F18-fluorodeoxyglucose-positron emission tomography and computed tomography is not accurate in preoperative staging of gastric cancer

Purpose: To investigate the clinical benefits of F18-fluorodeoxyglucose-positron emission tomography and computed tomography (F-18-FDG-PET/CT) over multi-detector row CT (MDCT) in preoperative staging of gastric cancer. Methods: FDG-PET/CT and MDCT were performed on 78 patients with gastric cancer pathologically diagnosed by endoscopy. The accuracy of radiologic staging retrospectively was compared to pathologic result after curative resection. Results: Primary tumors were detected in 51 (65.4%) patients with F-18-FDG-PET/CT, and 47(60.3%) patients with MDCT. Regarding detection of lymph node metastasis, the sensitivity of FDG-PET/CT was 51.5% with an accuracy of 71.8%, whereas those of MDCT were 69.7% and 69.2%, respectively. The sensitivity of F-18-FDG-PET/CT for a primary tumor with signet ring cell carcinoma was lower than that of F-18-FDG-PET/CT for a primary tumor with non-signet ring cell carcinoma (35.3% vs. 73.8%, P < 0.01). Conclusion: Due to its low sensitivity, F-18-FDG-PET/CT alone shows no definite clinical benefit for prediction of lymph node metastasis in preoperative staging of gastric cancer.