Longer-term outcomes of radiofrequency ablation for locally recurrent papillary thyroid cancer.

OBJECTIVES: The purpose of this study was to evaluate the longer-term efficacy of ultrasound (US)-guided radiofrequency ablation (RFA) for treating locally recurrent papillary thyroid cancer (PTC).

METHODS: We retrospectively reviewed 29 patients who underwent RFA for 46 recurrent PTC between September 2008 and April 2012 and were subsequently followed up for at least 5 years. Follow-up included size change on US and thyroglobulin (Tg) level at 1, 3, 6, and 12 months and every 6-12 months thereafter. Any complications were reported during follow-up.

RESULTS: The mean follow-up duration after RFA was 80 ± 17.3 months (range, 60-114 months). Tumor volume decreased significantly, from 0.25 ± 0.42 mL before ablation to 0.01 ± 0.08 mL at the final evaluation (p < 0.001), with a mean volume reduction of 99.5% ± 2.9%. Forty-two of the 46 treated tumors (91.3%) had completely disappeared by the final evaluation. The mean serum Tg level decreased from 2.55 ± 4.7 to 0.75 ± 1.83 ng/dL (p < 0.001). There were no delayed complications associated with RFA during the follow-up period.

CONCLUSIONS: RFA seems to be an effective minimally invasive therapy for the treatment of locally recurrent PTC even in the longer-term period.

KEY POINTS: • RFA is an effective local control treatment option for recurrent PTCs even in the longer-term period with mean tumor VRR of 99.5% and the complete disappearance of the treated tumors in 91.3%. • The mean serum Tg level decreased significantly after RFA and biochemical remission rate was 51.7%. • No delayed complication after RFA for local recurrent PTC.