[¹⁸F]FDG and [¹⁸F]FLT PET-CT and MR Imaging of Human Neuroblastomas in a SCID Mouse Xenograft Model

Abstract

Background: Finding new therapeutic agents is of great clinical interest in neuroblastoma research because prognosis of children with disseminated stages of disease is still poor. As xenograft mouse models are frequently used for studying anticancer drugs in vivo, small animal imaging is an important method of monitoring in anticancer research. Materials and Methods: SCID mice inoculated with human neuroblastoma SK-N-SH cells were examined with positron-emission tomography-computed tomography (PET-CT) using [¹⁸F]fluorodeoxyglucose (FDG) or [¹⁸F]fluoro-L-thymidine (FLT) and with magnetic resonance imaging (MRI). Results: All neuroblastomas were detected by MRI. In PET-CT imaging, no tumour was visualized with [¹⁸F]FDG, but 13 out of 14 (93%) were found with [¹⁸F]FLT. Uptake of [¹⁸F]FLT was significantly associated with tumour weight. Necrotic areas could not be identified either by MR imaging or on PET-CT scans. Conclusion: Both MR and PET-CT imaging with [¹⁸F]FLT are highly qualified for the detection of neuroblastomas grown in SCID mice. However, [¹⁸F]FDG, which is the standard tracer in clinical PET-CT imaging, is not suited for PET-CT imaging in the neuroblastoma model.