Objective: To investigate the technical feasibility, safety and clinical significance of using bi-polar radiofrequency ablation(RFA) for treating thyroid cancer recurrence(TCR) in neck lymph nodes(LNs) under contrast-enhanced ultrasound(CEUS) guidance.
Methods: From March 2006 through December 2008, 34 patients with neck LNs suspicious of TCR 0.7 to 72 months post-thyroidectomies received RFA. Before RFA all patients were assessed through CEUS, 3-D volume calculation and biopsy of LNs. A local anesthesia was delivered. A bi-polar electrode, 19-gauge in diameter, compatible with auto-controlled RF generator was used. Ablation power was 5 watts. Free-hand skills was adopted to introduce electrode into LN under CEUS-guidance. While the LNs were adjacent to CCA or IJV, 10 ml saline was injected into between to separate them for safe introducing.
Results: 113 LNs were ablated and 102 of them were histological papillary thyroid cancer. The maximum diameter and number of the ablated LNs were 5.3 mm to 26.4 mm and 1 to 5 one time respectively. Before RFA 83.3% of the patients had a notable increase in serum TGA while 67.4%,82.2% and 97.5% of the elevated TGA declined at 1, 2, 4 weeks after RFA. CEUS post-RFA demonstrated all the ablated LNs turned into non-enhancement from pre-RFA hyperenhancement. Significant decrease in LNs volume took place since the 6th week post-RFA. There was neither injury to the major blood vessels nor damage to recurrent laryngeal nerve.
Conclusion: CEUS-guided bi-polar RFA is readily to operate technically and safe electrically. It can be an alternative to surgical resection for neck LN recurrecnce.