title: Endoscopic high-intensity focused US: technical aspects and studies in an in vivo porcine model (with video).
abstract: BACKGROUND
  High-intensity focused US (HIFU) is becoming more widely used for noninvasive and minimally invasive ablation of benign and malignant tumors. Recent studies suggest that HIFU can also enhance targeted drug delivery and stimulate an antitumor immune response in many tumors. However, targeting pancreatic and liver tumors by using an extracorporeal source is challenging due to the lack of an adequate acoustic window. The development of an EUS-guided HIFU transducer has many potential benefits including improved targeting, decreased energy requirements, and decreased potential for injury to intervening structures.
  
  
  OBJECTIVE
  To design, develop, and test an EUS-guided HIFU transducer for endoscopic applications.
  
  
  METHODS
  A preclinical, pilot characterization and feasibility study.
  
  
  METHODS
  Academic research center.
  
  
  METHODS
  Studies were performed in an in vivo porcine model.
  
  
  METHODS
  Thermal ablation of in vivo porcine pancreas and liver was performed with EUS-guided focused US through the gastric tract.
  
  
  RESULTS
  The transducer successfully created lesions in gel phantoms and ex vivo bovine livers. In vivo studies demonstrated that targeting and creating lesions in the porcine pancreas and liver are feasible.
  
  
  CONCLUSIONS
  This was a preclinical, single-center feasibility study with a limited number of subjects.
  
  
  CONCLUSIONS
  An EUS-guided HIFU transducer was successfully designed and developed with dimensions that are appropriate for endoscopic use. The feasibility of performing EUS-guided HIFU ablation in vivo was demonstrated in an in vivo porcine model. Further development of this technology will allow endoscopists to perform precise therapeutic ablation of periluminal lesions without breaching the wall of the gastric tract.
authors.affiliation: Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA.
authors.forename: Tong
authors.initials: T
authors.lastname: Li
authors.affiliation: Division of Gastroenterology, Department of Medicine, University of Washington, Seattle, Washington, USA; Applied Physics Laboratory, University of Washington, Seattle, Washington, USA.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Khokhlova
authors.affiliation: Department of Radiology, University of Washington, Seattle, Washington, USA.
authors.forename: Ezekiel
authors.initials: E
authors.lastname: Maloney
authors.affiliation: Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA.
authors.forename: Yak-Nam
authors.initials: YN
authors.lastname: Wang
authors.affiliation: Division of Gastroenterology, Department of Medicine, University of Washington, Seattle, Washington, USA; Applied Physics Laboratory, University of Washington, Seattle, Washington, USA.
authors.forename: Samantha
authors.initials: S
authors.lastname: D'Andrea
authors.affiliation: Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, Washington, USA.
authors.forename: Frank
authors.initials: F
authors.lastname: Starr
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, Washington, USA.
authors.forename: Navid
authors.initials: N
authors.lastname: Farr
authors.affiliation: Sonic Concepts, Bothell, Washington, USA.
authors.forename: Kyle
authors.initials: K
authors.lastname: Morrison
authors.affiliation: Sonic Concepts, Bothell, Washington, USA.
authors.forename: George
authors.initials: G
authors.lastname: Keilman
authors.affiliation: Division of Gastroenterology, Department of Medicine, University of Washington, Seattle, Washington, USA.
authors.forename: Joo Ha
authors.initials: JH
authors.lastname: Hwang
mesh_terms: D000818:Animals; D002417:Cattle; D019160:Endosonography; D005240:Feasibility Studies; D057086:High-Intensity Focused Ultrasound Ablation / Q000379:methods*; D008099:Liver / Q000000981:diagnostic imaging*; D010179:Pancreas / Q000000981:diagnostic imaging*; D019047:Phantoms, Imaging; D010865:Pilot Projects; D013552:Swine; D014159:Transducers