Effect of recombinant human thyroid-stimulating hormone or levothyroxine withdrawal on salivary gland dysfunction after radioactive iodine administration for thyroid remnant ablation

Background. The purpose of this study was to examine the incidence of sialadenitis and xerostomia within a year after radioactive iodine administration for thyroid remnant ablation after preparation with recombinant human thyroid-stimulating hormone (rhTSH) or levothyroxine (LT4) withdrawal. Methods. The study has included 121 patients, divided into 4 groups: group A (rhTSH = 100 mCi), group B (rhTSH = 70 mCi), group C (LT4 withdrawal = 100 mCi), and group D (LT4 withdrawal = 70 mCi). Study outcomes were Summated Xerostomia Inventory score and number of sialadenitis episodes after radioactive iodine administration. Results. Salivary gland dysfunction was reported in 31% and 12% of patients, at the end of months 1 and 12, respectively. There was significantly lower incidence in groups A and B in comparison with groups C and D (p = .002 and .021, respectively). Conclusion. The use of rhTSH for preparation of radioactive iodine ablation as opposed to LT4 withdrawal reduces the incidence of salivary gland dysfunction. (C) 2015 Wiley Periodicals, Inc.