Pharmacokinetic model of myocardial (99m)Tc-sestamibi washout.

Abstract

OBJECTIVES:

Technetium-99m sestamibi ((99m)Tc-MIBI) scintigraphy has been reported to be a functional imaging tool for in vivo detection of mitochondrial dysfunction in myocardium and multidrug resistance-associated protein expression in tumors. The purpose of this study was to propose a clinically applicable pharmacokinetic model with metabolic equilibrium of (99m)Tc-MIBI and to evaluate the accuracy of the model.

METHODS:

For this study, eight healthy men received (99m)Tc-MIBI scintigraphy. The planar images were obtained at 0.25, 0.5, 1, 2, 3, 4, 5, and 6 h after (99m)Tc-MIBI injection. The measured time series (99m)Tc-MIBI counts were fitted to our model by nonlinear regression analysis. The predictive performance of the model was determined by comparing the residuals between measured and predicted values.

RESULTS:

We obtained a good regression by fitting data from 0.25 to 6 h after (99m)Tc-MIBI injection, with excellent correlation between measured and predicted (99m)Tc-MIBI counts (R(2) = 0.9792) and a slope near unity. The 95% confidence interval of the mean prediction error included 0, which means that the prediction was not significantly biased. The precision of the prediction was also excellent.

CONCLUSIONS:

Our model shows good predictive capacity, with favorable bias and accuracy. By comparing the predictive values of this model with measured values, mitochondrial (99m)Tc-MIBI washout can be quantified. (99m)Tc-MIBI washout rates are reported to be a promising method for evaluating cardiac function in patients with cardiac diseases and P-glycoprotein expression in tumor cells. Therefore, this quantification could be useful for mitochondrial functional imaging, especially in patients with cardiac diseases or tumors.

• Authors: Tsubasa Watanabe, Hajime Monzen, Masatake Hara, Takashi Mizowaki, Masahiro Hiraoka
• Journal: Annals of nuclear medicine (Ann Nucl Med) Vol. 27 Issue 3 Pg. 279-84 (Apr 2013) ISSN: 1864-6433 [Electronic] Japan
• PMID: 23344692 (Publication Type: Clinical Trial, Journal Article)

Chemical References

• Technetium Tc 99m Sestamibi

Topics

• Adult
• Humans
• Male
• Models, Biological
• Myocardium (metabolism)
• Reproducibility of Results
• Technetium Tc 99m Sestamibi (pharmacokinetics)