SUMMARY OF THE STUDY
A total of 16 patients with thyroid cancer undergoing their first radioactive iodine therapy were enrolled in the study. They were divided into two groups: 8 patients in the selenium group received selenium for 10 days, 3 days before and 6 days after radioactive iodine therapy, the other 8 patients in control group received a placebo. Patients were treated with 100-150 mCi of radioactive iodine. The authors measured amylase, a protein produced by salivary glands before, 2 days and 6 months after radioactive iodine therapy. Also salivary gland scintigraphy, a study measuring salivary gland ability to produce saliva, was done before and 6 months after radioactive iodine therapy. A questionnaire evaluating symptoms of salivary gland dysfunction were given before and 6 months after radioactive iodine therapy.
Results of the study showed significantly higher increase of serum amylase 2 days after radioactive iodine therapy in control group compared to selenium group that reflects more injury to salivary glands in the placebo group. Moreover, the results of salivary scintigraphy and scores on the questionnaire 6 months after radioactive iodine therapy were significantly different in the selenium and placebo groups reflecting that the long term damage of salivary glands was higher in control group.
WHAT ARE THE IMPLICATIONS OF THIS STUDY?
This study suggests that selenium supplementation during radioactive iodine therapy may be protective to salivary glands. Studies with larger number of patients are needed to further evaluate the clinical significance of changes in laboratory work up and imaging studies.
— Valentina Tarasova, MD