Clinical application of asialoglycoprotein receptor-mediated liver scintigraphy using 99mTc-DTPA-galactosyl-human serum albumin

Technetium-99m-diethylenetriaminepentaacetic acid-galactosyl-human serum albumin (99mTc-GSA) is a new liver scintigraphy agent which binds to asialoglycoprotein receptors on the hepatocytes. Studies were performed in three normal volunteers and 19 patients with chronic liver diseases. Serial scintigrams and time-activity curves of heart and liver were obtained for 60 min following a single intravenous injection of 99mTc-GSA (1 mg/185 MBq). %Injected dose (%ID) in the blood at 60 min after injection and that in the liver were determined. Excellent hepatic images were obtained for 60 min in normal subjects, and neither blood pool image nor extrahepatic uptake was recognized. In the studies of patients, however, blood pools were also visualized in various degrees suggesting altered receptor quantity, although the livers were visualized clearly. The %ID in the blood at 60 min after the injection showed significant correlations with serum albumin levels (r=-0.741, p<0.0001), retention rates of ICG at 15 min (r=0.855, p<0.0001), plasma disappearance rates of ICG (r=-0.760, p<0.0005), prothrombin times (r=-0.696, p<0.002), hepaplastin tests (r=-0.575, p<0.05), total bilirubin levels (r=0.689, p<0.001) and Child Turcotte scores (r=0.769, p<0.0001). Significant differences of %ID in both blood and liver were observed between normal subjects and patients in accordance with severities of the hepatic disorders. These results suggest that 99mTc-GSA liver scintigraphy is useful in evaluating the liver function. (author)