SAT511 High Intensity Focused Ultrasound (HIFU) Ablation for Benign Thyroid Nodules: A Single-Center Cohort

Abstract Disclosure: M. Mavromati: None. P. Meyer: None. F. Vermeulen: None. M. Demarchi: None. E. Saiji: None. C. De Vito: None. F. Jornayvaz: None. S. Leboulleux: None. A. Wolff: None. F. Triponez: None. Introduction:Benign thyroid nodules may increase in size over time and cause local compressive symptoms. Current guidelines suggest surgery for benign symptomatic nodules, however, complications such as hypothyroidism, bleeding, infection and recurrent laryngeal nerve injury are of concern for a growing number of patients. Minimally invasive techniques may therefore be an alternative to surgical resection. The objective of our study was to evaluate the efficacy and safety of high intensity focused ultrasound (HIFU) ablation in a single-center cohort of benign symptomatic thyroid nodules.Materials and methods:Between February 2021 and May 2022, 13 patients were treated by HIFU for a single benign solid symptomatic thyroid nodule. Benign nature of thyroid nodules was confirmed by a Bethesda II result in fine-needle aspiration, before HIFU. Treatment was performed under hypnosis, carried out by an experienced anesthesiologist. Patients were evaluated by clinical examination and ultrasound at 6 and 12 months after treatment. Results: A total of 13 patients (12 female and 1 male) were treated with HIFU for a single solid symptomatic benign thyroid nodule. Mean age was 57 years (range: 48-67 years). Thyroid nodules had an mean maximum diameter of 48 mm (range: 31-66 mm) and a meanvolume of 28.4 mL (range: 8.5-53 mL). At 12 months after HIFU, 4 patients underwent surgical ablation (31%) because of nodule growth (n=2, 15.4%) or persistent local compression (n=2, 15.4%). Those nodules were benign on final histology. Among non-operated nodules, mean decrease of volume at 6 months was 35% (range: 20-46%) and smaller nodules showed a better response to treatment. Altogether, 8 patients (61.5%) reported a clinical improvement 6 months after treatment, while 4 patients (31%) underwent surgery. Treatment was well tolerated in the majority of patients and had to be stopped because of pain in only one case (7.7%). There were no treatment-related local complications. Conclusion:High-intensity focused ultrasound (HIFU) ablation for benign symptomatic thyroid nodules is a safe minimally invasive technique but volume reduction was only 20-46% at 6 months, while 31% of patients required surgery after all. This could be attributed to the large initial volume of nodules included in our cohort. Clinical hypnosis is a useful alterative for pain management. Presentation Date: Saturday, June 17, 2023