Visualisation of Neuroblastoma Growth in a Scid Mouse Model Using [¹⁸F]FDG and [¹⁸F]FLT-PET

Abstract

Background: Tumor therapy has been monitored using the metabolic indicator [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG). However, the nucleotide precursor [¹⁸F]fluoro-thymidine ([¹⁸F]FLT) is in principle more specific as it is incorporated into DNA. Thus, the [¹⁸F]FDG and [¹⁸F]FLT uptake by human neuroblastomas grown in Scid mice are compared in this study. Materials and Methods: Scid mice were inoculated with human neuroblastoma cells. Tumor imaging was performed with a human whole-body full-ring PET scanner. Furthermore, the tumor weight and the cell proliferation rate were determined. Results: Neuroblastomas could be visualised using [¹⁸F]FDG in 40% and with [¹⁸F]FLT in 70% of the cases. [¹⁸F]FDG or [¹⁸F]FLT uptake could not be visualised in neuroblastomas less than 1.0 g in weight. No correlation between the cell proliferation rate and tracer uptake could be detected. Conclusion: [¹⁸F]FLT showed a higher uptake than [¹⁸F]FDG and, therefore, might be more suitable for monitoring anticancer therapy, at least in this tumor model.