Gastric ulcer localization by direct in vivo labeling of sucralfate. Work in progress.

We developed and evaluated a new procedure for imaging gastric ulcer disease with technetium 99m-labeled sucralfate. The new method employs direct in vivo labeling of sucralfate instead of in vitro labeling using human serum albumin, as previously reported in the literature. Tests using hydrochloric acid and a rabbit ulcer model showed the efficacy of the direct in vivo labeling technique and the ability of the tagged material to bind to ulcers, respectively. In 26 studies using humans with sucralfate labeled directly in vivo, 15 gave true-negative results and 11 gave true-positive results. Of 14 studies using humans with in vitro labeled sucralfate, three gave true-negative results, three gave true-positive results, and the results of eight were either false-negative or could not be interpreted because of high levels of activity remaining in the stomach. We suggest that the direct in vivo labeling method significantly improves the sucralfate gastric ulcer imaging technique.