Effects of radioiodine therapy on fertility indicators among men with differentiated thyroid cancer: A cohort study

Background: Following thyroidectomy, radioiodine therapy is the standard management of differentiated thyroid cancer. The effects of such treatment on testicular function remained a concern for cases and clinicians. Objective: We aimed to observe changes in fertility indicators in men treated with ablation. Materials and Methods: In this prospective cohort study, ۱۸ men with differentiated thyroid cancer from June to December ۲۰۲۰ underwent thyroidectomy plus radioiodine therapy. Participants were grouped based on iodine dose (۸ men with ۳۰ mCi vs. ۱۰ men with ≥ ۱۵۰ mCi). Baseline values (VB) of the follicular stimulating hormone, luteinizing hormone, testosterone, and sperm analyses were measured ۳ wk before iodine ablation and repeated ۳ (V۳) and ۱۲ (V۱۲) months later. They were analyzed once as a whole and once based on their groups via ANOVA and Friedman's tests where appropriate. Results: The mean age of participants was ۳۵.۶۱ ± ۹.۷۴ yr. Follicular stimulating hormone levels showed a significant trend among all participants (VB: ۱۲.۵۱ ± ۱.۷۲, V۳: ۱۳.۵۴ ± ۱.۴۱, and V۱۲: ۱۳.۱۰ ± ۱.۶۷ IU/mL; p < ۰.۰۰۱). Luteinizing hormone showed a similar pattern (VB: ۴.۹۸ ± ۱.۲۷, V۳: ۵.۶۵ ± ۱.۲۹, and V۱۲: ۵.۲۱ ± ۰.۹۵ IU/mL; p < ۰.۰۰۱). Testosterone levels did not differ significantly from baseline. Sperm count decreased at the first checkpoint and returned to normal after ۱۲ months (VB: ۳۸.۲۲ ± ۱۹.۴۰, V۳: ۳۲.۰۵ ± ۱۷.۹۶, and V۱۲: ۳۶.۶۶ ± ۱۸.۸۱ million/mL; p < ۰.۰۰۱). Sperm motility and morphology did not change significantly. Conclusion: Our research showed that even less than ۵ GBq irradiation could induce a transient testicular dysfunction in the first ۳ months of therapy, but it was mostly reversible after ۱۲ months.

Keywords:

Follicle-stimulating hormone , Iodine-۱۳۱ , Male infertility , Semen analyses. , هورمون محرک رشد , ید-۱۳۱ , ناباروری مردانه , آنالیز اسپرم.