Comparison of Mono- and Bipolar Radiofrequency Ablation in Benign Thyroid Disease
PURPOSE Pilot studies of combined therapies treating benign nodular goiters reported promising results. The aim of this study was to investigate the effectiveness of combined microwave ablation (MWA) and radioiodine therapy (RIT) with a special focus on thyroid function at the 3-month follow-up. MATERIALS AND METHODS 15 patients (median age: 55 years) with a large goiter and benign thyroid nodules or Graves' disease were treated with the combined therapy. Serum levels of triiodothyronine (T3), thyroxine (T4), thyrotropin (TSH), thyroglobuline (Tg) and, additionally, antibody levels against thyroglobulin (TgAb), thyrotropin receptors (TRAb) and thyroid peroxidase (TPOAb) were measured at enrollment, post MWA and at the 3-month follow-up (3MFU). Furthermore, the goiter volume, I-131 dose and hospitalization time were analyzed to evaluate effectiveness. MWA was operated under local anesthesia with a system working in a wavelength field of 902 to 928 MHz. RESULTS TSH, T4, T3 and Tg did not change at 3MFU, except for in two patients in whom the initial TSH levels improved to normal thyroid functioning levels at follow-up. One of the patients developed a high TRAb-level that receded back into the normal range. At 3MFU, the combined therapy showed a mean thyroid volume reduction of 26.4 ml ± 7.9 ml (30.5 % ± 4.6 % (p < 0.05)). By utilizing the combined therapy, administered activity could be reduced by 26.6 % ± 4.8 % (p < 0.05) and hospitalization time by 30.9 % ± 19.9 % (p < 0.05). CONCLUSION The data confirmed the effectiveness of the combination of MWA with RIT. The combined therapy is an innovative and conservative approach and could become a safe alternative to surgery for the treatment of very large benign nodular goiters. Due to the short follow-up and the limited number of patients, further studies will be necessary. KEY POINTS • The combined therapy shows a significant volume reduction in benign nodular goiters. • Initial MWA improves the RIT results by reducing the required therapy activity. • Thyroid function is preserved after combined therapy.