title: Real-time three-dimensional guided ultrasound targeting system for microwave ablation of liver tumours: a human pilot study.
abstract: OBJECTIVE
  This study aimed to evaluate a novel three-dimensional ultrasound (US) guidance system for use in hepatic microwave ablation (MWA).
  
  
  METHODS
  An in vitro assessment was performed in which users with different degrees of experience were evaluated for accuracy in targeting phantom lesions embedded in agar using US alone, or US in conjunction with the InVision™ System (IVS). An eight-patient pilot trial of the IVS was then performed in the setting of open hepatic MWA, in which lesions would otherwise have been targeted with conventional US.
  
  
  RESULTS
  In vitro studies demonstrated that the IVS significantly improved targeting accuracy at all levels of operator experience (novice, beginner and expert). In the human trial, a total of 31 tumours were targeted and all lesions were hit in one pass, as assessed by independent US image observations. There were no adverse operative events; however, there was minor line-of-sight interference with the infra-red tracking mechanism when some lesions high on the dome of the liver were targeted.
  
  
  CONCLUSIONS
  The IVS significantly increased the accuracy of complex targeting procedures of phantom lesions and enhanced targeting in an eight-patient clinical pilot study. During the accrual phase of this pilot study, the development of improved non-optical tracking hardware obviated the requirement to maintain a direct line of sight. The trial was then halted prematurely in order to focus on the application of the IVS utilizing this non-optical modality.
authors.affiliation: Division of Hepatobiliary Surgery, Department of General Surgery, Carolinas Medical Center, Charlotte, NC 28204, USA.
authors.forename: David
authors.initials: D
authors.lastname: Sindram
authors.forename: Ryan Z
authors.initials: RZ
authors.lastname: Swan
authors.forename: Kwan N
authors.initials: KN
authors.lastname: Lau
authors.forename: Iain H
authors.initials: IH
authors.lastname: McKillop
authors.forename: David A
authors.initials: DA
authors.lastname: Iannitti
authors.forename: John B
authors.initials: JB
authors.lastname: Martinie
mesh_terms: D017115:Catheter Ablation / Q000295:instrumentation / Q000379:methods*; D004502:Education, Medical, Continuing; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D008872:Microwaves / Q000627:therapeutic use*; D019047:Phantoms, Imaging; D010865:Pilot Projects; D012984:Software; D013043:Specialties, Surgical / Q000193:education; D018084:Ultrasonography, Interventional / Q000295:instrumentation / Q000379:methods*