Abstract
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Objectives: To determine the optimal cutoff timepoint for rapid gastric emptying. This is one of the items suggested for further investigation in the 2008 published Consensus Recommendations for Gastric Emptying Scintigraphy 1.
Methods: In accordance with the National Standard Protocol (NSP), which is based on the consensus recommendations of the ANMS/SNMMI, patients were given a standard low-fat, egg-white meal radiolabeled with 1 mCi Tc99m Sulfur Colloid. Anterior and posterior planar gamma camera imaging was performed at 0, 0.5, 1, 1.5, 2, 2.5, and 4 hours as per combined NSP and established Miami Method (MIA). Quantitation was performed at each time point using geometric mean activity of decay-corrected counts expressed as percent emptying and/or percent retention. The data from 1002 patients was analyzed for abnormal versus normal gastric emptying (GE) with special attention in determining the optimal time point for rapid gastric emptying.
Results: In our large cohort of 1002 patients rapid GE was found in 81 patients at 0.5 h (<70% retention) and in 29 patients at 1 h (<30% retention) per NSP criteria. We hypothesized that if all of the patients with rapid GE at 0.5 h had normal gastric emptying at 4 h, then the study could be potentially be terminated at 30 minutes. Of these 81 patients, 79 had normal 4 h value of <10% retention, however there were two patients that had abnormal 4 h value of >10% retention. One of these patients was having post prandial vomiting and a large pancreatic cyst with inflammatory changes and subsequently was diagnosed with pancreatic cancer. The other had history of laparoscopic cholecystectomy and diabetes treated with Metformin.
Conclusions: Our analysis of 1002 patients is the largest single-study published cohort to date for assessment of GE. Based on our patient population and the combined MIA and NSP method more patients are identified as having rapid GE if the 0.5 h (<70% retention) time point is used as opposed to the currently recommended 1 h (<30% retention) time point. Further clinical correlation of these 81 patients found by 0.5 h GE to have rapid emptying is warranted. With a multidisciplinary approach we aim to assess each case for clinical concordance to validate that the 0.5 h is more sensitive in diagnosing rapid GE. 1 A Joint Report of the American Neurogastroenterology and Motility Society and the Society of Nuclear Medicine (Am J Gastroenterol 2008;103:753-763).