Involvement of the glutathione S-conjugate compounds and the MRP protein in Tc-99m-tetrofosmin and Tc-99m-sestamibi uptake in glioma cell lines.

The objective of this study was to compare the accumulation of Tc-99m-tetrofosmin and Tc-99m-sestamibi in four grade IV glioma cell lines and to correlate their accumulation with the multidrug resistance of the cells. Tc-99m-tetrofosmin in all glioma cell lines showed slightly higher uptake and more efficient release beyond 150 min than Tc-99m-sestamibi and the retention of both tracers in the cells was to a certain extend inversely proportional to their degree of multidrug resistance. The results obtained showed that the efflux of both tracers was carried out only in part through the MRP/GS-X pump system. Tc-99m-tetrofosmin showed good potential as a marker of recurrent malignant glioma and in vivo studies are currently underway to confirm these observations.