DIAGNOSTIC PERFORMANCE OF A RECEPTOR-BINDING RADIOPHARMACOKINETIC MODEL

The aim of this study was to determine which measurement obtained from a radiopharmacokinetic model of a receptor-binding radiotracer provid es the highest diagnostic performance for the detection of diffuse hep atocellular disease. Methods: Twenty-seven healthy subjects and 46 pat ients with diffuse hepatocellular disease were studied with the recept or-binding radiopharmaceutical, (99m)-Tc-galactosyl-neoglycoalbumin. A radiopharmacokinetic model was used to produce estimates of receptor concentration [R](o), the scaled forward-binding rate constant k(b), h epatic plasma volume, V-h, extrahepatic plasma volume, V-e and hepatic plasma flow, F. Receiver operating characteristic analysis of each mo del estimate was conducted. Results: Receptor concentration [R](o) and the metrics [R](o)/tbw and k(b)[R](o)[R](o)/tbw provided the best dis crimination between healthy and diseased liver. The forward-binding ra te constant k(b) and the metrics F/V-e and V-h/tbw provided no discrim ination. Conclusion: Based on simplicity and higher measurement precis ion, [R](o) was selected as the most accurate index of hepatic functio n.