Plasma clearance of Tc-99(m)-MAG3: Accuracy of five single-sample methods

The aim of this study was to compare the accuracy of five single-injection, single-sample methods for the assessment of plasma clearance of Tc-99(m)-M AG3 in adults. In 51 patients, a reference plasma clearance was determined on the basis of 16 blood samples. It ranged from 13 to 313 ml.min(-1). In p atients with a plasma clearance less than 75 ml.min(-1), there was a large difference between the clearance obtained by a single-sample method and the reference method. Thus single-sample methods should not be used with these patients. In patients with a plasma clearance higher than 75 ml.min(-1), t he relative difference was (mean +/- s): 6.07 +/- 9.96% (Russell et al., 19 89), 14.22 +/- 8.08% (Muller-Suur et al., 1991), 7.29 +/- 6.21% (Bubeck et al., 1992), 6.64 +/- 7.71% (Russell et al., 1996) and 17.39 +/- 7.39% (Pier a et al., 1997). Reference clearance was overestimated by all five single-s ample methods, especially by the methods of Muller-Suur et al. and Piera et al. The smallest standard deviation was obtained using the method of Bubec k et al. This method is recommended for use in patients with a plasma clear ance greater than 75 ml.min(-1). ((C) 2000 Lippincott Williams & Wilkins).