18F-FDG PET/CT Role in Staging of Gastric Carcinomas: Comparison with Conventional Contrast Enhancement Computed Tomography

The purpose of the report was to evaluate the role of fluorine-18 fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (F-18-FDG PET/CT) in staging gastric cancer comparing it with contrast enhancement computed tomography (CECT). This retrospective study included 45 patients who underwent performed whole body CECT and F-18-FDG PET/CT before any treatment. We calculated CECT and F-18-FDG PET/CT sensitivity, specificity, accuracy, positive and negative predictive values (PPV and NPV) for gastric, lymphnode, and distant localizations; furthermore, we compared the 2 techniques by McNemar test. The role of F-18-FDG PET/CT semiquantitative parameters in relation to histotype, grading, and site of gastric lesions were evaluated by ANOVA test. Sensitivity, specificity, accuracy, PPV and NPV of CECT, and F-18-FDG PET/CT for gastric lesion were, respectively, 92.11%, 57.14%, 86.66%, 92.11%, 57.14% and 81.58%, 85.71%, 82.22%, 96.88%, 46.15%. No differences were identified between the 2 techniques about sensitivity and specificity. No statistical differences were observed between PET parameters and histotype, grading, and site of gastric lesion. The results of CECT and F-18-FDG PET/CT about lymphnode involvement were 70.83%, 61.90%, 66.66%, 68%, 65% and 58.33%, 95.24%, 75.55%, 93.33%, 66.67%. The results of CECT and F-18-FDG PET/CT about distant metastases were 80%, 62.86%, 66.66%, 38.10%, 91.67% and 60%, 88.57%, 82.22%, 60%, 88.57%. (18)FDG PET/CT specificity was significantly higher both for lymphnode and distant metastases. The F-18-FDG PET/CT is a useful tool for the evaluation of gastric carcinoma to detect primary lesion, lymphnode, and distant metastases using 1 single image whole-body technique. Integration of CECT with F-18-FDG PET/CT permits a more valid staging in these patients.