ABSTRACT
Objective:To explore the relationship between 18F-fibroblast activation protein inhibitor (FAPI)-42 SUV max of primary gastric cancer and clinicopathological factors of patients. Methods:Fifty-one patients (31males, 20 females, age: 51(47, 65) years) with gastric cancer who underwent 18F-FAPI-42 PET/CT before surgical resection in Nanfang Hospital, Southern Medical University from February 2022 to January 2023 were analyzed retrospectively. The clinicopathological factors that might affect tumor SUV max (including gender, age, tumor location, pathological type, histological grade, Lauren classification, vascular and(or) neural invasion, programmed cell death-ligand 1 (PD-L1) expression, pathologic(p)T stage, pN stage and pTNM stage) were evaluated by the univariate analysis (Mann-Whitney U test or Kruskal-Wallis rank sum test) and multivariate analysis (multiple linear regression analysis). Results:The sensitivity of 18F-FAPI-42 PET/CT in the diagnosis of patients with primary gastric cancer was 82.35% (42/51). The diagnostic sensitivities for early gastric cancer (T1) and locally advanced gastric cancer (T2-T4) were 59.09%(13/22) and 100%(29/29), respectively. The SUV max of primary lesion was 4.90(1.71, 12.51). The univariate analysis showed that SUV max of primary gastric cancer was related to tumor location ( z=-2.00, P=0.046), pT stage ( H=36.94, P<0.001), pN stage ( z=-3.89, P<0.001), pTNM stage ( H=31.49, P<0.001) and vascular and(or) nerve invasion ( z=-5.22, P<0.001), but not related to pathological type, histological grade, Lauren typing, and PD-L1 expression ( z values: from -1.78 to -0.09, all P>0.05). pT stage was found to be a significant independent factor for SUV max in primary gastric lesion by multivariate analysis ( t=2.52, P=0.015). Conclusions:The 18F-FAPI-42 SUV max of primary tumor was related to tumor location, pT stage, pN stage, pTNM stage, and vascular and(or) nerve invasion; pT stage is an independent factor affecting tumor SUV max. The ability of 18F-FAPI-42 PET/CT to detect gastric cancer is mainly affected by pT stage.