Ablation success and long-term recurrence with low-dose versus high-dose radioiodine for remnant thyroid ablation in differentiated thyroid carcinoma: A systematic review and meta-analysis of randomized controlled trials.

Abstract

e18119 Background: Differentiated thyroid carcinoma (DTC) is the most common endocrine malignancy. It is typically managed with thyroidectomy followed by remnant ablation using radio-iodine (RAI) therapy which reduces recurrence risk and facilitates follow up. Although high-dose RAI (100-150 mCi) has been the standard treatment, low-dose regimens (30-50 mCi) may reduce radiation exposure and toxicity, but their comparative efficacy in achieving ablation success and preventing recurrence remains uncertain. We performed a systematic review and meta-analysis of randomized controlled trials comparing low-dose versus high-dose radio-iodine for remnant thyroid ablation. Methods: A comprehensive search of PubMed, Cochrane library,and clinicaltrials.gov was conducted from inception until September, 2025.Data on ablation outcomes and long-term recurrence rate was extracted. Data was analyzed on R studio version 4.1.1, forest plots were generated using random effect model, and heterogeneity was assessed using I² statistics. Results: Sixteen randomized control trials including 4,047 patients (n=2,098 low dose; n=1,949 high dose) were analyzed. Initial ablation success was reported in 14 trials (n=3,385) and indicated that high-dose radio-iodine significantly improved initial ablation success compared to low-dose (RR: 0.93, 95% CI 0.89–0.98; P = 0.0083; I² = 40%). Long-term recurrence was reported in 8 studies including 2,983 participants. There was no statistically significant difference between low- and high-dose radioiodine (RR 0.94, 95% CI 0.63–1.42; P = 0.78), with high consistency across trials (I² = 0%). Conclusions: This meta-analysis demonstrates that high-dose radio-iodine statistically improves initial ablation success compared to low-dose in patients with differentiated thyroid carcinoma; however, long-term recurrence rates are similar between doses. These findings highlight that careful patient selection and further studies with standardized follow up are warranted to optimize dosing strategy.