Influence factors and nomogram for volume reduction rate in benign thyroid nodule after thermal ablation

Background Thermal ablation is a minimally invasive and safe treatment for benign thyroid nodules, and the volume reduction rate (VRR) of nodule is a primary clinical efficacy indicator. Purpose To screen factors influencing VRR in benign thyroid nodules after thermal ablation and establish a predictable nomogram. Materials and methods This retrospective study enrolled 238 patients with benign thyroid nodules who underwent thermal ablation between January 2016 and September 2021. Clinical information and imaging characteristics in routine ultrasound (US) and contrast-enhanced ultrasound (CEUS) were evaluated. Factors influencing the VRR >= 75% were screened using multivariate logistic regression, and a predictable nomogram was established. Results At the 12-month follow-up, the VRR of nodule was 77.0 +/- 20.6% (18.4-100%). Seven factors influencing the VRR >= 75.0% were identified: echogenicity, component, calcification, enhancement degree, enhancement defect, ring enhancement, and energy of ablation. A nomogram was established based on the above factors, and the predictive ability of the model was confirmed by internal validation with 1000 bootstrap repetitions. The area under the receiver-operating characteristic curve (AUC) of the model was 0.926, and the calibration curve and decision curve analysis (DCA) revealed that this model demonstrated predictive ability. Conclusion Seven factors influencing VRR in benign thyroid nodules after thermal ablation were screened out in the present study and used to establish a nomogram to predict the probability of VRR >= 75% at the 12-month follow-up. It would be beneficial to make personalized medical decisions to trigger thermal ablation in patients with benign thyroid nodules.