What is the effect of radioiodine therapy on Helicobacter pylori infection?

Background/aim: Helicobacter pylori is an important human pathogen associated with gastric and duodenal ulcers, gastric mucosaassociated lymphoid tissue lymphoma, and adenocarcinoma. Radioiodine (RAI) treatment plays an important role in the management of differentiated thyroid cancer and primary hyperthyroidism. It is known that during RAI treatment, a considerable amount is absorbed by the stomach as well. In this study we aimed to reveal any therapeutic impact of RAI on H. pylori infections. Materials and methods: Eighty-seven patients who were hospitalized for RAI treatment were consecutively included in this study. Of those, 76 patients had differentiated thyroid cancer and 11 had primary hyperthyroidism. The urea breath test (UBT) was performed on the day before RAI, and the test was repeated after 2 months. Results: The dose of RAI was 115 ± 3.3 mCi (range: 100–150 mCi) in the patients with malignant disease and 22.7 ± 1.4 mCi (range: 20–30 mCi) in the remaining patients. Among the patients with differentiated thyroid cancer, 44 (57%) had positive and 32 (43%) had negative UBT tests prior to RAI. Four (36%) patients with hyperthyroidism had pretreatment positive UBT tests and 7 (64%) had negative tests. The results of UBT conducted 2 months after RAI therapy were identical in every patient, which means that none of the patients with positive UBT became UBT-negative (P = 1). Conclusion: RAI does not have any therapeutic effect on H. pylori infection.