title: Switching Monopolar Radiofrequency Ablation Using a Separable Cluster Electrode in Patients with Hepatocellular Carcinoma: A Prospective Study.
abstract: OBJECTIVE
  This study was conducted to evaluate the outcomes of multi-channel switching RFA using a separable cluster electrode in patients with HCC.
  
  
  METHODS
  From November 2011 to July 2013, 79 patients with 98 HCCs < 5 cm were enrolled and treated with RFA using a multi-channel switching radiofrequency system and a separable cluster electrode under the guidance of a real-time fusion imaging system. The primary and secondary endpoints were the 3-year local tumor progression (LTP) rate and recurrence-free survival (RFS) rate, respectively. For post hoc analyses, LTP, RFS, and major complication rates were retrospectively compared with a historical control group treated with RFA using the same radiofrequency system but with multiple internally-cooled electrodes.
  
  
  RESULTS
  The technique success rate of the 98 tumors was 100%. Cumulative 1-year, 2-year, and 3-year LTP rates were 3.4%, 6.9%, and 12.4%, respectively. For patient-level data, cumulative 1-year, 2-year, and 3-year RFS rates were 83.9%, 68.6%, and 45.4%, respectively. On post hoc analyses, none of the baseline characteristics showed a significant difference between the separable cluster electrode and multiple internally-cooled electrodes group. Cumulative LTP and RFS rates of the two groups also showed no significant difference (p = 0.401 and p = 0.881, respectively). Finally, major complication rates of the separable cluster electrode group (5.0%, 4/79) and multiple internally-cooled electrodes group (5.9%, 4/74) were also comparable (p = 1.000).
  
  
  CONCLUSIONS
  Switching monopolar RFA using a separable cluster electrode is a feasible and efficient technique for the treatment of HCCs smaller than 5 cm, providing comparable local tumor control to multiple internally-cooled electrodes.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT02745483.
authors: Department of Radiology, Seoul National University Hospital, Seoul, Korea.
authors: Jin Woo
authors: JW
authors: Choi
authors: Department of Radiology, Seoul National University Hospital, Seoul, Korea.
authors: Jeong Min
authors: JM
authors: Lee
authors: Department of Radiology, Seoul National University Hospital, Seoul, Korea.
authors: Dong Ho
authors: DH
authors: Lee
authors: Department of Radiology, Seoul National University Hospital, Seoul, Korea.
authors: Jeong-Hee
authors: JH
authors: Yoon
authors: Department of Surgery, Seoul National University Hospital, Seoul, Korea.
authors: Kyung-Suk
authors: KS
authors: Suh
authors: Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
authors: Jung-Hwan
authors: JH
authors: Yoon
authors: Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
authors: Yoon Jun
authors: YJ
authors: Kim
authors: Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
authors: Jeong-Hoon
authors: JH
authors: Lee
authors: Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
authors: Su Jong
authors: SJ
authors: Yu
authors: Department of Radiology, Seoul National University Hospital, Seoul, Korea.
authors: Joon Koo
authors: JK
authors: Han
mesh_terms: D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000601:surgery*; D017115:Catheter Ablation / Q000295:instrumentation*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016896:Treatment Outcome