Clinical study of preutaneous microwave ablation in the treatment of autonomous functional thyroid nodules

Objective To study the clinical efficacy and safety of microwave ablation (MWA) in the treatment of autonomous functional thyroid nodules(AFTN). Methods Sixty-seven nodules of 53 AFTN patients who refused or were not suitable for surgical resection and 131I therapy were enrolled in the study. All the nodules were evaluated by ultrasound, color Doppler flow imaging(CDFI) and contrast enhanced ultrasound(CEUS), and all of them were benign and confirmed by pathology. And then, percutaneous MWA was performed. Fluid isolation and mobile ablation were used to completely inactivate the nodules, and CEUS was used to evaluate the efficacy of the treatment. The following items included thyroid hormone level, nodule volume, nodular blood supply, thyroid radionuclide imaging, conscious symptom, beauty score and complication. Finally, the factors influencing the curative effect were analyzed. Results The follow-up period was at least 12 months. Compared with before treatment, the differences of thyroid hormone level, the volume of nodules, the nodule blood supply were statistically significant (P<0.01). The 61 "hot nodules" changed to "cold or warm nodules" . The differences between the improvement ratio of conscious symptoms and beauty scores were statistically significant(P<0.05). The cure ratio in this study was 81.13%, and the incidence of complications was 11.32%, and the recurrence ratio was 4.48%. The nodule volume≥14.04 ml or in a dangerous position were the main factors affecting the curative effect. Conclusions MWA can inactivate the AFTN in situ, make it lose the secretory function and reduce the volume of nodules. Therefore, percutaneous MWA guided by ultrasound and CEUS treatment of AFTN can be regarded as another safe and effective treatment besides surgical resection or 131I therapy. Key words: Contrast-enhanced ultrasound; Microwave ablation; Thyroid nodules; Clinical efficacy