Improving evaluation of primary gastric malignancies by distending the stomach with milk immediately before 18F-FDG PET scanning.

UNLABELLED This study was designed to investigate the feasibility and effectiveness of a modified protocol for (18)F-FDG PET that was proposed to improve the identification of primary gastric malignancies. METHODS In the modified protocol, patients were asked to drink 300-500 mL of cow milk to distend the stomach immediately before PET scans instead of fasting all along. For investigation of the influence of ingested milk on (18)F-FDG distributions, 43 nondiabetic patients without documented gastric diseases underwent both empty- and distended-stomach PET scans (79 and 72 scans, respectively) in their serial follow-up studies. For the evaluation of proven gastric malignancies, 24 patients who underwent distended-stomach PET scans were compared with 17 patients who underwent conventional empty-stomach examinations. RESULTS Ingestion of milk nearly 1 h after (18)F-FDG injection had no significant influence on distributions to the heart (P = 0.16), mediastinum (P = 0.50), and liver (P = 0.49), whereas the percentages of intense and moderate uptake in the stomach changed from 38.0% and 59.5% to 0% and 11.1%, respectively. With the normal gastric wall distended, malignant lesions were observed with higher contrast and clearer outlines, and some of them were detected at a small size (1.2 cm) at an early stage and with mild uptake. CONCLUSION Gastric distention with milk just before (18)F-FDG PET is a simple and effective method for improving the evaluation of primary gastric malignancies.