title: Time-course studies of implanted rabbit VX2 liver tumors to identify the appropriate time for starting hepatic arterial embolization in animal models.
abstract: OBJECTIVE
  We followed the 4-week course of implanted VX2 tumors in rabbits and compared MRI and pathological findings to determine the appropriate time for starting therapy in animal liver tumor models.
  
  
  METHODS
  We used 18 Japanese white rabbits. The VX2 liver tumor was harvested from one tumor-bearing rabbit and implanted in the liver of the other 17 rabbits. They were then sacrificed at 1 (n = 5), 2 (n = 3), 3 (n = 4), and 4 weeks (n = 5) after implantation and MRI study. Using MRI scans and/or pathological specimens of individual rabbits, we evaluated the tumor survival ratio, the major tumor axes, intrahepatic metastases, and peritoneal dissemination.
  
  
  RESULTS
  All tumor transplantations were successful. At 1 week, 56.25% of the implanted tumors were visualized on MRI scans. At 2 weeks or later, all transplanted rabbits were confirmed to be tumor-bearing on MRI scans. At 3 weeks after implantation, the tumor size was similar on MRI scans and in pathological specimens. There were no intra-hepatic metastases or peritoneal disseminations within 2 weeks of tumor transplantation.
  
  
  CONCLUSIONS
  We suggest that in studies of implanted VX2 models addressing the treatment of solid hepatic tumors, it may be prudent to start hepatic arterial embolization at 2 weeks after implantation.
authors.affiliation: Department of Radiology, Shiga University of Medical Science, Otsu, Japan. akinaga@belle.shiga-med.ac.jp
authors.forename: Akinaga
authors.initials: A
authors.lastname: Sonoda
authors.forename: Norihisa
authors.initials: N
authors.lastname: Nitta
authors.forename: Ayumi
authors.initials: A
authors.lastname: Nitta-Seko
authors.forename: Shinichi
authors.initials: S
authors.lastname: Ohta
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Nagatani
authors.forename: Kenichi
authors.initials: K
authors.lastname: Mukaisho
authors.forename: Hideji
authors.initials: H
authors.lastname: Otani
authors.forename: Keiko
authors.initials: K
authors.lastname: Tsuchiya
authors.forename: Masashi
authors.initials: M
authors.lastname: Takahashi
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Murata
mesh_terms: D000818:Animals; D004621:Embolization, Therapeutic / Q000379:methods*; D006499:Hepatic Artery; D008113:Liver Neoplasms / Q000473:pathology* / Q000628:therapy*; D008279:Magnetic Resonance Imaging; D023421:Models, Animal; D009368:Neoplasm Transplantation; D011817:Rabbits; D013997:Time Factors