Utility of 68GaFAPI-04 and 18FFDG dual-tracer PET/CT in the initial evaluation of gastric cancer

Abstract Objectives We aimed to investigate the role of 68 GaFAPI-04 and 18 FFDG dual-tracer PET/CT for the initial assessment of gastric cancer and to explore the factors associated with their uptake. Methods This study enrolled 62 patients with histopathologically confirmed gastric cancer. We compared the diagnostic performance of 68 GaFAPI-04, 18 FFDG, and combined dual-tracer PET/CT. The standardized uptake value (SUV) and tumor-to-background ratio (TBR) were also measured, and the factors that influence tracer uptake were analyzed. Results 68 GaFAPI-04 PET/CT detected more primary lesions (90.3% vs 77.4%, p = 0.008) and peritoneal metastases (91.7% vs 41.7%, p = 0.031) and demonstrated higher SUV max and TBR values ( p 0.05). Conclusions In this initial study, 68 GaFAPI-04 and 18 FFDG dual-tracer PET/CT were complementary and improved sensitivity for the detection of distant metastases pre-treatment in gastric cancer and could improve treatment stratification in the future. 68 GaFAPI-04 had limited efficacy in detecting EGC. Key Points • 68 GaFAPI-04 and 18 FFDG dual-tracer PET/CT are complementary to each other for improving diagnostic sensitivity in the initial evaluation of distant metastases from gastric cancer. • 68 GaFAPI-04 PET/CT showed limited sensitivity in detecting EGC. • Need for further validation in a larger multi-centre prospective study.