Radiofrequency Ablation of Thyroid Nodules: A Long-Term Prospective Study of 24 Patients

Clinical question
Can radiofrequency (RF) ablation serve as an alternative treatment modality for managing benign thyroid nodules with compressive or cosmetic symptomatic complaints?

Take away point
RF ablation of benign symptomatic thyroid nodules is safe and effective. It can be an alternative treatment modality to surgical resection for management.

Reference
Martinez, J. et al. Radiofrequency Ablation of Thyroid Nodules: A Long-Term Prospective Study of 24 Patients. Journal of Vascular and Interventional Radiology (JVIR), Volume 30, Issue 10, 1567-1573.

Click for abstract

Study design
Single arm, prospective, cohort study of 24 Caucasian patients with symptomatic benign single thyroid nodules, undergoing RF ablation, interval follow-up until 36 months after treatment.

Funding source
No reported funding

Setting
Academic hospital, Hospital Universitario de Burgos (HUBU), Spain.






Figure 3
Ultrasound image of a nodule displaying intranodular gas after the “pop” in a successful RF ablation treatment. Vigilance should be directed towards the paratracheal “danger triangle” located near the medial and posterior aspect of the nodule.

Summary

Thyroid nodules are extremely common and the majority of these nodules are benign. A small portion may grow over time and can cause cosmetic issues, local compressive symptoms, and anxiety. Traditional treatment involves surgical resection. Ultrasound-guided, minimally invasive, radiofrequency (RF) ablation in an outpatient setting has become available. Literature remained scarce regarding ablation parameters, safety profile, and long-term efficacy on different nodule compositions.

The authors performed a prospective study of 24 Caucasian patients with solitary symptomatic benign solid, solid predominant, or cystic predominant thyroid nodules undergoing RF ablation with a follow-up period of 36 months. Thyroid Imaging Reporting and Data System grades 1 or 2 nodules with two consecutive Bethesda Category II aspiration results were included. Patients were excluded if presented with contralateral laryngeal nerve palsy, presence of pacemaker, pregnancy, cystic nodules, history of neck external beam radiation, or lack of collaborative capacities. RF ablation was performed with a trans-isthmic approach (except for 1 patient) and the moving-shot technique. 30 W power with 3 minute ablation time was initiated followed by 10 W interval increase every 1 minute until the “pop” of the nodule.

The authors found a total complication rate of 16.67%, including 2 local hematomas and 1 large intra-cystic hematoma as well as a major complication of laryngeal nerve damage. The success rate at 12 months after the procedure was 72.22%. Interval follow-up demonstrated an average decrease in nodular size of 32.98% at 1 month and 68.76% at 12 months. Further changes in nodular sizes were minimal afterwards, measuring 76.84% at the 36-month follow-up. A logarithmic correlation was found between nodular size reduction and time. Sub-group analysis revealed more nodular size reduction of solid nodules within the first 6 months while cystic predominant mixed nodules tend to have a smoother curve of nodular size reduction. No significant correlation with ablation parameters including the number of ablations, ablation power, and ablation time was found.

Commentary

The authors in this study quantified the long-term safety profile and treatment efficacy of RF ablation for the management of benign symptomatic solid or mixed thyroid nodules. Their results also suggested a follow-up timeline of 12 months is adequate given the logarithmic correlation between nodular size reduction and time. Additionally, they found no significant correlation of outcome with ablation parameters. These findings support the notion that RF ablation, with a trans-isthmic approach and moving-shot technique, is a safe and effective treatment for benign symptomatic solid or mixed thyroid nodules. At the same time, the findings also highlight the need for larger prospective clincial trials to substantiate the safety profile and long-term role of RF ablation for thyroid nodule management.

Post author

Ningcheng (Peter) Li, MD, MS
Integrated Interventional Radiology Resident, PGY-3
Department of Interventional Radiology
Oregon Health and Science University, Dotter Interventional Institute
@NingchengLi