Experimental research of 99Tcm-MIBI SPECT in detecting multidrug resistance status on tumor nude mice

Objective: To analyze 99Tcm-MIBI images separately before and after VPL in nude mice bearing human lung tumors in order to find a feasible way in evaluating MDR status of tumor with 99Tcm-MIBI image. Methods: Analysis of 99Tcm-MIBI images was performed at 15 min, 60 min and 120 min after injecting 99Tcm-MIBI 7.4 MBq in female BALB/c nude mice bearing human lung tumors. The tumor uptake rate (TUR) and retention rate (RI) were calculated and the data were analyzed. P-gp albumen ex-pression was determined by flow cytometry. Results: Significance difference in TUR was observed for at the 15th, 60th or 120th min between the imaging in the control group versus in the second imaging in VPL reverse group as well as between the first imaging and the second imaging in the reverse group. Furthermore, there was negative correlation between retention rate (RI) and P-gp albumen expression. Conclusion: These results for the first time demonstrate that the results of 99Tcm-MIBI imaging exhibits a negative correlation to P-gp albumen expression, indicating that analysis of 99Tcm-MIBI imaging may be a potential indicator for MDR status of tumor and can be used to monitoring the role of VPL in reverting the multidrug resistance. (authors)