PARP1 and neoplasm: We evaluated a novel radiotracer, <sup>18</sup>F-FluorThanatrace ([<sup>18</sup>F]-FTT), to noninvasively assess PARP activity with PET/CT before treatment and determine associations between uptake, tumor mutation status, and prior receipt of therapy including PARP inhibitors.<h4>Methods</h4>Fifty-two patients with solid tumors underwent whole-body (skull base to thigh) [<sup>18</sup>F]-FTT PET/CT scans before beginning PARP inhibitor treatment.