Purpose: We evaluated the value of fluorine-18 fluorodeoxyglucose positron-emission tomography/computed tomography (FDG PET/CT) as a complementary imaging modality to endoscopy to predict the curability of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC).
Methods: The institutional review board approved this retrospective study with a waiver of informed consent. The records of patients who underwent FDG PET/CT for initial routine staging of gastric cancer from January 2012 to October 2017 were reviewed retrospectively. Among them, the patients who had EGC with well or moderately differentiated adenocarcinoma were included in this study. A total of 210 EGCs in 199 patients (mean age ± SD, 67 ± 10 years) were selected for this study. For the analysis of FDG PET/CT image, the radiotracer uptake by the primary tumor was compared with the background gastric uptake. Each case was classified as curable by ESD (no discrete radioactivity) and not curable by ESD (discrete radioactivity).
Results: The detection rate of EGC by FDG PET/CT was 37.1% (78 discrete radioactivity in 210 EGCs). However, for the detection of EGC that is not curable by ESD, the sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve with 95% confidence intervals were 79% (67-87%), 91% (85-95%), 81% (71-88%), 89% (84-93%), and 0.85 (0.79-0.89), respectively.
Conclusion: FDG PET/CT may be a useful complementary imaging modality to endoscopy to predict the curability of ESD for EGC.
Keywords: Early gastric cancer; Endoscopic resection; Endoscopic submucosal dissection; FDG PET/CT.