Identifying Failure Predictors in Thyroid Nodule Radiofrequency Ablation Using Multivariate Analysis: A Single-Centre Experience.

BACKGROUND Radiofrequency ablation (RFA) has become an established minimally invasive treatment for benign thyroid nodules (BTN), offering excellent safety and efficacy. However, factors predicting treatment success and post-procedural thyroid dysfunction remain incompletely understood. This study aimed to perform a preliminary evaluation of clinical, procedural, and biochemical predictors of RFA outcomes in a real-world consecutive patient cohort. STUDY DESIGN AND METHODS A retrospective analysis was conducted on consecutive patients who underwent ultrasound-guided RFA for cytologically benign thyroid nodules between January 2018 and March 2024 at a single tertiary medical centre. Demographic, sonographic, procedural, and biochemical variables, including thyroid-stimulating hormone (TSH), thyroglobulin (Tg), and anti-Tg antibodies, were analysed. The primary endpoint was the Volume Reduction Ratio (VRR), with ≥ 50% defined as procedural success. RESULTS Sixty-two patients (mean age 52.6 years; 85.5% female) were included. The median best VRR achieved was 61.9% (IQR 46.6-74.5), with 71% of patients attaining ≥ 50% reduction. Higher pre-treatment Tg levels were significantly associated with reduced VRR (p < 0.001) and remained independently associated with procedural failure in an exploratory multivariable model (OR 0.87 per 10 ng/mL increase, p = 0.011). Pretreatment TSH levels showed a univariate positive trend but did not reach statistical significance on multivariate analysis. Two patients (3.2%) developed hypothyroidism post-RFA, both with positive anti-Tg antibodies (total 13 patients had positive anti Tg Ab). The overall complication rate was 6.5%, with no major adverse events. CONCLUSIONS Our results suggest that pre-treatment thyroglobulin levels may serve as a potential biochemical predictor of RFA success in benign thyroid nodules, while antibody positivity may suggest susceptibility to post-ablation hypothyroidism. While most existing literature focuses on imaging features (e.g., sonographic features) or surgeon technique, our findings highlight the unique importance of biochemical characteristics. Incorporating biochemical profiling into pre-procedural assessment could refine patient selection and enhance individualised treatment planning. Future prospective studies are warranted to validate Tg as a biomarker of RFA response.