Radiolabeling of ensure, a food supplement, with ^99mTc and optimization of scintigraphy protocol for liquid gastric emptying time

Gastric emptying scintigraphy using radiolabeled solid meal (^99mTc sulfur colloid-IDLI) is considered as the best method to diagnose delayed gastric emptying. Radiolabeled liquid meal emptying studies have also been employed using ^99mTc/¹¹¹I-DTPA to diagnose gastric emptying although it is less sensitive but holds importance for patients who cannot tolerate solids. Hence, the present study aimed at radiolabeling the nutrient supplement solution (Ensure) as a tracer for studying the liquid emptying time in patients with dyspepsia and gastroparesis. The study aims to standardize the labeling procedure of ^99mTc-Ensure and perform it quality control and evaluate the final labeled product as a potential clinical product for liquid gastric emptying study. ^99mTc-Ensure can be labeled in-house with good labeling efficiency, and it demonstrates in vivo stability for up to 2 h with no free ^99mTc localization in the thyroid gland, salivary glands in any of the patients. Hence, ^99mTc-Ensure can be used as a potential liquid meal in gastric emptying studies