18F-Fluorothymidine-Pet Imaging of Glioblastoma Multiforme: Effects of Radiation Therapy on Radiotracer Uptake and Molecular Biomarker Patterns

Introduction. PET imaging is a useful clinical tool for studying tumor progression and treatment effects. Conventional 18F-FDG-PET imaging is of limited usefulness for imaging Glioblastoma Multiforme (GBM) due to high levels of glucose uptake by normal brain and the resultant signal-to-noise intensi...

Full description

Saved in:
Bibliographic Details
Main Authors: Sanjay Chandrasekaran, Andrew Hollander, Xiangsheng Xu, Joseph L. Benci, James J. Davis, Jay F. Dorsey, Gary Kao
Format: Article
Language:English
Published: Wiley 2013-01-01
Series:The Scientific World Journal
Online Access:http://dx.doi.org/10.1155/2013/796029
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Introduction. PET imaging is a useful clinical tool for studying tumor progression and treatment effects. Conventional 18F-FDG-PET imaging is of limited usefulness for imaging Glioblastoma Multiforme (GBM) due to high levels of glucose uptake by normal brain and the resultant signal-to-noise intensity. 18F-Fluorothymidine (FLT) in contrast has shown promise for imaging GBM, as thymidine is taken up preferentially by proliferating cells. These studies were undertaken to investigate the effectiveness of 18F-FLT-PET in a GBM mouse model, especially after radiation therapy (RT), and its correlation with useful biomarkers, including proliferation and DNA damage. Methods. Nude/athymic mice with human GBM orthografts were assessed by microPET imaging with 18F-FDG and 18F-FLT. Patterns of tumor PET imaging were then compared to immunohistochemistry and immunofluorescence for markers of proliferation (Ki-67), DNA damage and repair (γH2AX), hypoxia (HIF-1α), and angiogenesis (VEGF). Results. We confirmed that 18F-FLT-PET uptake is limited in healthy mice but enhanced in the intracranial tumors. Our data further demonstrate that 18F-FLT-PET imaging usefully reflects the inhibition of tumor by RT and correlates with changes in biomarker expression. Conclusions. 18F-FLT-PET imaging is a promising tumor imaging modality for GBM, including assessing RT effects and biologically relevant biomarkers.
ISSN:1537-744X