Microwave Ablation of Symptomatic Benign Thyroid Nodules

Short-and Long-Term Effects on Thyroid Function Tests, Thyroglobulin and Thyroid Autoantibodies

Mehmet Sercan Erturk; Bulent Cekic; Mehmet Celik; Havva Ucar


Clin Endocrinol. 2021;94(4):677-683. 

In This Article

Abstract and Introduction


Objective: Microwave ablation therapy has been attracting great attention due to its advantages such as low complication rate, good cosmetic results and effective nodule shrinking. Although the effect of thermal ablation therapy on the nodule volume reduction rate has been shown several studies, a limited number of papers have been reported for the effects of microwave ablation (MWA) on thyroid function tests. The aim of this study was to investigate the short- and long-term effects of MWA therapy on thyroid function tests (TFTs), thyroglobulin (Tg) and thyroid autoantibodies in euthyroid patients.

Design, Patients and Measurements: Demographic data of the patients, TFTs, Tg, thyroid autoantibodies and thyroid volume of the nodules were recorded before the procedure and follow-up. Any differences in serum thyroid hormone levels were investigated in pre-, post- and 6-month follow-up periods before and after MWA.

Results: The difference between all thyroid hormone levels at pre MWA and 24 h after MWA was statistically significant (p < .001). FT3 (4.62) pmol/L and FT4 (10.81) pmol/L median levels increased significantly (p < .001), while thyrotropin (TSH) levels decreased at 24 h after MWA (p < .001). Thyroid antibodies levels were not statistically different at 6-month (p > .05), whereas Tg levels decreased (p < .001) compared to pre MWA.

Conclusions: While no significant effect was observed at 6 month, the effect of MWA on thyroid function tests was prominent at 24 h.


Management of thyroid nodules (TNs) is a common problem in clinical endocrinology practice. Most TNs are asymptomatic and do not cause thyroid dysfunction.[1,2] Clinical follow-up is recommended for benign non-functioning asymptomatic TNs.[2] Symptoms attributable to compression of adjacent structures by TNs include dysphagia, globus sensation, dysphonia and dyspnea.[3,4] Medical treatments have limited value in the treatment of compression symptoms and cosmetic concerns. Surgery in nodular thyroid diseases is usually preferred in patients with compression symptoms, in the presence of thyroid cancer and in the selected cases with hyperthyroidism.[5] One of the most important priorities in the follow-up and treatment of TNs is to protect the patients from unnecessary surgery.

In the field of minimally invasive therapies, several ultrasound-guided techniques involving percutaneous ethanol injection, percutaneous thermal radiofrequency (RF) and laser ablation (LA) have revealed promising results over the last decade.[6] Recently, microwave ablation (MWA) has been emerging as a new image-guided thermal ablation therapy that helps to relieve compression symptoms and/or cosmetic problems of the nodule.[7]

Acute and excessive discharge of thyroid hormones into the blood may cause thyroid crisis.[8] This is particularly important in patients with comorbidities such as coronary artery disease and arrhythmia. To date, the effect of thermal ablation treatments on nodule shrinkage has been shown in many studies,[5] but there are a limited number of studies evaluating the effects of MWA on thyroid function tests. Heck et al[9] reported in their recent study, in which all patients were evaluated with thyroid scintigraphy and cold nodules were included, that thyroid function tests (TFTs) were not significantly affected. However, function evaluation of TNs with thyroid scintigraphy is not recommended in euthyroid patients. Thus, the purpose of this study is to investigate the short- and long-term effects of MWA therapy on TFTs, thyroglobulin and thyroid autoantibodies in patients with euthyroid nodules where functional evaluation has not been required by management guidelines.