Definition

A radioconjugate composed of the melanocyte-stimulating hormone receptor (MSHR; melanocortin-1 receptor; MC1R; melanin-activating peptide receptor; melanotropin receptor)-targeting moiety, VMT02, labeled with the radioisotope gallium Ga 68, with potential imaging activity using positron emission tomography (PET). Upon administration of gallium Ga 68-VMT02, VMT02 targets and binds to MC1R-expressing tumor cells. Upon PET imaging, MC1R-expressing tumor cells can be detected. MC1R, a G protein-coupled receptor expressed by melanocytes that binds to melanocortins, is involved in regulating mammalian skin and hair color. It is upregulated on the surface of metastatic melanoma cells.