title: Percutaneous radiofrequency ablation with multiple electrodes for medium-sized hepatocellular carcinomas.
abstract: OBJECTIVE
  To prospectively evaluate the safety and short-term therapeutic efficacy of switching monopolar radiofrequency ablation (RFA) with multiple electrodes to treat medium-sized (3.1-5.0 cm), hepatocellular carcinomas (HCC).
  
  
  METHODS
  In this prospective study, 30 patients with single medium-sized HCCs (mean, 3.5 cm; range, 3.1-4.4 cm) were enrolled. The patients were treated under ultrasonographic guidance by percutaneous switching monopolar RFA with a multichannel RF generator and two or three internally cooled electrodes. Contrast-enhanced CT scans were obtained immediately after RFA, and the diameters and volume of the ablation zones were then measured. Follow-up CT scans were performed at the first month after ablation and every three months thereafter. Technical effectiveness, local progression and remote recurrence of HCCs were determined.
  
  
  RESULTS
  There were no major immediate or periprocedural complications. However, there was one bile duct stricture during the follow-up period. Technical effectiveness was achieved in 29 of 30 patients (97%). The total ablation time of the procedures was 25.4 ± 8.9 minutes. The mean ablation volume was 73.8 ± 56.4 cm(3) and the minimum diameter was 4.1 ± 7.3 cm. During the follow-up period (mean, 12.5 months), local tumor progression occurred in three of 29 patients (10%) with technical effectiveness, while new HCCs were detected in six of 29 patients (21%).
  
  
  CONCLUSIONS
  Switching monopolar RFA with multiple electrodes in order to achieve a sufficient ablation volume is safe and efficient. This method also showed relatively successful therapeutic effectiveness on short-term follow up for the treatment of medium-sized HCCs.
authors.affiliation: Seoul National University Hospital, Seoul 110-744, Korea.
authors.forename: Jung
authors.initials: J
authors.lastname: Lee
authors.forename: Jeong Min
authors.initials: JM
authors.lastname: Lee
authors.forename: Jung-Hwan
authors.initials: JH
authors.lastname: Yoon
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Lee
authors.forename: Se Hyung
authors.initials: SH
authors.lastname: Kim
authors.forename: Jeong Eun
authors.initials: JE
authors.lastname: Lee
authors.forename: Joon Koo
authors.initials: JK
authors.lastname: Han
authors.forename: Byung Ihn
authors.initials: BI
authors.lastname: Choi
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000601:surgery*; D017115:Catheter Ablation / Q000295:instrumentation / Q000379:methods*; D003287:Contrast Media; D018450:Disease Progression; D004566:Electrodes; D005260:Female; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D053208:Kaplan-Meier Estimate; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011446:Prospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D018084:Ultrasonography, Interventional
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide