Effect of Ultrasound Parameters of Benign Thyroid Nodules on the Efficacy of Radiofrequency Ablation

Abstract

Introduction: Ultrasound-guided Radiofrequency Ablation (RFA) is a minimally invasive method for treating thyroid nodules (TNs). A good understanding of the factors affecting the efficacy of RFA can help achieve improved treatment efficacy and prognosis. This study investigated the relationship between the ultrasound parameters of benign TNs and the efficacy of RFA in the treatment of these nodules. Methods: An interventional quasi-experimental study at 2021 with a before-and-after design was conducted on 250 randomly sampled patients with benign TNs who were to receive RFA treatment. After RFA, nodule volume reduction (VR) and nodule volume reduction ratio (VRR) were measured at 1-month, 3-month, 6-month, and 1-year follow-ups. Results: VRR at 1-month, 3-month, 6-month, and 1-year follow-ups was 38.7%, 53.6%, 59.3%, and 59.9%, respectively. The mean of VR was statistically significant in all follow-ups (P<0.001). The VR in 28.2%, 52.1%, and 65.2% of nodules were more than 50% at 1-month, 3-month, and 6-month follow-ups respectively. The odds of RFA success were found to be 4.3 times higher for left-lobe nodules than for right-lobe nodules (OR: 4.31, P=0.002), 6.3 times higher for isoechoic nodules than for hyperechoic nodules (OR: 6.39, P<0.001), 6.2 times higher for hypervascular nodules than for hypovascular nodules (OR: 6.25, P=0.005), and 2.3 times higher for mixed nodules than for solid nodules (OR: 2.37, P=0.049). Conclusion: Ultrasound parameters of thyroid nodules were found to have a statistically significant effect on the efficacy of RFA. Small-sized nodules, isoechoic nodules, hypervascular nodules, and nodules with mixed tissue were found to respond better to RFA and thus have a better prognosis in terms of volume reduction after the treatment.