[The relationship between 99mTc-MIBI scintimammography of breast cancer and multidrug-resistant proteins].

OBJECTIVE:To evaluate the relationship between the clearance rate of technetium-99m methoxyisobutylisonitrile ((99m)Tc-MIBI) in scintimammography and multidrug-resistant proteins expression in breast cancer tissues. METHODS:Seventy-six patients with breast cancer underwent (99m)Tc-MIBI scintimammography before treatment, and static planar images were taken at 10 min and 180 min after scintimammography. The clearance rate of (99m)Tc-MIBI was calculated in each patient. Immunohistochemical analysis was performed on pathological specimens of the 76 breast tumors to determine the expression of P-glycoprotein (P-gp), glutathione S-transferase Pi (GST-pi) and topoisomerase II (Topo II). RESULTS:The clearance rate was significantly higher in 36 patients with positive P-gp expression when compared with that in 40 patients with negative P-gp expression. There was no significant relationship between GST-pi, Topo II and the clearance rate of (99m)Tc-MIBI. CONCLUSION:The clearance rate of (99m)Tc-MIBI in breast imaging may be used to evaluate the P-gp level in breast cancers.