Quantitative Correlation at the Molecular Level of Tumor Response to Docetaxel by Multimodal Diffusion-Weighted Magnetic Resonance Imaging and [ 18 F]FDG/[ 18 F]FLT Positron Emission Tomography

• Published in: Molecular imaging Vol. 14; no. 1; p. 7290201400045
• Main Authors: Honndorf, Valerie S, Schmidt, Holger, Wehrl, Hans F, Wiehr, Stefan, Ehrlichmann, Walter, Quintanilla-Martinez, Leticia, Barjat, Hervé, Ricketts, Sally-Ann, Pichler, Bernd J
• Format: Journal Article
• Language: English
• Published: United States 01.01.2015
• ISSN: 1536-0121

We aimed to quantitatively characterize the treatment effects of docetaxel in the HCT116 xenograft mouse model, applying diffusion-weighted magnetic resonance imaging (MRI) and positron emission tomography (PET) using 2-deoxy-2-[ F]fluoro-D-glucose ([ F]FDG) and 3'-deoxy-3'-[ F]-fluorothymidine ([ F]FLT). Mice were imaged at four time points over 8 days. Docetaxel (15 mg/kg) was administered after a baseline scan. Voxel-wise scatterplots of PET and apparent diffusion coefficient (ADC) data of tumor volumes were evaluated with a threshold cluster analysis and compared to histology (GLUT1, GLUT3, Ki67, activated caspase 3a). Compared to the extensive tumor growth observed in the vehicle-treated group (from 0.32 ± 0.21 cm to 0.69 ± 0.40 cm ), the administration of docetaxel led to tumor growth stasis (from 0.32 ± 0.20 cm to 0.45 ± 0.23 cm ). The [ F]FDG/ADC cluster analysis and the evaluation of peak histogram values revealed a significant treatment effect matching histology as opposed to [ F]FLT/ADC. [ F]FLT uptake and the Ki67 index were not in good agreement. Our voxel-based cluster analysis uncovered treatment effects not seen in the separate inspection of PET and MRI data and may be used as an independent analysis tool. [ F]FLT/ADC cluster analysis could still point out the treatment effect; however, [ F]FDG/ADC reflected the histology findings in higher agreement.