Ultrasound-guided microwave ablation (MWA) is a safe and effective procedure for treating thyroid nodules, suggest findings published September 22 in Academic Radiology.
Researchers led by Uluhan Eryuruk, MD, from Giresun University in Turkey reported significant volume reduction for both solitary nodules and multinodular goiters. They also found that energy delivery per mL, nodule composition, and the presence of calcification are significant independent predictors of volume reduction.
“Furthermore, MWA shows promise as a viable treatment option for autonomously functioning thyroid nodules,” Eryuruk and co-authors wrote.
Previous studies highlight radiofrequency ablation’s effectiveness, but the researchers noted that data on MWA is “relatively limited.” They also wrote that the current literature focuses on the treatment of solitary nodules.
The Eryuruk team studied MWA’s efficacy and safety for treating benign thyroid nodules. This included comparing volume reduction rates between solitary nodules and multinodular goiters, as well as assessing autonomously functioning thyroid nodules.
The single-center retrospective study included 112 patients with an average age of 58 years who were treated with MWA in 2023 and 2024. The team performed routine ultrasound and clinical evaluations at three, six, and 12 months after the procedure. It also defined technical efficacy as a 50% or more reduction in the initial nodule volume after ablation.
The researchers reported a median initial nodule volume of 10.66 mL and found the following:
50 ablations (44.6%) targeted solitary nodules and 62 targeted (55.4%) multinodular goiters.
The median volume reduction rate was 62.9% at three months, 80.5% at six months, and 88.2% at 12 months.
MWA achieved technical efficacy in 94.6% of nodules at 12 months.
Volume reduction rates between solitary nodules and multinodular goiters did not achieve statistical significance at any follow-up interval (12-month rate: 89.0% versus 87.5%, p = 0.973).
On multivariate analysis, the team reported the following factors as significant independent predictors of volume reduction rate: presence of calcification, nodule composition, and energy delivered per mL (p < 0.001 for all).
Of the 18 patients with autonomously functioning thyroid nodules, 11 required antithyroid medication before treatment. Following MWA, seven of these patients successfully stopped medication and maintained euthyroidism (p < 0.001). Finally, the team observed no major complications.
The results point toward MWA being a “robust technique equally effective” for both solitary nodules and multinodular goiters, the study authors highlighted.
“The high [volume reduction rate] achieved in multinodular goiters indicates that MWA can induce substantial necrosis across multiple nodules, offering a viable minimally invasive treatment option,” they wrote.
The authors also called for future prospective, multicenter studies with extended follow-up to validate and expand upon their findings.
Read the full study here.
![Examples of ultrasound findings and techniques. (A) Images in a 39-year-old male patient with a mass in the left thigh. The mass is heterogeneous on the B-mode US image (compared with the patient in D) and showed increased microvascularity (superb microvascular imaging [SMI]) and shear-wave elastography (SWE) values. Undifferentiated pleomorphic sarcoma was diagnosed at biopsy (with pleomorphic rhabdomyosarcoma in surgical specimen). (B) Images in an 18-year-old male patient with a mass in the left leg. The mass is hypoechoic on the B-mode image, with no other findings suggestive of malignancy. The lesion is in contact with the cortex of the tibia, which is slightly irregular. CT revealed a doubtful anteromedial tibial erosion. The microvascular study demonstrated high vascularization, suggestive of malignancy. Periosteal Ewing sarcoma was diagnosed with both histologic and immunohistochemical confirmation. (C) Images in a 69-year-old female patient with a lump growing on the outside of the left leg. Multiple SWE examinations were performed (please note the high values obtained in the measurements, whereas the color map highlights the stiffness relative to adjacent tissues). SMI showed areas of increased vascularization to target for sampling. Undifferentiated spindle cell sarcoma was diagnosed at biopsy, with residual leiomyosarcoma in the surgical specimen after neoadjuvant therapy. (D) Images in a 56-year-old female patient with a mass in the right thigh. The mass is heterogeneous at both B-mode ultrasound (similar to patient A) and MRI (coronal T2-weighted spectral attenuated inversion recovery [SPAIR]; T1-weighted pre-contrast and postcontrast imaging), which even shows uptake after the administration of paramagnetic contrast material, which is traditionally suggestive of malignancy. Low values at SMI and elastography are suggestive of benignity. Spindle cell lipoma was diagnosed at biopsy, with atypical spindle cell lipomatous tumor in the surgical specimen.](https://img.auntminnie.com/mindful/smg/workspaces/default/uploads/2026/08/images-radiol250278fig2.APCFLSvX6p.jpg?auto=format%2Ccompress&fit=crop&h=100&q=70&w=100)
![Examples of ultrasound findings and techniques. (A) Images in a 39-year-old male patient with a mass in the left thigh. The mass is heterogeneous on the B-mode US image (compared with the patient in D) and showed increased microvascularity (superb microvascular imaging [SMI]) and shear-wave elastography (SWE) values. Undifferentiated pleomorphic sarcoma was diagnosed at biopsy (with pleomorphic rhabdomyosarcoma in surgical specimen). (B) Images in an 18-year-old male patient with a mass in the left leg. The mass is hypoechoic on the B-mode image, with no other findings suggestive of malignancy. The lesion is in contact with the cortex of the tibia, which is slightly irregular. CT revealed a doubtful anteromedial tibial erosion. The microvascular study demonstrated high vascularization, suggestive of malignancy. Periosteal Ewing sarcoma was diagnosed with both histologic and immunohistochemical confirmation. (C) Images in a 69-year-old female patient with a lump growing on the outside of the left leg. Multiple SWE examinations were performed (please note the high values obtained in the measurements, whereas the color map highlights the stiffness relative to adjacent tissues). SMI showed areas of increased vascularization to target for sampling. Undifferentiated spindle cell sarcoma was diagnosed at biopsy, with residual leiomyosarcoma in the surgical specimen after neoadjuvant therapy. (D) Images in a 56-year-old female patient with a mass in the right thigh. The mass is heterogeneous at both B-mode ultrasound (similar to patient A) and MRI (coronal T2-weighted spectral attenuated inversion recovery [SPAIR]; T1-weighted pre-contrast and postcontrast imaging), which even shows uptake after the administration of paramagnetic contrast material, which is traditionally suggestive of malignancy. Low values at SMI and elastography are suggestive of benignity. Spindle cell lipoma was diagnosed at biopsy, with atypical spindle cell lipomatous tumor in the surgical specimen.](https://img.auntminnie.com/mindful/smg/workspaces/default/uploads/2026/08/images-radiol250278fig2.APCFLSvX6p.jpg?auto=format%2Ccompress&dpr=2&fit=crop&h=167&q=70&w=250)
