Single-Session High-Intensity Focused Ultrasound Treatment for Persistent or Relapsed Graves Disease: Preliminary Experience in a Prospective Study.

Purpose To evaluate the safety and efficacy of ultrasonography (US)-guided high-intensity focused ultrasound (HIFU) ablation as a treatment for medically refractory Graves disease (GD). Materials and Methods After ethics approval, a prospective trial (NCT02685514) was performed from November 2015 to February 2016. Thirty patients underwent ablation of the entire right and left thyroid lobes, with areas near the tracheal-esophageal groove and common carotid artery left unablated. Serum thyroid-stimulating hormone (TSH), free T4 (FT4), antithyroid autoantibodies, and TSH receptor (TSHR) antibody levels were evaluated afterward, and US color Doppler, US volumetry, and eye assessment were performed. The primary outcome was the 12-month relapse rate. Relapse referred to hyperthyroidism (FT4 > 23 pmol/L) afterward. Variables associated with relapse were analyzed by using binary logistic regression. Results The technical success rate was 96.7%. The cohort comprised entirely women, with a median age of 38.2 years (interquartile range, 29.5-49.0 years). After 12 months, eight patients (26.7%; 95% confidence interval [CI]: 14.19%, 44.95%) experienced relapse. One patient (3.3%; 95% CI: 0.59%, 16.67%) experienced vocal cord palsy, while two patients (6.7%; 95% CI: 1.85%, 21.33%) experienced Horner syndrome, but none of these conditions were permanent. No changes in gland volume, antithyroid autoantibody levels, and ophthalmic parameters were found at 12-month follow-up. Baseline TSHR was found to have decreased significantly at 6- and 12-month follow-up (P < .001 for both). TSHR antibody (odds ratio [OR] = 1.414; 95% CI: 1.018, 1.965; P = .039) and gland volume (OR = 0.557; 95% CI: 0.353, 0.880; P = .012) were associated with 12-month relapse, with higher antibody levels conferring a higher likelihood and smaller gland volumes conferring a lower likelihood. Conclusion US-guided HIFU of the thyroid may be a safe and efficacious treatment in patients with persistent or relapsed GD. However, further study is warranted before it can become mainstream for this indication. © RSNA, 2017 Online supplemental material is available for this article.