Reply: Egg Labeling for Gastric-Emptying Studies

REPLY: We appreciate the comments by Drs. Currie and Wheat on our study that evaluated different methods to prepare an egg-based radiolabeled meal for gastric-emptying scintigraphy (1). The message of our study was that labeling methods and cooking methods need to be evaluated for any solid meal before one can adopt it for performing a gastric-emptying study. We also demonstrated in our paper that in vitro evaluation of stability in “simulated gastric conditions” may give different results if the incubation solution is dilute hydrochloric acid rather than human gastric fluid, which would contain pepsin in addition to acid. In attempting to directly answer Drs. Currie and Wheat, we find that the data mentioned in their letter are brief and omit adequate details on how their foods were combined with radiotracers and how cooking, digestion, and quantification were performed. Our studies support using a low-fat egg-substitute meal (EggBeaters; ConAgra Foods, Inc.), which is the meal suggested by a consensus working group of the Society of Nuclear Medicine and the American Neurogastroenterology and Motility Society (2). We agree on the importance of developing alternative meals and would urge the researchers at Charles Sturt University to proceed with full publication of the details of their studies.