Abstract:Objective: To assess the clinical application value of 18F-FDG PET/CT on TNM staging of gastric cancer. Methods: PET/CT scan were performed in 33 newly diagnosed gastric carcinoma patients within two weeks before operation. Primary lesions, lymph nodes metastasis and distant metastasis of all patients were diagnosed by pathological examination, other imaging findings and clinical follow up for more than 6 months. The value of PET/CT in the diagnosis and staging of gastric cancer was assessed by comparing the findings of PET/CT with the clinical findings. Results: Compared with operative pathology in 33 patients, the sensitivity of 18F-FDG PET and PET/CT for diagnosing primary lesions of gastric cancer were 84.8%and 100%. In 33 patients, the diagnostic concordance of PET/CT with pathological and clinical findings for T-stage, N-stage, M-stage and TNM-stage were 81.8%, 75.8%, 93.9% and 90.9%, respectively(Kappa value was 0.514, 0.557, 0.767 and 0.759 respectively, P<0.01). Conclusions: 18F-FDG PET/CT plays an important role in the diagnosis and TNM staging for gastric cancer with a good concordance of TNM staging with operative pathology. False-negative commonly occurs in patients with signet-ring cell carcinoma and especial attention should be paid on them.