The effect of radioactive iodine treatment for differentiated thyroid cancer on male gonadal function: a meta-analysis

PURPOSE: The aim was to investigate the effect of radioactive iodine (RAI) treatment for differentiated thyroid cancer (DTC) on male gonadal function. METHODS: PubMed, Embase, Web of Science, OVID, Scopus, and Wanfang databases were searched up to June 10, 2022, to identify published studies related to RAI and male gonadal function. ReviewManager version 5.4.1 software was used to calculate mean differences (MDs) with 95% CIs. RESULTS: Initially, 1958 articles were retrieved from the databases, and 6 articles were included in the quantitative analysis. The meta-analysis results showed that follicle-stimulating hormone (FSH) increased when the follow-up duration was ≥12 months after RAI, but the difference was not statistically significant (MD = −2.64, 95% CI = (−5.61, 0.33), P = 0.08). But the results of the subgroup analysis showed that when the follow-up time was ≤6 months, FSH levels were significantly higher after RAI (MD = −7.65, 95% CI = (−13.95, −1.34), P = 0.02). The level of inhibin B was significantly lower at ≥12 months and ≤6 months after RAI (MD = 66.38, 95% CI = (8.39, 124.37), P = 0.02) and (MD = 116.27, 95% CI = (43.56, 188.98), P = 0.002). Additionally, luteinizing hormone (LH) and testosterone have similar results – that is, LH and testosterone levels were higher after RAI, but the difference was not statistically significant (MD = –0.87, 95% CI = (−2.04, 0.30), P = 0.15) and (MD = −1.69, 95% CI (−7.29, 3.90), P = 0.55). CONCLUSIONS: Male gonadal function may be temporarily impaired within 6 months after RAI but may return to normal levels afterward.