Radiofrequency Ablation of Unifocal Papillary Thyroid Microcarcinoma With BRAF V600E Mutation.

CONTEXT: To date there is no study on the feasibility of radiofrequency ablation (RFA) for papillary thyroid microcarcinomas (PTMCs) with BRAF V600E mutation.

OBJECTIVE: This study was designed to evaluate the efficiency, safety, and prognosis of ultrasound (US)-guided percutaneous RFA for unifocal PTMCs with BRAF V600E mutation.

MATERIALS AND METHODS: Sixty patients with 60 unifocal BRAF V600E mutation-positive PTMCs who received US-guided RFA between January 2020 and December 2021 were retrospectively analyzed. The mean maximum PTMC tumor diameter was 5.8 ± 1.7 mm (range, 2.5-10.0 mm). All PTMCs were pathologically confirmed by fine needle aspiration or core needle biopsy, and BRAF V600E mutation was confirmed to be positive by real-time fluorescent quantitative polymerase chain reaction. Contrast-enhanced ultrasound (CEUS) was performed immediately after RFA to evaluate whether PTMCs were extendedly ablated. Ultrasound was performed 1, 3, 6, and 12 months after RFA and every 6 months thereafter to evaluate the changes in the ablation zone, local recurrence, and cervical lymph node metastasis (LNM). The complications were recorded and evaluated.

RESULTS: Extended ablation was achieved in all enrolled patients. The ablation zone sizes increased immediately after RFA compared with those of tumors before treatment. One month later, the ablation zone sizes were smaller than immediately after RFA. At the last follow-up assessment, 42 nodules (70.0%) completely disappeared and the ablation zones of 18 nodules (30.0%) showed fissure-like changes. No local recurrence or cervical LNM was detected. Voice change (1.7%) was the only major complication.

CONCLUSION: RFA is effective and safe in treating unifocal PTMCs with BRAF V600E mutation, especially when surgery is not feasible or refused by patients who are unwilling to continue active surveillance.