Definition

A radioconjugate comprised of PEG3-FPN, a pegylated tracer for melanin, and labeled with the positron-emitting isotope fluorine F 18, that can be used as a diagnostic imaging agent to detect melanin-expressing cells using positron emission tomography (PET). Upon administration, fluorine F 18-PEG3-FPN targets and binds to melanin-expressing cells. Upon PET, fluorine F 18 can be detected, and melanin-expressing cells can be visualized. Melanin is expressed in many melanomas, and pegylation lowers nonspecific uptake by the liver.