The Role of Gastric Distention in Differentiating Recurrent Tumor from Physiologic Uptake in the Remnant Stomach on 18F-FDG PET

Journal of Nuclear Medicine

Jong Doo Lee¹  Jung Kyun Bong¹  Mijin Yun¹  Young Hoon Ryu¹  Eunhye Yoo¹  Hyun Seok Choi¹ 

[1] Division of Nuclear Medicine, Department of Diagnostic Radiology, Yonsei University College of Medicine, Seoul, South Korea Division of Nuclear Medicine, Department of Diagnostic Radiology, Yonsei University College of Medicine, Seoul, South Korea Division of Nuclear Medicine, Department of Diagnostic Radiology, Yonsei University College of Medicine, Seoul, South Korea

关键词: gastroenterology;    oncology;    PET;   

DOI  :  

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

Physiologic 18F-FDG uptake in the stomach can often cause false-positive results and lowers the usefulness of 18F-FDG PET in evaluating the remnant stomach. We assessed the role of gastric distension to see whether it is beneficial for the differentiation of recurrent tumors from physiologic 18F-FDG uptake in the remnant stomach. Methods: Thirty patients (22 men and 8 women; age range, 27–80 y; mean age, 58.3 y) with a history of subtotal gastrectomy for gastric cancer underwent 18F-FDG PET for various clinical indications. After whole-body imaging, the patients were asked to drink water, and then spot imaging of the stomach was performed. 18F-FDG uptake in the remnant stomach was considered positive for malignancy if it was persistently increased, whether focal or diffuse, after water ingestion. We used 2 standardized uptake value (SUV) criteria to differentiate benign from malignant uptake. First, a lesion was considered benign if its SUV was less than 2 on whole-body imaging. Second, for a lesion with an SUV of 2 or above, it was classified as benign if SUV decreased by more than 10% after water ingestion. Results: Visual analysis of whole-body images produced 9 true-negative, 4 false-positive, 16 true-positive, and 1 false-negative results. Use of additional spot images produced 12 true-negative, 1 false-positive, 15 true-positive, and 2 false-negative results. When an SUV cutoff of 2 was applied for malignancy before water ingestion, all 17 patients with local recurrence were correctly identified, but 11 of the 13 patients without local recurrence were falsely considered to have a recurrent tumor in the remnant stomach. To reduce the false-positive results, we used the second SUV criterion after water ingestion. Use of that criterion produced 4 false-negative results although it correctly identified the 11 false-positive results as true negative. Conclusion: Gastric distension by having patients drink a glass of water seems to be a simple, cost-effective way of improving the diagnostic accuracy of 18F-FDG PET in patients with suspected recurrence in the remnant stomach. Visual analysis with special attention to the configuration of 18F-FDG activity after water ingestion seems to be more useful than the change in SUV in evaluating the remnant stomach.

【 授权许可】

Unknown