title: Anti-angiogenic therapy affects the relationship between tumor vascular structure and function: A correlation study between micro-computed tomography angiography and dynamic contrast enhanced MRI.
abstract: To compare the effects of two anti-angiogenic drugs, bevacizumab and a cytosolic phospholipase A2-α inhibitor (AVX235), on the relationship between vascular structure and dynamic contrast enhanced (DCE)-MRI measurements in a patient-derived breast cancer xenograft model.
  
  
  
  Mice bearing MAS98.12 tumors were randomized into three groups: bevacizumab-treated (n = 9), AVX235-treated (n = 9), and control (n = 8). DCE-MRI was performed pre- and post-treatment. Median initial area under the concentration-time curve (IAUC60) and volume transfer constant (Ktrans) were computed for each tumor. Tumors were excised for ex vivo micro-CT (computed tomography) angiography, from which the vascular surface area (VSA) and fractional blood volume (FBV) were computed. Spearman correlation coefficients (ρ) were computed to evaluate the associations between the DCE-MRI and micro-CT parameters.
  
  
  
  With the groups pooled, IAUC60and Ktranscorrelated significantly with VSA (ρ = 0.475 and 0.527; P = 0.019 and 0.008). There were no significant correlations within the control group. There were various significant correlations within the treatment groups, but the correlations in the bevacizumab group were of opposite sign, for example, Ktransversus FBV: AVX235, ρ = 0.800 (P = 0.014); bevacizumab, ρ = -0.786 (P = 0.023).
  
  
  
  DCE-MRI measurements can highly depend on vascular structure. The relationship between vascular structure and function changed markedly after anti-angiogenic treatment. Magn Reson Med 78:1513-1522, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
authors.affiliation: Department of Circulation and Medical Imaging, NTNU, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Eugene
authors.identifier: 0000-0003-0066-7051
authors.initials: E
authors.lastname: Kim
authors.affiliation: Department of Circulation and Medical Imaging, NTNU, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Jana
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Tumor Biology, Institute for Cancer Research, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway.
authors.forename: Gunhild Mari
authors.initials: GM
authors.lastname: Maelandsmo
authors.affiliation: Department of Biology, NTNU, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Berit
authors.initials: B
authors.lastname: Johansen
authors.affiliation: Department of Circulation and Medical Imaging, NTNU, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Siver Andreas
authors.initials: SA
authors.lastname: Moestue
mesh_terms: D020533:Angiogenesis Inhibitors / Q000494:pharmacology*; D000818:Animals; D000068258:Bevacizumab / Q000494:pharmacology; D045744:Cell Line, Tumor; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D051379:Mice; D009374:Neoplasms, Experimental / Q000098:blood supply / Q000000981:diagnostic imaging / Q000188:drug therapy; D009389:Neovascularization, Pathologic / Q000000981:diagnostic imaging / Q000188:drug therapy; D055114:X-Ray Microtomography / Q000379:methods*; D023041:Xenograft Model Antitumor Assays
chemical_list: D020533:Angiogenesis Inhibitors; D000068258:Bevacizumab
keywords: DCE-MRI; anti-angiogenic therapy; micro-CT; permeability surface-area product; tumor vasculature