corresponding sensitivity and specificity, were 3.86 (93.3% and 81.5%) for SUVmax, 2.04 (93.3% and 81.5%) for SUVmean, and 9.75 (91.1% and 81.5%) for TBR. Multivariate analysis identified histological grade and SUVmax as independent risk factors for LVI/PNI prediction. Our nomogram had good discriminatory ability (AUC = 0.934) and offered net benefits in predicting LVI/PNI status by DCA. CONCLUSION: This study demonstrates that FAPI uptake parameters exhibit an exceptionally high capacity and serve as a noninvasive preoperative tool for predicting LVI/PNI status in GC, with SUVmax emerging as the most suitable predictive indicator.