Monitoring multidrug resistance P-glycoprotein drug transport activity with single-photon emission computed tomography and positron emission tomography radiopharmaceuticals

Abstract

Multidrug resistance (MDR) mediated by overexpression of MDR1 P-glycoprotein (Pgp) is one of the best characterized transporter-mediated barriers to successful chemotherapy in cancer patients and there is an expanding requirement to noninvasively interrogate Pgp transport activity in vivo. Both small organic medicinals as well as coordination compounds characterized as transport substrates for MDR1 Pgp are amenable to incorporation of positron emission tomography or single-photon emission computed tomography radionuclides and may enable noninvasive diagnostic imaging of MDR in cancer patients. In particular, several clinically approved [99mTc] complexes already show promise for the functional evaluation of MDR1 Pgp-mediated transport activity in human tumors in vivo. © Springer-Verlag Berlin Heidelberg 2005.