Efficacy and Safety of Radiofrequency Ablation for Treatment of Locally Recurrent Thyroid Cancers Smaller than 2 cm.

Purpose: To evaluate the efficacy and safety of radiofrequency ablation (RFA) for localized small recurrent thyroid cancers less than 2 cm by comparing them with those at repeat surgery. Materials and Methods: This retrospective study was institutional review board-approved, and informed consent was waived. From December 2008 to December 2011, this study evaluated 73 patients (17 men and 56 women; age, 50.3 years +/- 13.6) with recurrent thyroid cancer who had been treated with RFA (n = 27) or repeat surgery (n = 46) who met the following criteria: (a) three or fewer recurrences or lesions with high probability of recurrence at ultrasonography; (b) no tumor other than the target tumors; and (c) at least 1 year of follow-up. RFA was recommended and performed in cases of surgical ineligibility, such as patient refusal and poor medical condition. Recurrence-free survival rates and posttreatment complication rates (eg, hoarseness and hypocalcemia) were compared between RFA and reoperation groups after adjustment with weighted analysis by using inverse probability of treatment weights. Results: After this adjustment, the 1- and 3-year recurrence-free survival rates were comparable (P = .681) for RFA (96.0% and 92.6%, respectively) and reoperation (92.2% and 92.2%, respectively) groups. The posttreatment hoarseness rate did not differ between the RFA (7.3% [1.8 of 24]) and reoperation (9.0% [3.6 of 39.5]) groups (P = .812), and posttreatment hypocalcemia occurred exclusively in the reoperation group (11.6% [4.6 of 39.5]) but not in the RFA group (0% [0 of 24]) (P = .083). Conclusion: RFA may be an effective and safe alternative to repeat surgery in patients with locally recurrent small thyroid cancers. (C) RSNA, 2015