Roque C, Santos FS, Pilli T, et al. - As there is a lack of long-term studies examining toxic multinodular goiter (TMNG) treatment with fixed activities of radioiodine (RAI), researchers sought to explain the long-term effects of 15 mCi on thyroid volume, function, and autoimmunity. A population-based, retrospective analysis with up to 12 years of follow-up was carried out in Siena, Italy. Participants in the study were 153 adult patients with TMNG, naive to RAI. Hyperthyroid patients decreased nearly by 50% per year without additional RAI during the first 3 years after treatment. Except for antithyrotropin receptor antibodies and hyperthyroidism, there was no statistically significant association of the antibody titers with thyroid function. It was noted that 89% of hyperthyroidism was treated. Treatment of TMNG with 15 mCi of RAI caused low rates of hypothyroidism while providing high cure rates and significant reduction in volume, sustained over the long term.