Tc-99m MIBI liver imaging for hepatocellular carcinoma: correlation with P-glycoprotein-multidrug-resistance gene expression.

Objective: Technetium-99m methoxyisobutyl isonitrile (MIBI) has been shown to be useful in identifying several types of tumors, such as breast, lung and thyroid cancers. There are only a few reports in the literature regarding Tc-99m MIBI uptake in hepatocellular carcinoma, and the results are conflicting. The aim of this study was to investigate the relationship between Tc-99m MIBI accumulation in patients with hepatocellular carcinoma and the gene expression of P-glycoprotein-multidrug-resistance.

Methods: Twenty-two patients with hepatocellular carcinoma were enrolled in this study. Tc-99m MIBI imaging was performed 10 minutes after intravenous injection of 20 mCi Tc-99m MIBI. All patients had liver biopsy or surgery within 1 week of MIBI imaging. Immunohistochemical study of the biopsy or resected hepatocellular carcinoma specimens was performed using the anti-human P-glycoprotein antibody.

Results: On Tc-99m MIBI imaging, 20 of 22 (90.9%) patients with hepatocellular carcinoma showed negative Tc-99m MIBI uptake in tumor lesions, whereas only 2 patients showed positive Tc-99m MIBI uptake in tumor lesions. P-glycoprotein expression was observed in 13 of 20 (65%) patients with negative Tc-99m MIBI uptake, but in the 2 patients who showed positive Tc-99m MIBI uptake in tumor lesions, P-glycoprotein expression was negative.

Conclusions: Tc-99m MIBI SPECT is a useful noninvasive method for predicting the expression of P-glycoprotein-multidrug-resistance gene in hepatocellular carcinoma patients.