Prophylaxis of esophageal ulceration was studied in 78 esophageal carcinoma patients after high-dose-rate intraluminal brachytherapy. Before the standard treatment regimen of radiotherapy was established, 15/17 patients developed ulcers. This decreased to 19/38 with the standard treatment regimen, and to 9/23 when antiulcer therapy was added (p < 0.01).