Percutaneous Microwave Ablation of Metastatic Lymph Nodes from Papillary Thyroid Carcinoma: Preliminary Results.

BACKGROUND: Our purpose is to assess the effectiveness and safety of ultrasound-guided percutaneous microwave ablation (MWA) for lymph node metastases (LNMs) from papillary thyroid carcinomas (PTC). METHODS: In total, 14 patients with recurrent PTC were enrolled in this retrospective study. The vascularity within the ablation zone was evaluated by contrast-enhanced ultrasonography (CEUS) after MWA. Patients were followed up with measurement of the size and volume of tumor, serum thyroglobulin, and clinical evaluation at 7 days, 1, 3, 6 months, and every 6 months thereafter. RESULTS: Twenty-one LNMs were confirmed by biopsy and successfully treated by MWA in a single session. No incomplete ablation was detected by CEUS after treatment. The average largest diameter and volume of the tumors were reduced from 10.1 ± 4.7 mm (range, 3.1-20.0 mm) and 291.9 ± 255.6 mm3 (range, 11.6-766.6 mm3) to 0.9 ± 1.6 mm (range, 0-4.1 mm; p < 0.05) and 4.0 ± 9.0 mm3 (range, 0-31.6 mm3; p < 0.05) at the final follow-up. Neither progression of treated tumors nor newly suspicious LNMs could be detected after treatment. The overall complication rate was 7.1% (1/14). CONCLUSIONS: Ultrasound-guided MWA can effectively control LNMs from PTC, but it is less safe for tumors in the central compartment. MWA may become an alternative therapy in selected PTC patients, who were ineligible or refused to undergo repeated neck explorations.