High-Intensity Focused Ultrasound for Treatment of Symptomatic Benign Thyroid Nodules: A Prospective Study.

Purpose To evaluate first-year efficacy and changes in pressure symptoms and health-related quality of life (HRQOL) after ultrasonographically (US) guided high-intensity focused ultrasound (HIFU) ablation of symptomatic benign thyroid nodules. Materials and Methods After ethics approval and informed consent were obtained, a prospective trial was conducted. Patients with a symptomatic benign thyroid nodule were given a choice of HIFU treatment or active surveillance. Clinical and US examinations, pressure symptom scores (visual analog scale), and HRQOL questionnaires (short form-12 survey) were evaluated at baseline and at 3, 6, and 12 months. The primary outcome was change in nodule volume after 12 months. The percentage of change in nodule volume was defined as the baseline volume minus the volume at 12 months divided by the baseline volume times 100. Ablation success was defined as a reduction in volume of greater than 50%. Nodule volume was compared by using the paired t test. Continuous variables were compared by using the Mann-Whitney U test, and categorical variables were compared by using χ2 tests. Results Twenty-two patients underwent HIFU and 22 underwent active surveillance. Mean age was 53.11 years (range, 28-76 years) and 55.19 years (range, 41-70 years), respectively. The ratio of men to women was 2:20 and 1:21, respectively. The 12-month mean volume reduction ± standard deviation in the HIFU group was significant (68.87% ± 15.27 [range, 47.35%-94.89%], P < .001) but not in the surveillance group (-2.11% ± 6.29 [range, -15.64% to 12.70%], P > .05). Preablation nodule volume was the only determinant of ablation success (odds ratio, 1.877; 95% confidence interval [CI]: 1.085, 3.249; P = .024). At 12 months, patients in the HIFU group had less swelling (P < .001), lower pressure symptom scores (P < .001), and higher physical composite scores (P = .006). Physical composite scores significantly correlated with 6-month reduction in nodule size (r = 0.768; 95% CI: 0.660, 0.930; P < .001) and 12-month reduction in nodule size (r = 0.704; 95% CI: 0.680, 940; P < .001). Conclusion HIFU ablation of symptomatic benign thyroid nodules not only induced significant shrinkage but also improved pressure symptom scores and HRQOL throughout a 12-month period. © RSNA, 2017.