Selection of dilution material for non-iodinated iodine as an oral contrast agent for esophageal cancer: a preliminary clinical trial

PURPOSE: To investigate the filling state of the esophagus using different oral contrast agents for the diagnosis of esophageal cancer by computed tomography (CT). MATERIALS AND METHODS: This preliminary clinical trial enrolled patients with suspected esophageal carcinoma and admitted from January 2015 to January 2018. The patients were randomized into the yogurt (mixed with ioversol), lotus root powder (mixed with ioversol), gas-producing powder, and control (pure iodine water) groups. Chest CT examinations were performed. The degree of esophageal filling and the detection of esophageal lesions were compared. RESULTS: Finally, 136 participants were enrolled (n = 34/group). There were no significant differences in esophageal filling degree among the yogurt, lotus root powder, and gas-producing powder groups (P = 0.093). There were 30/3/1 and 30/3/1 confirmed/false-negative/false-positive diagnoses in the yogurt and lotus powder groups, respectively, compared with 28/5/1 and 25/8/1 in the gas-producing powder and control groups, respectively. The concordance rates were the highest for the yogurt (88.2%, with 91.7% specificity and 86.4% sensitivity) and lotus root powder groups (88.2%, with 92.3% specificity and 85.7% sensitivity) and the lowest for the control group (73.5%, with 90.0% specificity and 66.7% sensitivity). CONCLUSION: Yogurt mixed with ioversol could fill and expand the esophagus with minimal preparation, displaying the structure of the esophageal lumen and wall thickness. This mixture might be used as a positive contrast agent for esophageal CT. Similar results were observed for the lotus root powder mixed with ioversol, but its preparation was more arduous.