title: In vivo18F-fluorodeoxyglucose-positron emission tomography/computed tomography imaging of pancreatic tumors in a transgenic rat model carrying the humanKRASG12Voncogene.
abstract: A novelKRAS-mediated transgenic rat model has previously been demonstrated, in which animals develop multiple pancreatic ductal adenocarcinoma (PDAC) that is histologically similar to human PDAC within two weeks. Positron emission tomography (PET)/computed tomography (CT) is commonly used for the diagnosis and staging of PDAC in humans, and can be adopted for optimal use in animal experiments. The aim of the present study was to evaluate the carcinogenic process in a rat pancreatic carcinoma model using small-animal multimodality imaging systems. The utility of fluorodeoxyglucose (FDG)-PET/CT in detecting the location and size of PDAC during tumor development in the present transgenic rat model was assessed. A small animal multimodality PET/CT system and contrast-enhanced CT (CECT) system were used for the imaging analysis ofKRASG12Vmale transgenic rats (n=6), which developed pancreatic tumors following the administration of an injection of Cre recombinase (Cre)-carrying adenovirus. Laparotomies performed at six weeks post-treatment revealed that all three (100%) Cre-expressing rats developed pancreatic tumors that were <2 mm in diameter, none of which were detected by18F-FDG PET/CT or CECT. At eight weeks post-treatment, the pancreatic tumors were heterogeneously visualized by18F-FDG-PET/CT and CECT in two of the three rats. Furthermore, the autopsies confirmed that all three rats had developed pancreatic tumors. These novel findings provide evidence that the FDG-PET/CT imaging system is a valuable tool for the evaluation of the carcinogenic process, and one which may aid in treatment and preventive methods for pancreatic tumors in mammalian models. A limitation associated with the early detection of PDACs warrants further investigation.
authors.affiliation: Department of Molecular Toxicology, Nagoya City University Graduate School of Medical Sciences and Medical School, Nagoya, Aichi 467-8601, Japan ; Division of Surgical Oncology, Department of Surgery, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Shibata
authors.affiliation: Department of Molecular Toxicology, Nagoya City University Graduate School of Medical Sciences and Medical School, Nagoya, Aichi 467-8601, Japan.
authors.forename: Katsumi
authors.initials: K
authors.lastname: Fukamachi
authors.affiliation: Diagnostic Imaging Program, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Chiba 263-8555, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tsuji
authors.affiliation: Diagnostic Imaging Program, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Chiba 263-8555, Japan.
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Saga
authors.affiliation: Department of Molecular Toxicology, Nagoya City University Graduate School of Medical Sciences and Medical School, Nagoya, Aichi 467-8601, Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Futakuchi
authors.affiliation: Division of Surgical Oncology, Department of Surgery, Nagoya University Graduate School of Medicine, Nagoya, Aichi 466-8550, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Nagino
authors.affiliation: Laboratory of Nanotoxicology Project, Nagoya University, Nagoya, Aichi 467-8603, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tsuda
authors.affiliation: Department of Molecular Toxicology, Nagoya City University Graduate School of Medical Sciences and Medical School, Nagoya, Aichi 467-8601, Japan.
authors.forename: Masumi
authors.initials: M
authors.lastname: Suzui
keywords: 18F-fluorodeoxyglucose; carcinogenesis; laparotomy; pancreatic tumor; positron emission tomography/computed tomography; rat model