Effectiveness of High-intensity Focused Ultrasound (HIFU) Therapy of Solid and Complex Benign Thyroid Nodules – A Long-term Follow up Two-center Study

Abstract Purpose To investigate the effectiveness of high-intensity focused ultrasound (HIFU) of solid and complex benign thyroid nodules. Methods Fifty-eight patients with benign thyroid nodules were treated with HIFU at two centers from 2014–2019. The device, EchoPulse (Teraclion, Malakoff, France), heats the nodes to 80–90 °C. Nodal volumes were measured by ultrasound at regular intervals before and up to 12 months after therapy. In a retrospective long-term two-center study, average volume reductions in relation to baseline volume were statistically analyzed by the Wilcoxon signed-rank test. Side effects were documented. Results In solid nodules, the average percent volume reductions at the 3, 6, 9, and 12-months follow-up were 49.98%, 46.40%, 65.77%, and 63.88%, respectively. The results were significant with p<0.05 in the Wilcoxon signed-rank test at the 3, 6, and 9-months follow-up. In complex nodules, the average percent volume reduction was 35.2% at 3 months, 36.89% at 6 months, and 63.64% at twelve months follow up. The results were significant with p<0.05 in the Wilcoxon signed-rank test at the 3- and 6-months follow-up. The complication rate was 5.2%. All complications occurred in patients with solid nodules. Conclusion The study showed that HIFU is an effective treatment method for both solid and complex nodules. The complication rate is relatively high at 5.2%. No long-term complications occurred. The solid nodules responded better to HIFU than complex nodules.