Evaluation of 18F‐2‐deoxy‐2‐fluoro‐d‐glucose Positron Emission Tomography for Gastric Cancer

Abstract

Positron emission tomography (PET) with 18 F‐2‐deoxy‐2‐fluoro‐d‐glucose (FDG) has been investigated as a means of detecting certain primary tumors and their metastatic disease in recent years. The aim of this study was to compare the performance of FDG‐PET and operative assessment with formal pathologic staging. Altogether, 85 patients had undergone surgical treatment for gastric cancer with curative intent, with FDG‐PET preoperatively. The results using FDG‐PET were compared with those using computed tomography (CT); they were also correlated with the pathologic findings. For quantitative analysis, the regional tumor uptake was measured by the standard uptake value (SUV) using a region of interest technique. Using FDG‐PET, the primary tumor was visualized in 75.2% of patients. A comparison of the FDG uptake and the clinicopathologic findings showed that there was a significant association between FDG uptake and the depth of invasion, the size of the tumor, and lymph node metastasis. FDG‐PET scans had less accuracy for diagnosing locoregional lymph nodes than CT because of a significant lack of sensitivity (23.3% vs. 65.0%). The survival rate for patients with high FDG uptake (SUV > 4) was significantly lower than that for those with low FDG uptake (SUV < 4) (p < 0.05). FDG‐PET was successful in detecting the primary gastric cancer lesion but not for finding early‐stage gastric cancers. Detection of nodal metastasis also was not possible by FDG‐PET. However, FDG‐PET appears to provide important additional information concerning the aggressiveness of the tumor and the prognosis in patients with gastric cancer.