SCDT-45. ANTIBODY-BASED PET IMAGING OF BRAIN CANCER CELLS INFILTRATION

• Published in: Neuro-oncology (Charlottesville, Va.) Va.), 2017-11, Vol.19 (suppl_6), p.vi274-vi274
• Main Authors: Charest, Gabriel, Sarrhini, Otman, Fortin, David, Stanimirovic, Danica, Gabathuler, Reinhard, Guérin, Brigitte
• Format: Article
• Language: English
• Subjects: Abstracts
• ISSN: 1522-8517; 1523-5866
• DOI: 10.1093/neuonc/nox168.1125

Infiltrated glioblastoma (GBM) cells into the brain parenchyma cause recurrences after tumor resection and there is presently no efficient non-invasive method to detect these infiltrated cells. One obstacle is the blood-brain barrier (BBB), which limits the passage of specific radiolabeled antibodies targeting infiltrated cells to the central nervous system, preventing imaging by positron emission tomography (PET). We hereby aimed to conceive bi-specific radiolabeled antibodies acting in two chronological steps: 1- targeting a transporter to allow receptor-mediated transcytosis through the BBB and 2- targeting a specific biomarker of GBM cells for a specific retention and imaging. We will present the first part of the project consisting to demonstrate that the mono-specific radiolabeled antibody targeting BBB-transporter can actively cross the BBB of healthy rat following injection in the right external carotid artery. This method allows for high tracer concentration in the right hemisphere after first passage following the injection. Comparing the specific radiolabeled antibody to a non-specific antibody, we observe that only the BBB-transmigrating antibody is momentary retained at the BBB and then returns in the blood circulation. We will next assess whether this transitory uptake to the BBB is sufficient to let the bi-specific antibody reaches and link a specific antigen present on the migrating GBM cells. This study demonstrates that our radiolabeled antibody allows for a transitory and specific uptake to the BBB. These successful results are promising for the use of bi-specific radiolabeled antibody targeting infiltrated GBM cells thus should enabling for specific PET imaging.