Diagnostic performance of a receptor-binding radiopharmacokinetic model.

Abstract

The aim of this study was to determine which measurement obtained from a radiopharmacokinetic model of a receptor-binding radiotracer provides the highest diagnostic performance for the detection of diffuse hepatocellular disease. Twenty-seven healthy subjects and 46 patients with diffuse hepatocellular disease were studied with the receptor-binding radiopharmaceutical, 99mTc-galactosyl-neoglycoalbumin. A radiopharmacokinetic model was used to produce estimates of receptor concentration [R]o, the scaled forward-binding rate constant Kb, hepatic plasma volume, Vh, extrahepatic plasma volume, Ve and hepatic plasma flow, F. Receiver operating characteristic analysis of each model estimate was conducted. Receptor concentration [R]o and the metrics [R]o/tbw and kb[R]o[R]o/tbw provided the best discrimination between healthy and diseased liver. The forward-binding rate constant kb and the metrics F/Ve and Vh/tbw provided no discrimination. Based on simplicity and higher measurement precision, [R]o was selected as the most accurate index of hepatic function.