ITGAM and neoplasm: In conclusion, [<sup>64</sup>Cu]-Cu-αCD11b Db is a high-affinity and stable diabody, which can quantify CD11b-positive TAMCs in the tumor microenvironment, particularly when the molar activity of the administered [<sup>64</sup>Cu]-Cu-αCD11b Db is optimized for managing the CD11b antigen sink in the spleen, liver, and bone marrow.