Endocrine Abstracts

Background: Ultrasound guided minimally invasive therapies are becoming increasingly popular for the treatment of symptomatic benign thyroid nodules. Efforts have been directed on the prediction of volume reduction as a measure of efficacy of the procedure. Aim of the present study is to identify predictors of 6-months volume reduction rate (VRR) after radiofrequency ablation of benign thyroid nodules.

Materials and Methods: We performed a retrospective single-centre analysis on consecutive patients who underwent radiofrequency ablation for benign thyroid nodules from January 1st 2015 to December 31st 2021. Volume reduction rates were calculated from the preprocedural baseline and collected along with clinical periprocedural and follow up data. Univariate and multivariate linear regression analyses were performed to identify predictors independently associated with the outcome.

Results: A total of 48 patients were included in the analysis, 64,6% of which had compressive symptoms. Median preoperative nodule volume was 16,5 cm3 [IQR 11,1-28,9]. A single patient suffered an intranodular haematoma which was managed conservatively. Symptoms cure was achieved in 77,4% of symptomatic patients, with a median 6 months VRR of 58,8% [IQR 41,7—70,7]. A multivariable linear regression model was computed (P < 0.001; F 7,71) which identified nodule American College of Radiology Thyroid Imaging Reporting and Data Systems (TIRADS) score, preprocedural nodule volume, a diagnosis of toxic or recurrent nodule and Body mass index (BMI) as independent predictors of 6 months VRR (P = 0.006, 0.005, 0.008 and 0.016 respectively). BMI increments were negatively associated with VRR (Coefficient -1,42; 0,016) but not with lower compressive symptoms cure rate at 1 year.

Conclusions: BMI, TIRADS score and nodule volume independently predict VRR although an association with lower symptoms cure rate was not demonstrated. This study adds to the body of literature exploring predictors of radiofrequency ablation efficacy, providing valuable information for clinicians. Prospective multicentre studies are needed to confirm our findings.