Three-Dimensional Volumetric Ultrasound Assessment of Microwave Ablation Outcomes in Benign Thyroid Nodules

Background: Benign thyroid nodules are common, and although many are asymptomatic, some lead to compressive symptoms or cosmetic concerns requiring intervention. Ultrasound-guided microwave ablation (MWA) has emerged as a minimally invasive alternative to surgery. Accurate assessment of treatment response depends on precise measurement of nodule volume, and three-dimensional (3D) volumetric ultrasonography provides more reliable evaluation than conventional two-dimensional ultrasound.Aim: To assess the efficacy of ultrasound-guided microwave ablation in reducing the volume of benign thyroid nodules using 3D volumetric ultrasonography.Patients and Methods: This single-arm interventional study included 45 patients with benign thyroid nodules treated at Sayed Galal University Hospital between July 2024 and May 2025. All patients underwent baseline laboratory investigations and 3D ultrasonographic volume assessment. Microwave ablation was performed using a trans-isthmic approach and the moving-shot technique. Follow-up 3D ultrasound examinations were conducted at 1 and 3 months post-ablation. Volume reduction ratio (VRR) was calculated, and paired t-tests were used for statistical analysis.Results: The mean baseline nodule volume was 17.18 ± 5.18 mL. Significant volume reduction was observed at both follow-up points: 11.67 ± 3.43 mL at 1 month and 9.7 ± 3.44 mL at 3 months (P < 0.001). The VRR increased progressively, and no major complications occurred. Most nodules were isoechoic (42.22%), complex in texture (42.22%), and showed minimal to mild vascularity. Complications were limited to minor, transient events.Conclusion: MWA is a safe and effective treatment for benign thyroid nodules. Three-dimensional ultrasonography provides accurate monitoring of volume reduction and enhances assessment of treatment response.