Background: Conventional models for prediction of survival in patients with primary biliary cirrhosis (PBC) are based on the results of blood tests and on the clinical condition, which may be affected by treatment. We evaluated the usefulness of hepatic receptor imaging with [99mtechnetium]-diethylenetriaminepentaacetic acid galactosyl human serum albumin (GSA) for the staging and prognosis of PBC without the need for reference to laboratory test results.
Methods: The subjects were 45 patients with PBC, 10 healthy subjects, 62 patients with chronic hepatitis and 144 patients with cirrhosis. Computer acquisition of gamma-camera data was started just before the injection of 185 MBq [99mTc]-GSA and was stopped 20 min later. Time-activity curves were generated from regions of interest (ROI) for the heart and liver. A receptor index was calculated by dividing the radioactivity of the liver ROI by that of the liver-plus-heart ROI 15 min after the injection. An index of blood clearance was calculated by dividing the radioactivity of the heart ROI 15 min after the injection by that of the heart ROI 3 min after the injection.
Results: The median receptor index was higher in patients with PBC than in those with cirrhosis. Among patients with PBC, the receptor index was lower in those with stage IV disease than in those in stages I, II or III. The index of blood clearance was lower in patients with PBC than in those with cirrhosis. Among patients with PBC, the index of blood clearance was higher in those with stage IV disease than in those in stages I, II or III. The receptor index was correlated significantly both to the risk score of the Mayo model and to the prognostic index of the Japanese model. The index of blood clearance was also correlated significantly to this score and prognostic index.
Conclusions: Hepatic receptor imaging with [99mTc]-GSA is useful for the evaluation of hepatic functional reserve, staging of PBC and assessment of prognosis.