title: Radiofrequency ablation combined with chemoembolization for the treatment of hepatocellular carcinomas 5 cm or smaller: risk factors for local tumor progression.
abstract: OBJECTIVE
  To investigate the risk factors for local tumor progression after radiofrequency (RF) ablation combined with chemoembolization for the treatment of hepatocellular carcinoma (HCC).
  
  
  METHODS
  A total of 255 HCC lesions 5 cm or less in maximum diameter were treated by RF ablation in 173 patients within 2 weeks after chemoembolization was performed. Therapeutic response was evaluated by contrast medium-enhanced computed tomography studies. The disappearance of tumor enhancement was considered to indicate complete necrosis. Local tumor progression was defined by the appearance of enhanced tumor adjacent to the zone of ablation. The risk factors for local tumor progression after RF ablation were retrospectively assessed by univariate and multivariate analyses.
  
  
  RESULTS
  All tumors showed complete necrosis after RF ablation. Local tumor progression was found in 18 of the 255 lesions (7%) during a mean follow-up period of 23 months (range, 1-63 months). The cumulative local tumor progression rate was 12% at 5 years. Larger tumor (3.1-5 cm), infiltrating tumor, and previous treatments were found to increase the risk of local tumor progression in univariate and multivariate analyses.
  
  
  CONCLUSIONS
  The combination of chemoembolization with RF ablation is an effective treatment to control HCC lesions. The factors identified in the present study may help to predict the therapeutic response.
authors.affiliation: Department of Radiology, Mie University School of Medicine, 2-174 Edobashi, Tsu, Mie, Japan. takaki-h@clin.medic.mie-u.ac.jp
authors.forename: Haruyuki
authors.initials: H
authors.lastname: Takaki
authors.forename: Koichiro
authors.initials: K
authors.lastname: Yamakado
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Nakatsuka
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Fuke
authors.forename: Kazumoto
authors.initials: K
authors.lastname: Murata
authors.forename: Katsuya
authors.initials: K
authors.lastname: Shiraki
authors.forename: Kan
authors.initials: K
authors.lastname: Takeda
mesh_terms: D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D017115:Catheter Ablation; D016461:Chemoembolization, Therapeutic; D003131:Combined Modality Therapy; D003287:Contrast Media; D018450:Disease Progression; D005260:Female; D006801:Humans; D007472:Iohexol; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D003287:Contrast Media; D007472:Iohexol