title: A Dual Tracer 18F-FCH/18F-FDG PET Imaging of an Orthotopic Brain Tumor Xenograft Model.
abstract: Early diagnosis of low grade glioma has been a challenge to clinicians. Positron Emission Tomography (PET) using 18F-FDG as a radio-tracer has limited utility in this area because of the high background in normal brain tissue. Other radiotracers such as 18F-Fluorocholine (18F-FCH) could provide better contrast between tumor and normal brain tissue but with high incidence of false positives. In this study, the potential application of a dual tracer 18F-FCH/18F-FDG-PET is investigated in order to improve the sensitivity of PET imaging for low grade glioma diagnosis based on a mouse orthotopic xenograft model. BALB/c nude mice with and without orthotopic glioma xenografts from U87 MG-luc2 glioma cell line are used for the study. The animals are subjected to 18F-FCH and 18F-FDG PET imaging, and images acquired from two separate scans are superimposed for analysis. The 18F-FCH counts are subtracted from the merged images to identify the tumor. Micro-CT, bioluminescence imaging (BLI), histology and measurement of the tumor diameter are also conducted for comparison. Results show that there is a significant contrast in 18F-FCH uptake between tumor and normal brain tissue (2.65 ± 0.98), but with a high false positive rate of 28.6%. The difficulty of identifying the tumor by 18F-FDG only is also proved in this study. All the tumors can be detected based on the dual tracer technique of 18F-FCH/18F-FDG-PET imaging in this study, while the false-positive caused by 18F-FCH can be eliminated. Dual tracer 18F-FCH/18F-FDG PET imaging has the potential to improve the visualization of low grade glioma. 18F-FCH delineates tumor areas and the tumor can be identified by subtracting the 18F-FCH counts. The sensitivity was over 95%. Further studies are required to evaluate the possibility of applying this technique in clinical trials.
authors: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore.
authors: Yilong
authors: Y
authors: Fu
authors: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore.
authors: Lai-Chun
authors: LC
authors: Ong
authors: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore.|Department of Chemical Engineering, Siddaganga Institute of Technology, B.H. Road, Tumkur-572103, India.
authors: Sudhir H
authors: SH
authors: Ranganath
authors: SingHealth Experimental Medicine Center, Singapore General Hospital, Block 9, Level 3, Outram Road, Singapore 169608, Singapore.
authors: Lin
authors: L
authors: Zheng
authors: SingHealth Experimental Medicine Center, Singapore General Hospital, Block 9, Level 3, Outram Road, Singapore 169608, Singapore.
authors: Irene
authors: I
authors: Kee
authors: NUS Environmental Research Institute, National University of Singapore, 1 Create Way, Create Tower #15-02, Singapore 138602, Singapore.
authors: Wenbo
authors: W
authors: Zhan
authors: National Cancer Centre, 11 Hospital Drive, Singapore 169610, Singapore.
authors: Sidney
authors: S
authors: Yu
authors: National Cancer Centre, 11 Hospital Drive, Singapore 169610, Singapore.|Office of Clinical Sciences, Duke-NUS Graduate Medical School, Singapore, 169857, Singapore.
authors: Pierce K H
authors: PK
authors: Chow
authors: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore.
authors: Chi-Hwa
authors: CH
authors: Wang
mesh_terms: D000818:Animals; D001932:Brain Neoplasms / Q000000981:diagnostic imaging*; D045744:Cell Line, Tumor; D002794:Choline / Q000031:analogs & derivatives*; D004195:Disease Models, Animal; D019788:Fluorodeoxyglucose F18; D005909:Glioblastoma / Q000000981:diagnostic imaging; D064593:Heterografts; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008163:Luminescent Measurements / Q000379:methods; D051379:Mice; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C514960:fluorocholine; D002794:Choline