Long-Term Results of Ultrasound-Guided Radiofrequency Ablation of Benign Thyroid Nodules: State of the Art and Future Perspectives—A Systematic Review

Abstract

BackgroundNearly 20 years after the first feasibility study, minimally invasive ultrasound (US)-guided therapeutic techniques are now considered as a safe and effective alternative to surgery for symptomatic benign thyroid nodules. Radiofrequency ablation (RFA) is one of the most widely used treatment in specialized thyroid centers but, due to the relatively recent introduction into clinical practice, there are limited long-term follow-up studies. Aim of our work was to review the outcomes of RFA on solid nonfunctioning and on autonomous thyroid nodules (AFTN) on a long-time period for assessing the results in term of efficacy, complications, and costs and to compare them to the current indications of RFA.MethodsA systematic review was performed using EMBASE and Medline library data between 2008 and 2021. Seventeen studies evaluated RFA for the treatment of benign solid (nonfunctioning or autonomous) thyroid nodules, with an at least 18 months of follow-up. Data extraction and quality assessment were performed by two endocrinologist according to PRISMA guidelines. Anthropometric data, safety and efficacy parameters were collected.ResultsThe majority of the studies was retrospective study and reported 933 nodules, mostly solid. Baseline volume ranged between 6.1 ± 9.6 and 36.3 ± 59.8 ml. Local analgesia was used and the time duration of the treatment was between 5 ± 2 and 22.1 ± 10.9 min. The volume reduction rate at 12 months ranged from 67% to 75% for the nodule treated with a single procedure and reached to 93.6 ± 9.7% for nodules treated with repeat ablations. The regrowth rate at 12 months ranged from 0% to 34%.ConclusionAll the studies under examination consistently validated the long-term clinical efficacy and the substantial safety of RFA for the treatment of benign thyroid nodules. Thermal ablation, however, is an operator-dependent technique and should be performed in centers with specific expertise. The selection of the patients should be rigorous because the nodule size and the structural and functional characteristics influence the appropriateness and the outcomes of the treatment. Future perspectives as the treatment of micro-papillary thyroid cancer or cervical recurrence need further investigations.

A New Perspective for Predicting the Therapeutic Success of RFA in Solid BTNs: Quantitative Initial RFA Ratio by Contrast-Enhanced Ultrasound

“…During the 12-month follow-up period, careful examination was required for early signs of nodular regrowth (or marginal regrowth), including a thickness of viable tissue within the nodules exceeding 10 mm on CEUS. Regrowth was defined as an increase in nodule volume of 50% compared to that at the previous examination ( 15 , 25 ). CEUS was used to detect the ablative volume reduction and to assess early signs of nodular recurrence.…”

Efficacy and Safety of Radiofrequency Ablation for Benign Thyroid Nodules: Initial Mongolian Experience

“…Nevertheless, RFA has not yet been unanimously included in all international guides on standard management of thyroid nodules [35]. The efficacy of RFA can be assessed based on different parameters such as percentage volume reduction, the proportion of nodules with therapeutic success (volume reduction > 50 %), and the reduction or disappearance of compression symptoms [36].…”

Transitioning from Traditional Academic Decision Making to Patient-Centric Healthcare Choices: The Example of Thyroid Thermal Ablation Techniques for Papillary Thyroid Microcarcinomas

“…The results are very satisfying, with a volume reduction of 75 to 85% at one year follow-up and an acceptable low regrowth percentage (known to be more frequent using LA). Thyroid nodule regrowth is mostly seen in nodules incompletely treated due to their location or volume [3]. As a matter of fact, a thyroid nodule with a volume >40 mL will indeed require at least two successive percutaneous procedures.…”