Postoperative radioiodine (RAI) versus no radiodine therapy for patients with low-risk differentiated thyroid cancer: A systematic review and meta-analysis.

Abstract

e18157 Background: Postoperative radioiodine (RAI) treatment is commonly used for remnant ablation as a standard adjuvant therapy for patients with differentiated thyroid cancer (DTC) . However, the clinical efficacy of RAI therapy in low-risk patients remains controversial. This systematic review and meta-analysis aims to evaluate the effectiveness of postoperative RAI in low-risk DTC patients in reducing disease recurrence. Methods: PubMed, Embase, and Cochrane Central databases were searched for randomized controlled trials and observational studies comparing patients with low-risk DTC who underwent thyroidectomy or lobectomy, and were treated with either RAI ablation or a placebo. We evaluated structural response, recurrence rate, and recurrence-free survival. We computed risk ratio (RR) for binary endpoints, with 95% confidence intervals (CI). All statistical analyses were performed using R (version 4.4.1). Results: A total of seven studies were analyzed, comprising 5,480 patients with low-risk DTC who underwent thyroidectomy, of whom 3,695 (67.4%) administered RAI. The incidence of structural recurrences was lower in the RAI group, but the analysis showed no statistical difference between the treatment strategies (1.4% vs 2.6%; RR 0.53; 95% CI 0.26 - 1.09; p=0.09; I²=30%). Compared with the nonuse of RAI, there was no significant increase in the recurrence rate (RR 0.80; 95% CI 0.35 - 1.82; p=0.60; I²=56%). The recurrence-free survival outcome was comparable between RAI ablation and no RAI after surgery (RR 1.00; 95% CI 0.96 - 1.04; p=0.98; I²=86%). Conclusions: This meta-analysis found no statistically significant difference in recurrence rate, recurrence-free survival, or structural response between radioiodine ablation and placebo in patients with low-risk DTC who had undergone thyroidectomy or lobectomy. These findings highlight the need for individualized treatment approaches and further research to refine the role of in this population. Study Structural Recurrence[RR (95% CI)] Recurrence Rate[RR (95% CI)] Recurrence Free Survival[RR (95% CI)] Biglic 2024 0.25 (0.03, 2.21) 0.13 (0.02, 0.99) - Leboulleux 2022 0.67 (0.11, 4.01) 0.95 (0.48, 1.89) 1.00 (0.97, 1.03) Lee 2024 - 3.99 (0.49, 32.25) - Satapathy 2023 0.60 (0.32, 1.13) 0.38 (0.14, 1.07) 1.01 (1.00, 1.02) Schvartz 2012 3.40 (0.43, 27.08) - 0.95 (0.92, 0.99) Veronica Ilera 2023 - - - Xu 2024 0.23 (0.07, 0.75) - 1.03 (0.96, 1.04) Total (95% CI) 0.53 (0.26, 1.09) 0.80 (0.35, 1.82) 1.00 (0.96, 1.04) p-value 0.09 0.60 0.98