SLC Transporter-Mediated Functional Imaging in Cancer Diagnosis

Functional imaging has become an important approach for evaluating tumor physiology in vivo beyond morphologic assessment. Radiotracers used for cancer imaging are designed to mimic endogenous substrates or substrate analogues, and their accumulation can depend on membrane transport, intracellular metabolism, and clearance from normal tissues. Specifically, SLC transporters contribute to tracer uptake and signal formation, linking transporter activity with measurable imaging signals in cancer. While [¹⁸F]FDG PET/CT remains the most widely used example of transporter-associated metabolic imaging, SLC transporter-mediated imaging strategies have been developed to assess amino acid transport, sodium-dependent glucose uptake, redox metabolism, lactate exchange, nucleoside metabolism, choline metabolism, and iodide accumulation. Herein, we provide an overview of current applications of SLC transporter-mediated functional imaging in cancer diagnosis, with an emphasis on glucose and amino acid systems. Special attention is given to the relationship between transporter physiology, tracer uptake, tumor type, and diagnostic application.