title: Radiofrequency versus Ethanol Ablation for Treating Predominantly Cystic Thyroid Nodules: A Randomized Clinical Trial.
abstract: OBJECTIVE
  To compare single-session radiofrequency ablation (RFA) and ethanol ablation (EA) for treating predominantly cystic thyroid nodules (PCTNs).
  
  
  METHODS
  This single-blind, randomized trial was approved by the Institutional Review Board of two centers and informed consent was obtained from all patients before enrollment. Fifty patients with a single PCTN (cystic portion less than 90% and greater than 50%) were randomly assigned to be treated by either RFA (25 patients) or EA (25 patients) at two hospitals. The primary outcome was the tumor volume reduction ratio (%) at the six-month follow-up and the superiority margin was set at 13% (RFA minus EA). Analysis was performed primarily in an intention-to-treat manner. The secondary outcomes were the therapeutic success rate, improvement of symptomatic and cosmetic problems, and the number of major complications.
  
  
  RESULTS
  The mean volume reduction was 87.5 ± 11.5% for RFA (n = 22) and 82.4 ± 28.6% for EA (n = 24) (p = 0.710; mean difference [95% confidence interval], 5.1% [-8.0 to 18.2]), indicating no significant difference. Regarding the secondary outcomes, therapeutic success (p = 0.490), mean symptom (p = 0.205) and cosmetic scores (p = 0.710) showed no difference. There were no major complications in either group (p > 0.99).
  
  
  CONCLUSIONS
  The therapeutic efficacy of RFA is not superior to that of EA; therefore, EA might be preferable as the first-line treatment for PCTNs.
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea.
authors.forename: Jung Hwan
authors.initials: JH
authors.lastname: Baek
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea. ; Department of Radiology, Ajou University School of Medicine, Suwon 16499, Korea.
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Ha
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea.
authors.forename: Young Jun
authors.initials: YJ
authors.lastname: Choi
authors.affiliation: Department of Radiology, Thyroid Center, Daerim St. Mary's Hospital, Seoul 07442, Korea.
authors.forename: Jin Yong
authors.initials: JY
authors.lastname: Sung
authors.affiliation: Department of Radiology, Chung-Ang University College of Medicine, Seoul 06973, Korea.
authors.forename: Jae Kyun
authors.initials: JK
authors.lastname: Kim
authors.affiliation: Department of Endocrinology and Metabolism, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea.
authors.forename: Young Kee
authors.initials: YK
authors.lastname: Shong
mesh_terms: D000328:Adult; D000368:Aged; D017115:Catheter Ablation; D000431:Ethanol / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016037:Single-Blind Method; D016606:Thyroid Nodule / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000601:surgery*; D016896:Treatment Outcome; D047368:Tumor Burden; D014463:Ultrasonography
chemical_list: D000431:Ethanol
keywords: Ethanol; Predominantly cystic thyroid nodule; Radiofrequency; Thyroid; Ultrasound