Clinicopathologic parameters associated with the FDG-avidity in staging of early gastric cancer using (18)F-FDG PET

This study investigated the clinicopathologic factors associated with 2-[(18)F]fluoro-2-deoxy-d-glucose ((18)F-FDG) uptake of early gastric cancer (EGC) and used them to design a clinical scoring method to predict FDG-avidity of EGC. Two hundred twenty-nine retrospectively enrolled patients underwent preoperative (18)F-FDG positron emission tomography/computed tomography (PET/CT). Histologic information was obtained by gastrectomy (n = 195) or endoscopic mucosal dissection (n = 34). The association between clinicopathologic factors and (18)F-FDG uptake by the primary tumor was determined. The results were used to develop a clinical scoring method. (18)F-FDG uptake was detected in 49 (17.5%) patients. According to univariate analysis, location, gross type, World Health Organization classification, Lauren classification, size, depth of invasion, and lymphatic invasion were significant variables affecting (18)F-FDG uptake (all P < .05). According to multivariate analysis, location (lower 3rd, P = .035), gross type (0–I, 0–IIa, P < .001), size (≥2.5 cm, P = .026), and depth of invasion (submucosa, P = .007) were significantly associated with FDG-avidity. A clinical scoring system, ranged from 0 to 4, was developed by giving one score to 4 independent variables. A cut-off value of 2.5 showed good prediction of FDG-avidity in EGCs, with a sensitivity and specificity of 65.0% and 85.2%, respectively. (18)F-FDG uptake by EGC depends on location, gross type, size, and depth of invasion of the primary tumor. A clinical scoring system based on clinicopathologic variables can predict the FDG-avidity of primary tumors in patients with EGC.