Sequential uptake patterns of technetium-99m pyrophosphate in hepatoma.

Sequential liver scintiphotography with Tc-99m pyrophosphate (PYP) was used to prospectively evaluate its uptake patterns in hepatoma. The scintiphotos and time-activity curves of 40 cases were analyzed. Two distinct patterns of tumor activity were noted: gradual but complete extraction and trapping of Tc-99m PYP in hepatoma in 38% of the patients (group 1), and absence of subsequent Tc-99m PYP uptake in hepatoma after initial blood pool activity in 62% of the patients (group 2). Since extraction and trapping of Tc-99m PYP occur approximately in two fifths of the patients with hepatoma, we conclude that Tc-99m PYP liver scintigraphy is not worthwhile supplementing the conventional radionuclide studies for diagnosing hepatoma, even in the selected patients in the countries where the prevalence of hepatoma is high.