Radiofrequency ablation of primary thyroid carcinoma: efficacy according to the types of thyroid carcinoma.

OBJECTIVE: To evaluate the efficacy of ultrasound (US)-guided radiofrequency ablation (RFA) according to the types of thyroid carcinoma, particularly in patients with a high-surgical risk.

MATERIALS AND METHODS: Eight patients with nine tumours of pathologically proven papillary and anaplastic carcinoma were treated by US-guided RFA. Patients with primary thyroid carcinoma were divided into three groups; group (1) Anaplastic carcinoma, group (2) papillary macrocarcinoma, and group (3) papillary microcarcinoma. We evaluated changes in clinical symptoms, tumour volume and local tumour recurrence/metastasis after RFA. Patients were followed up at 1, 6 and 12 months and annually thereafter.

RESULTS: Among nine tumours, one anaplastic carcinoma was treated three times and the other anaplastic carcinoma and one papillary macrocarcinoma were treated twice. Group 3 were treated once. The initial mean tumour volume was 107.9 ± 78.6 (with neck bulging), 126.9 (with neck bulging) and 0.16 ± 0.08 mL (without cosmetic or symptomatic problems) in groups 1-3, respectively. Group 1 showed no improvement in clinical symptoms or neck bulging after RFA, whereas group 2 demonstrated a decreased tumour volume measuring 0.7 mL with improved neck bulging. In group 3, mean volume decreased measuring 0.07 ± 0.12 mL. No local tumour recurrence or metastatic lesion was detected during the mean follow-up of 19.3 months in papillary carcinomas. No major complications were encountered.

CONCLUSIONS: In patients with primary thyroid carcinoma, RFA achieved excellent local tumour control for papillary macro- and microcarcinoma; however, its clinical effect on anaplastic carcinoma was questionable.