James DL, Ryan ÉJ, Davey MG, et al. - A systematic search of the databases PubMed, Cochrane Collaboration, Embase, Scopus, and Web of Science was conducted to assess the long-term cure rate of different radioactive iodine (RAI) activities in low- and intermediate-risk differentiated thyroid cancer (DTC). Successful remnant ablation, adverse effects, and hospital length of stay were among the secondary outcomes. Ten studies with a total of 3,821 patients met the inclusion criteria, including six randomized clinical trials and four observational studies. No difference was found between low-activity and high-activity RAI in terms of long-term cure recurrence rates or successful remnant ablation. Low-activity RAI was similar to high-activity RAI in terms of successful ablation and recurrence rates in this systematic review and meta-analysis. This suggests that in low- and intermediate-risk DTC, low-activity RAI is preferable to high-activity RAI due to comparable effectiveness but lower morbidity.