title: Perfusion CT estimates photosensitizer uptake and biodistribution in a rabbit orthotopic pancreatic cancer model: a pilot study.
abstract: OBJECTIVE
  It was hypothesized that perfusion computed tomography (CT), blood flow (BF), blood volume (BV), and vascular permeability surface area (PS) product parameters would be predictive of therapeutic anticancer agent uptake in pancreatic cancer, facilitating image-guided interpretation of human treatments. The hypothesis was tested in an orthotopic rabbit model of pancreatic cancer, by establishing the model, imaging with endoscopic ultrasound (EUS) and contrast CT, and spatially comparing the perfusion maps to the ex vivo uptake values of the injected photosensitizer, verteporfin.
  
  
  METHODS
  Nine New Zealand white rabbits underwent direct pancreas implantation of VX2 tumors, and CT perfusion or EUS was performed 10 days postimplantation. Verteporfin was injected during CT imaging, and the tissue was removed 1 hour postinjection for frozen tissue fluorescence scanning. Region-of-interest comparisons of CT data with ex vivo fluorescence and histopathologic staining were performed.
  
  
  RESULTS
  Dynamic contrast-enhanced CT showed enhanced BF, BV, and PS in the tumor rim and decreased BF, BV, and PS in the tumor core. Significant correlations were found between ex vivo verteporfin concentration and each of BF, BV, and PS.
  
  
  CONCLUSIONS
  The efficacy of verteporfin delivery in tumors is estimated by perfusion CT, providing a noninvasive method of mapping photosensitizer dose.
authors: Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755-8000. Electronic address: Jonathan.T.Elliott@dartmouth.edu.
authors: Jonathan T
authors: JT
authors: Elliott
authors: Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755-8000; Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire.
authors: Kimberley S
authors: KS
authors: Samkoe
authors: Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755-8000.
authors: Jason R
authors: JR
authors: Gunn
authors: Department of Medical Biophysics, Western University, London, Ontario, Canada.
authors: Errol E
authors: EE
authors: Stewart
authors: Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire.
authors: Timothy B
authors: TB
authors: Gardner
authors: Department of Biomedical Engineering, Illinois Institute of Technology, Chicago, Illinois.
authors: Kenneth M
authors: KM
authors: Tichauer
authors: Department of Medical Biophysics, Western University, London, Ontario, Canada.
authors: Ting-Yim
authors: TY
authors: Lee
authors: Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755-8000; Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire.
authors: P Jack
authors: PJ
authors: Hoopes
authors: Institute for Liver and Digestive Health, University College London, London, United Kingdom.
authors: Stephen P
authors: SP
authors: Pereira
authors: Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts.
authors: Tayyaba
authors: T
authors: Hasan
authors: Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755-8000; Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire.
authors: Brian W
authors: BW
authors: Pogue
mesh_terms: D000818:Animals; D003287:Contrast Media; D004195:Disease Models, Animal; D007472:Iohexol; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D017319:Photosensitizing Agents / Q000493:pharmacokinetics*; D010865:Pilot Projects; D011166:Porphyrins / Q000493:pharmacokinetics*; D011817:Rabbits; D014057:Tomography, X-Ray Computed / Q000379:methods*; D000077362:Verteporfin
chemical_list: D003287:Contrast Media; D017319:Photosensitizing Agents; D011166:Porphyrins; D000077362:Verteporfin; D007472:Iohexol
keywords: CT perfusion; Pancreatic cancer; dosimetry; drug delivery; pharmacokinetics; photodynamic therapy