Abstract: Objective To analyze factors associated with failure to cure or recurrence of hyperthyroidism in patients with Graves disease (GD) after 131I treatment using ultrasound combined with Ki67 detection. Methods Eighty-nine patients with GD receiving 131I treatment in the Department of Nuclear Medicine at our hospital from January, 2020 to November, 2021 were enrolled. Before treatment, thyroid volume, shear wave elastic value and Ki67 expression in the follicular epithelial cells were measured using three-dimensional ultrasonic virtual organ computer-aided analysis, shear-wave elastic imaging and ultrasound-guided fine needle aspiration. The data including age, gender, antithyroid drug (ATD) history, dose of 131I, and TRAb were collected from all the cases. The patients were followed up for up to 1 year, starting at 1 month after 131I treatment, and the follow-up results of the patients were divided into failure to cure or recurrence of hyperthyroidism, premature hypothyroidism and euthyroidism or loss to follow- up. The proportional hazards model and fine-Gray test were used to estimate the adjusted hazard ratio (HR) and 95% confidence interval (95% CI) for patients with failure to cure or recurrence of hyperthyroidism. Results Among the 89 patients, 27 patients were found to have failure to cure or recurrence of hyperthyroidism, 50 had premature hypothyroidism, 1 patient had euthyroidism, and 11 patients were lost to follow-up at the end of the 1-year follow-up. Analysis of the competitive risk model showed that status of Ki67 expression, 131I dose and thyroid volume were independently correlated with failure to cure or recurrence of hyperthyroidism after the treatment with HR (95% CI) of 0.36 (0.15, 0.86), 0.81 (0.68, 0.96) and 1.11 (1.07, 1.15), respectively. Conclusion In patients with GD, the expression of Ki67 in thyroid follicular epithelial cells, 131I dose and thyroid volume are independently correlated with failure to cure or recurrence of hyperthyroidism after 131I treatment. New ultrasound techniques can play an important role in evaluating the therapeutic outcome of 131I treatment in GD patients.

Key words: Graves disease; ¹³¹I treatment; Ki67; competing risk model