Concentration of 99mTc-Sn-N-pyridoxyl-5-methyltryptophan, a biliary agent, in distant metastases of hepatomas.

During the last 2 years, eight patients with hepatocellular carcinoma who were suspected of having distant metastases have been studied to determine whether a new biliary agent, 99mTc-Sn-N-pyridoxyl-5-methyltryptophan (99mTc-PMT), is taken up by extrahepatic tumors. In all eight patients, scintigrams showed a clearly increased uptake of 99mTc-PMT radioactivity by the extrahepatic tumors. In contrast, an increased uptake by the tumors of gallium citrate Ga 67 was only detected in four of the seven patients examined. The results obtained in this study suggest that 99mTc-PMT is useful both for characterizing the nature of extrahepatic tumors in patients with hepatoma and for detecting the metastases.