Definition

A radioconjugate composed of a nanobody directed against human epidermal growth factor receptor 2 (HER2; EGFR2; ERBB2) that is labeled with technetium Tc 99m, with potential use as a tracer for HER2-expressing tumors using single photon emission computed tomography/computed tomography (SPECT/CT). Upon administration of technetium Tc-99m-MIRC208, the anti-HER2 nanobody moiety targets and binds to HER2-expressing tumor cells. This facilitates both the detection of HER2-expressing tumor cells and the assessment of responses to HER2-targeting chemotherapeutic agents using SPECT/CT. HER2, a receptor tyrosine kinase, is overexpressed on the cell surfaces of various tumor cell types; it plays a key role in tumor cell proliferation and tumor vascularization.