Radiofrequency Ablation for Thyroid Papillary Microcarcinoma
Thyroid cancer is projected to be the fourth-leading cancer diagnosis by 2030 (1). The rise in thyroid cancer is likely due to the increased opportunities for detection and management of subclinical disease, including papillary thyroid microcarcinomas (mPTCs), defined as neoplasms measuring 10 mm or less (2,3). Surgery has historically been the therapy of choice, but there are compelling studies reporting excellent oncologic outcomes for surgical alternatives, including active surveillance and thermal ablation. Avoiding surgery can potentially reduce complications such as recurrent laryngeal-nerve injury and harm from overtreatment. Radiofrequency ablation (RFA) is a nonsurgical, minimally invasive technique that uses alternating electromagnetic current to generate molecular frictional heat to destroy cancer cells. Currently, the literature lacks large-scale studies studying the effectiveness of RFA in mPTCs. The primary goal of this article was to analyze the effectiveness and safety of RFA for low-risk mPTC (4).
This meta-analysis included studies with adult patients diagnosed with mPTC treated with RFA. Exclusion criteria included articles with patients with preablation lymph node or distant metastasis, recurrence of disease, or extrathyroidal extension. The meta-analysis was conducted in accordance with the Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines.
A total of 1770 patients from 15 studies were included in the meta-analysis. All studies took place in Asia, including 11 from China and 4 from South Korea. A total of 79% of patients with mPTC who underwent RFA had complete disappearance of tumor tissue on ultrasonography (95% CI, 65–94). Twenty-two patients (1.2%) had FNA-confirmed residual mPTC or a new mPTC. Overall tumor progression was found in 26 patients (1.5%), local residual mPTC in the ablation area was found in 7 tumors (0.4%), new mPTC was found in 15 patients (0.9%), and 4 patients (0.2%) developed lymph node metastases on follow-up. The mean follow-up time was 33 months (range, 6–131). All residual tumors were removed by additional RFA. No patients developed distant metastases. Major complications (defined as temporary voice changes and temporary cardiac arrhythmias during RFA) occurred in 0.17% of patients. All major and minor complications spontaneously resolved within 3 months after RFA treatment.
This study supports that RFA is a potentially safe and efficient tool to treat low-risk mPTCs. Complication rates were low and manageable, typically resolving within 3 months after RFA treatment. Long-term follow-up is needed to determine its oncologic utility in comparison to surgery and active surveillance.