Ultrasound-Guided Radiofrequency Ablation Versus Thyroid Lobectomy for Low-Risk Papillary Thyroid Microcarcinoma: A Propensity-matched Cohort Study of 884 Patients.

Abstract

BACKGROUND\nThermal ablation (TA) has been applied in patients with low-risk papillary thyroid microcarcinoma (PTMC) who refuse surgery or active surveillance (AS). Recently, TA is also proposed as a potential therapeutic option for patients who are suitable for surgery or AS. However, the clinical outcomes of TA versus surgery remains controversial because of lacking sufficient data. This study aimed to compare the clinical outcomes between radiofrequency ablation (RFA) versus thyroid lobectomy (TL) for low-risk PTMC in a large cohort.\n\n\nMETHODS\nThis retrospective study evaluated 884 patients with unifocal low-risk PTMC treated with TL or RFA from June 2014 to March 2018. Among them, 460 patients underwent TL(TL group) and 424 who refused surgery or AS underwent RFA(RFA group). Patients were regularly followed up after treatment. Local tumor progression, recurrence-free survival (RFS), complications and treatment variables, including procedure time, estimated blood loss, hospitalization and cost, were compared after propensity score matching(PSM).\n\n\nRESULTS\nAfter PSM, a total of 332 patients underwent TL (mean ages, 43.8 ± 9.5 years) and 332 underwent RFA (mean ages, 44.1 ± 9.5 years). During the follow-up (median [interquartile ranges], 48.3 [23.2] months), no significant differences were observed in the local tumor progression (1.8% vs. 3.3%, P=.209), lymph node metastasis (0.6% vs. 0.6%, P=1.000), recurrent PTMC (1.2% vs. 2.4%, P=.244), persistent lesion (0% vs. 0.3%, P=.317) and 4-year RFS rates (98.2% vs. 97.0%, P=.223) between the TL and RFA groups. Distant metastasis was not detected. None of the patients who were treated by RFA underwent delayed surgery. Patients undergoing RFA had shorter procedure time (3.4 [2.5] vs. 86.0 [37.0] min , P<.001), lower estimated blood loss (0 vs. 20[10.0] mL, P<.001), shorter hospitalization (0 vs. 7.0[3.0] d, P<.001), lower cost ($2035.7 [254.0] vs. $2269.1 [943.4], P<.001) and lower complication rate (0% vs. 4.2%, P<.001) than those treated by TL. The association between treatment modality and recurrence remained nonsignificant after Cox analysis (P=.247).\n\n\nCONCLUSIONS\nThis large, matched study revealed comparable 4-year clinical outcomes between RFA and TL for low-risk PTMC. As a minimally invasive modality, RFA may be a promising complementary to the existing treatment for low-risk PTMC.