CSF1R and neoplasm: PET imaging in non-tumor-bearing mice revealed low blood pool levels of [89Zr]Zr-DFO-N-suc-CSF1R-mAb with SUVmean of 0.3 ± 0.04 at 24 h and 0.2 ± 0.04 at 72 h after injection (Figures 2A, B).