[Scintigraphic visualization of Pgp protein: a non-invasive method to evaluate the MDR cellular character]

The MDR character is a major factor that influence the effectiveness of cancer chemotherapy. This feature can be noninvasively evaluated through 99mTc isonitrils (MIBI, Tetrofosmin) scintigraphy, because these radiotracers cellular efflux is mediated by the Pgp membranar active transport system, the same that mediate chemotherapy drugs cellular efflux. The Pgp glycoprotein overexpression in the case of the MDR positive tumoral cells will determine both the chemotherapic drug and the isonitrile radiotracer quickly efflux from the cell. This paper present, based both on the literature and personal authors research work, the principle of the method, radiotracers structural characteristics and cellular uptake mechanism, practical protocol details from the acquisition untill the qualitative and quantitative image processing and results interpretation. Quantification indexes are proposed for the radiotracer cellular uptake quantitative evaluation on the scintigraphic image. The results could bring the possibility to make MDR positive patient diagnosis and further selection for the MDR modulators drug therapy.