P-135 Endoscopic Changes and Long-term Outcome of Radiotherapy for Helicobacter pylori Negative/Refractory Gastric Marginal Zone B Cell Lymphoma

Abstract

Introduction: Low-grade gastric marginal zone B cell lymphoma (MALToma) usually responds to eradication of H. pylori but when it is ineffective, radiotherapy is one of the most effective second line treatment modalities. However, the endoscopic changes of gastric mucosa after radiotherapy and the long-term outcome of radiotherapy for gastric MALToma have not been established. The aims of this study were to evaluate the effect of radiotherapy on gastric mucosa and the long-term efficacy of radiotherapy for gastric MALToma. Methods: Patients who underwent radiotherapy for gastric MALToma and who were followed up for more than two years were retrospectively investigated. We reviewed the endoscopic findings of gastric mucosa before and after radiotherapy. Efficacy of radiotherapy and its adverse events were also analyzed. Results: Six patients were included in this study (3 patients refractory to successful H. pylori eradication; 3 patients who were H. pylori negative initially) and median follow up duration was 50.5 months. Erythematous gastritis developed in one patients and flat erosive gastritis developed in one patients immediately after radiotherapy. Long-term follow up endoscopy did not show any additional mucosal changes in all the patients. Radiation was well tolerated and all six patients achieved complete remission. No severe late adverse events developed and the overall and disease free survival rate were 100% each. Conclusion: Radiotherapy for patients with gastric MALToma was effective without any critical acute or late adverse events.