The Korean Journal of Gastroenterology  2012;59(5):347-353

doi:10.4166/kjg.2012.59.5.347

Usefulness of 18F-fluoro-2-deoxyglucose Positron Emission Tomography in Evaluation of Gastric Cancer Stage.

Na Ri YOON 1 ; Jae Myung PARK ; Hee Sun JUNG ; Yu Kyung CHO ; In Seok LEE ; Myung Gyu CHOI ; In Sik CHUNG ; Kyo Young SONG ; Cho Hyun PARK

Affiliations

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Keywords

Stomach neoplasms; Fluorodeoxyglucose F18; Positron-emission tomography; Lymph nodes; Neoplasm metastasis

Country

Republic of Korea

Language

Korean

Abstract

BACKGROUND/AIMS: The usefulness of 18F-fluoro-2-deoxyglucose (FDG)-PET in detecting primary cancer, lymph node metastasis, and distant metastasis were studied in the gastric cancer patients. METHODS: The subjects were 392 gastric cancer patients who received FDG-PET and an abdominal CT test prior to surgery. The results of FDG-PET and CT were compared with the surgical and pathologic results. RESULTS: The primary site detection rate of FDG-PET was 74.4%, 50.3% in early gastric cancer and 92.0% in advanced gastric cancer. Detection rate was higher when tumors were larger than 3.5 cm, had deeper depth of invasion, and at a later stage (p<0.05, respectively). In multivariate analysis, tumor size, spread of tumor cells beyond the muscle layer (> or =T2), and lymph node metastasis were statistically significant factors in primary site detection rate. The sensitivity, specificity, and positive predictive value of FDG-PET to lymph node metastasis were 59.6%, 88.8%, and 81.1% respectively, sensitivity being lower compared to CT while specificity and positive predictive value were higher. Sensitivity, specificity, and positive predictive value to distant metastasis were, respectively, 66.7%, 99.2%, and 88.0%, similar to CT. In 21 of the 392 patients (5.4%), synchronous double primary cancers were detected. CONCLUSIONS: In gastric cancer, usefullness of FDG-PET is limited to the advanced stage. Diagnostic value of this test was not superior to CT. However, FDG-PET may be useful in detecting synchronous double primary cancers.