Comparison of high intensity focused ultrasound and radioiodine for treating toxic thyroid nodules

Purpose: We compared the effectiveness of high intensity focused ultrasound (HIFU) and radioiodine (RAI) to treat patients carrying toxic thyroid nodule (TTN). Normalization of serum thyrotropin (TSH) 1 year after treatment was the primary end-point; concurrent changes in nodules' volume and scintigraphic pattern were also evaluated as secondary end-points. Materials and Methods: Among patients ≥18 years old with TTN observed at our centre between January 1st, 2016 and December 31th, 2016 we prospectively enrolled 17 and 15 age and sex-matched patients treated with RAI and HIFU, respectively. Biochemical thyroid tests and nodules' volume were assessed before and 3, 6 and 12 months after treatments. A thyroid scintigraphy was performed before and 1 year after treatment, respectively. Results: The final series included 17 patients treated with RAI and 15 patients treated with HIFU, respectively. Neither demographic nor clinical differences were found at baseline. One year after treatment 14 of 17 RAI-treated and 4 of 15 HIFU-treated patients fulfilled criteria for response to treatment (P =.0008). Indeed, the median TSH value was 1.5 IU/mL and 0.2 IU/mL in HIFU and RAI groups, respectively (P <.0001). Finally, despite a similar decrease in nodules' volume in both groups, a scintigraphic response was achieved in 16 of 17 (94%) RAI-treated compared to 8 of 15 (53%) HIFU-treated patients (P =.024), respectively. Conclusions: In our series, RAI clearly outperforms HIFU in treating patients carrying TTN and remains the first-line noninvasive treatment in such cases.