Scintigraphic detection of multidrug resistance in cancer.

One of the most extensively studied mechanisms of drug resistance involves the drug efflux pump P-glycoprotein (Pgp). The availability of radiolabeled substrates of Pgp such as 99mTc-MIBI and analogous 99mTc-labeled agents allows the clinical assessment of Pgp function in cancer patients. The consistency of the results from different institutions and trials strongly support the clinical application of this imaging technique for individual tailoring of chemotherapeutic regimens and for designing clinical trials with Pgp modulators.