title: Clinical utility of multipolar ablation with a 3-D simulator system for patients with liver cancer.
abstract: OBJECTIVE
  The aim of this study is to confirm the efficacy of multipolar ablation with a new simulator system, three-dimensional (3-D) sim-Navigator, for patients with hepatocellular carcinoma by assessing relapse-free survival and shape of the ablation volume under clinical conditions.
  
  
  METHODS
  All participants provided written, informed consent, and study protocols were approved by the institutional ethics committee. Twenty-seven patients with 27 nodules were treated by no-touch ablation using the new simulator system. Another 21 patients with 21 nodules treated without the simulator system were enrolled as controls. Tumor progression and shape of ablation volume were assessed. Predictors of tumor progression were assessed by Cox proportional hazard model.
  
  
  RESULTS
  No significant differences in clinical characteristics were seen between groups. Mean sphericity was 0.48 ± 0.07 with 3-D sim-Navigator and 0.37 ± 0.07 without 3-D sim-Navigator (P < 0.001). Median surface-to-volume ratio and compactness were also significantly closer to those of a sphere with 3-D sim-Navigator (P = 0.017, P < 0.001). Relapse-free survival rates at 1 and 1.5 years were 94.1% and 82.4%, respectively, with 3-D sim-Navigator, compared with 83.2% and 55.5% without (P = 0.056). The only independent factor predicting relapse-free survival was use of 3-D sim-Navigator (hazard ratio, 0.12; 95%CI, 0.01-0.87; P = 0.035).
  
  
  CONCLUSIONS
  Ideal ablation area was acquired by this simulation and navigation system in clinics. This system improved local tumor progression by facilitating appropriate insertion of multiple electrodes.
authors.affiliation: Department of Gastroenterology and Metabology, Ehime University Graduate School of Medicine, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Hirooka
authors.affiliation: Department of Gastroenterology and Metabology, Ehime University Graduate School of Medicine, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Koizumi
authors.affiliation: Department of Gastroenterology and Metabology, Ehime University Graduate School of Medicine, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Imai
authors.affiliation: Department of Gastroenterology and Metabology, Ehime University Graduate School of Medicine, Japan.
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Nakamura
authors.affiliation: Department of Gastroenterology and Metabology, Ehime University Graduate School of Medicine, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yukimoto
authors.affiliation: Department of Gastroenterology and Metabology, Ehime University Graduate School of Medicine, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Department of Gastroenterology and Metabology, Ehime University Graduate School of Medicine, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Yoshida
authors.affiliation: Department of Gastroenterology and Metabology, Ehime University Graduate School of Medicine, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Tokumoto
authors.affiliation: Department of Gastroenterology and Metabology, Ehime University Graduate School of Medicine, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Abe
authors.affiliation: Department of Gastroenterology and Metabology, Ehime University Graduate School of Medicine, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Hiasa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000401:mortality / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods* / Q000401:mortality; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods* / Q000401:mortality; D008113:Liver Neoplasms / Q000401:mortality / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D025321:Surgery, Computer-Assisted / Q000379:methods* / Q000401:mortality; D016896:Treatment Outcome
keywords: 3-D imaging; ablation techniques; hepatocellular carcinoma