Liver tumor model with implanted rhabdomyosarcoma in rats: MR imaging, microangiography, and histopathologic analysis

• Published in: Radiology Vol. 239; no. 2; p. 554
• Main Authors: Chen, Feng, Sun, Xihe, De Keyzer, Frederik, Yu, Jie, Peeters, Ronald, Coudyzer, Walter, Vandecaveye, Vincent, Landuyt, Willy, Bosmans, Hilde, Van Hecke, Paul, Marchal, Guy, Ni, Yicheng
• Format: Journal Article
• Language: English
• Published: United States 01.05.2006
• Subjects: Angiography; Animals; Disease Models, Animal; Liver Neoplasms - diagnosis; Liver Neoplasms - pathology; Magnetic Resonance Imaging; Male; Neoplasm Transplantation; Rats; Rhabdomyosarcoma - diagnosis; Rhabdomyosarcoma - pathology
• ISSN: 0033-8419
• DOI: 10.1148/radiol.2392050277

In compliance with institutional regulations for care and use of laboratory animals, the aim of this study was to establish and characterize a rodent liver tumor model to provide a platform for preclinical assessment of new diagnostic and therapeutic strategies. A rhabdomyosarcoma tumor was implanted in the right and left liver lobes of 20 rats, for a total of 40 tumors. T1- and T2-weighted magnetic resonance (MR) images, diffusion-weighted images, and dynamic susceptibility contrast agent-enhanced perfusion-weighted images were obtained up to 16 days after tumor implantation and were compared with postmortem three-dimensional computed tomographic (CT) images, digital microangiograms, and histopathologic findings. Fifteen tumors were examined with proton ((1)H) MR spectroscopy. All tumors grew, with a mean volume doubling time of 2.2 days +/- 0.9 (standard deviation) and a final size of 591 mm(3)+/- 124. The rhabdomyosarcoma tumor showed hypervascularity at MR imaging, three-dimensional CT, microangiography, and histologic analysis. On dynamic susceptibility contrast-enhanced perfusion-weighted images, the maximum signal intensity decrease differed in time and extent between the tumor and the liver, with a significantly (P < .001) higher relative blood volume, relative blood flow, and permeability value in the tumor than in the liver. With (1)H MR spectroscopy, the rhabdomyosarcoma tumor and the liver featured significant (P < .001) choline and lipid peaks, respectively. Implantation of a rhabdomyosarcoma tumor in the livers of rats is feasible and reproducible, and this animal model seems promising for future testing of new diagnostic and therapeutic strategies.