¹⁸FDG a PET tumor diagnostic tracer is not a substrate of the ABC transporter P-glycoprotein.

2-[18F]fluoro-2-deoxy-d-glucose (18FDG) is a tumor diagnostic radiotracer of great importance in both diagnosing primary and metastatic tumors and in monitoring the efficacy of the treatment. P-glycoprotein (Pgp) is an active transporter that is often expressed in various malignancies either intrinsically or appears later upon disease progression or in response to chemotherapy. Several authors reported that the accumulation of 18FDG in P-glycoprotein (Pgp) expressing cancer cells (Pgp+) and tumors is different from the accumulation of the tracer in Pgp nonexpressing (Pgp−) ones, therefore we investigated whether 18FDG is a substrate or modulator of Pgp pump.