18 kDa translocator protein positron emission tomography facilitates early and robust tumor detection in the immunocompetent SB28 glioblastoma mouse model

• DOI: 10.3389/fmed.2022.992993
• Publication Date: 2022-10-17T04:35:15Z
• Authors: Laura M. Bartos; Sabrina V. Kirchl...; Jens Blobner; Karin Wind; Lea H. Kunze; Adrien Holzgreve; Lukas Gold; Artem Zatcepin; Zeynep Ilgin Kolabas; Selin Ulukaya; Lorraine Weidner; Stefanie Quach; Denise Messerer; Peter Bartenstein; Joerg C. Tonn; Markus J. Riemens...; Sibylle Ziegler; Louisa von Baumga...; Nathalie L. Albert; Matthias Brendel
• Keywords: Translocator protein; Ex vivo; Fluorodeoxyglucose; Standardized uptake value

Introduction The 18 kDa translocator protein (TSPO) receives growing interest as a biomarker in glioblastoma. Mouse models can serve an important tool for the investigation of biomarkers glioblastoma, but several glioblastoma indicated only low TSPO-PET signals contrast to high human Thus, we aimed investigate imaging syngeneic immunocompetent SB28 mouse model, which is thought closely represent tumor microenvironment (TME) Methods Dynamic TSPO-PET/CT was performed 60 min after injection 13.6 ± 4.2 MBq [ F]GE-180. Contrast enhanced CT (ceCT) acquired prior PET and served assessment volumes attenuation correction. sham mice were imaged at early (week-1; n = 6 SB28, sham) late time-point (week-3; 8 9 inoculation. Standard truth ex vivo obtained time-point. Tracer kinetics analyzed lesion site carotid arteries establish image derived input function (IDIF). ceCT compared with by calculation root-mean-square-errors (RMSE). Volumes distribution (VTmax/mean) calculated using IDIF standardized uptake values (SUVmax/mean) 40–60 time frame. Results Higher rate constants (K1) observed week-1 lesions when week-3 lesions. Highest agreement between achieved 50% maximum threshold (RMSE-VT: 39.7%; RMSE-SUV: 34.4%), similar (RMSE: 30.1%). Lesions had higher signal (VTmax 6.6 2.9 vs. 3.9 0.8, p 0.035; SUVmax 2.3 0.5 1.2 0.1, < 0.001) remained level 5.0 1.6 2.7 0.029; 1.9 0.2, 0.0012). VTmax correlated ( R 2 0.532, 0.001). Conclusion facilitates detection over tumors mirror could valuable translational model study TSPO biomarker.