Surgery After Ultrasound-Guided Radiofrequency Ablation for Papillary Thyroid Carcinoma in 21 Patients: A Retrospective Study from a Single Center in China.

BACKGROUND Radiofrequency ablation (RFA) is used to treat various cancers, but its use in thyroid cancer remains controversial. The aim of this study was to investigate surgical findings after RFA for papillary thyroid cancer (PTC). MATERIAL AND METHODS The study included 21 patients (average age 44.9±13.3 years) who had biopsy-confirmed thyroid cancer treated with RFA in multiple hospitals. Surgery was done in the First Hospital of China Medical University. RESULTS The 21 patients had a total of 32 thyroid nodules that were treated with RFA. Twenty-eight nodules were malignant, and 4 nodules were benign. Before RFA, 17 of the malignant nodules were >1 cm and 11 were ≤1 cm. Among the 28 malignant nodules, post-ablation lesions adhered to or invaded the structures surrounding the thyroid in 17 (60.7%), 19 (67.9%), and 22 (78.6%) nodules evaluated with ultrasound, contrast-enhanced computed tomography, and intraoperatively, respectively. Based on pathology results, 7 (33.3%) of the 21 patients had bilateral cancer. Ten (47.6%) of the 21 patients had central lymph node metastasis and 2 (9.5%) had lateral lymph node metastasis. For 5 (15.6%) of the 32 nodules, the fine-needle aspiration results were not consistent with the postoperative pathological results. Five (23.8%) of the 21 patients with lymph node metastasis had clinically negative (CN0) lesions. CONCLUSIONS RFA for PTC primary lesions may be incomplete and leave residual lymph node metastasis, even in lesions ≤1 cm. RFA should be recommended with caution in the treatment of operable patients with primary PTC.