ABSTRACT of the funded parent grant Because tumor cells can survive chemo/radiation therapies through DNA repairment mediated by poly(ADP- ribose) polymerase-1 (PARP-1). PARP-1 inhibitors (PARPis) alone, or in combination with chemotherapy or radiation therapy, have led to substantial gains in the overall survival of cancer patients, by obstructing PARP- catalyzed single DNA repair. With multiple ongoing clinical trials using PARPis to treat glioma, to quantify baseline PARP expression levels through quantitative PARP PET imaging will provide prognostic information to guide future precision treatment. However, none of the current PARP imaging agents under development is brain penetrant, making reliable in vivo quantification of PARP-1 in the brain challenging. Herein, we propose to evaluate several BBB penetrant PARP-1 inhibitors as potential PET imaging agents.