Abstract:Objective To describe the endoscopic observation of pancreatic cancer radiotherapy induced gastroduodenal radioactive injury, and investigate the influence of radiation-induced ulceration by concurrent chemoradiotherapy with S-1 (Tegafur Gimeracil Oteracil Potassium Capsule) and gemcitabine. Methods Self-comparative study of endoscopic performance were performed on patients received endoscopy before and after pancreatic cancer Chemoradiotherapy with S-1 or gemcitabine or radiotherapy only, from February 2010 to May 2015. Pearson chi-square test was used to analyze whether Concurrent Chemoradiotherapy groups and radiotherapy group are different in radiation-induced ulceration occurrence rate. Results The incidence of radiation-induced ulceration of radiotherapy group, S-1 group and gemcitabine group are 44.1 % (26/59), 50.0 % (10/20) and 46.7 % (7/15), respectively. Radiation-induced ulceration incidence was no statistical difference among the three groups. Conclusion From the angle of safety, patients can according to their self-condition for choosing S-1 or gemcitabine chemotherapy. Wether the concurrent chemoradiotherapy treatment was adopted or not, the occurrence rate of radiation-induced ulceration has no significant difference.