Radio-iodine therapy and Helicobacter pylori infection.
BACKGROUND
Helicobacter pylori is the most important cause of gastritis and related morbidities. Following consumption, radioactive iodine accumulates considerably in the stomach. On the basis of this observation, we decided to determine whether the high radiation induced by radio-iodine in the stomach is effective in the eradication of this infection.


METHODS
All consecutive patients with differentiated thyroid carcinoma, who were referred for radio-iodine therapy [dose 117.1 +/- 24.4 mCi (4.3 +/- 0.9 GBq), range 100-200 mCi (3.7-7.4 GBq)], were enrolled. To detect H. pylori infection, the urease breath test (UBT) was performed 1-2 h before radio-iodine consumption and the test was repeated 2 months later.


RESULTS
Of 88 patients, 71 had pre-treatment positive UBT. Of these, 23 patients had negative post-treatment result, which means a significant reduction (26.1%, 95% CI 16.8-35.5%) in the number of positive UBT results in our treated population (32.4% of UBT-positive cases became UBT-negative).


CONCLUSIONS
Considering the high prevalence of reinfection in developing countries, the therapeutic benefit would have been more considerable if the second UBT had been done with a lag time of less than 2 months. Although radio-iodine therapy is not a logical method for the treatment of patients suffering from H. pylori, our finding provides indirect evidence about the radiosensitivity of bacteria, the future clinical applications of which need to be further evaluated. Also this finding can be useful for the food industry, where radiation is used widely to sterilize food. Regarding the possibility of H. pylori suppression, we recommend not using UBT for screening for the infection for at least within 2 months following radio-iodine therapy.
Gholamrezanezhad
Ali
A
Research Institute for Nuclear Medicine, Medical Sciences/University of Tehran, Shariati Hospital, North Karegar St., 14114 Tehran, Iran. gholamrezanejhad@razi.tums.ac.ir
Mirpour
Sahar
S
Saghari
Mohsen
M
Abdollahzadeh
Javaher
J
Pourmoslemi
Aydin
A
Yarmand
Sarah
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000532:radiotherapy*; D016480:Helicobacter pylori / Q000528:radiation effects*; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D016896:Treatment Outcome; D055815:Young Adult
D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals