title: Microwave ablation assisted by a real-time virtual navigation system for hepatocellular carcinoma undetectable by conventional ultrasonography.
abstract: OBJECTIVE
  To evaluate the efficiency and feasibility of microwave (MW) ablation assisted by a real-time virtual navigation system for hepatocellular carcinoma (HCC) undetectable by conventional ultrasonography.
  
  
  METHODS
  18 patients with 18 HCC nodules (undetectable on conventional US but detectable by intravenous contrast-enhanced CT or MRI) were enrolled in this study. Before MW ablation, US images and MRI or CT images were synchronized using the internal markers at the best timing of the inspiration. Thereafter, MW ablation was performed under real-time virtual navigation system guidance. Therapeutic efficacy was assessed by the result of contrast-enhanced imagings after the treatment.
  
  
  RESULTS
  The target HCC nodules could be detected with fusion images in all patients. The time required for image fusion was 8-30 min (mean, 13.3 ± 5.7 min). 17 nodules were successfully ablated according to the contrast enhanced imagings 1 month after ablation. The technique effectiveness rate was 94.44% (17/18). The follow-up time was 3-12 months (median, 6 months) in our study. No severe complications occurred. No local recurrence was observed in any patients.
  
  
  CONCLUSIONS
  MW ablation assisted by a real-time virtual navigation system is a feasible and efficient treatment of patients with HCC undetectable by conventional ultrasonography.
authors.affiliation: Department of Interventional Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853, China.
authors.forename: Fang-Yi
authors.initials: FY
authors.lastname: Liu
authors.forename: Xiao-Ling
authors.initials: XL
authors.lastname: Yu
authors.forename: Ping
authors.initials: P
authors.lastname: Liang
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Cheng
authors.forename: Zhi-Yu
authors.initials: ZY
authors.lastname: Han
authors.forename: Bao-Wei
authors.initials: BW
authors.lastname: Dong
authors.forename: Xiao-Hong
authors.initials: XH
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D017115:Catheter Ablation / Q000295:instrumentation / Q000379:methods*; D016461:Chemoembolization, Therapeutic; D003937:Diagnosis, Differential; D004867:Equipment Design; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008872:Microwaves / Q000627:therapeutic use*; D008875:Middle Aged; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional