99mTc-tetrofosmin for functional imaging of P-glycoprotein modulation in vivo

Tetrofosmin is a widely available and conveniently prepared tracer that has been shown to be a transport substrate for Pgp and MRP in vitro and in vivo. Its properties are similar but not identical to those of sestamibi. The available data suggest that clinical studies involving imaging of MDR function and in vivo modulation of MDR function could be performed with tetrofosmin or sestamibi, but the two should probably not be used interchangeably.