Prevention of hepatic metastases by intravenous radioactive gold.

This investigationwas designedto determinewhether livertumorgrowthcan be preventedby localizedradioac tivfty through radioactive gold (198Au) infusion. Colloidal 198Auis phagocytosedby Kupifercells and emits I@-and a-radiation. Measurementof a-radiation showedmarked 198Auliver concentration. Liver chemistries, histology, and isolated hepatocyte function studies that measure [14C]acetateincorporationinto bile acid and cholesterol formationafter doses from 200 to 3000gtCiwere serially determined.A 4OO-@zCi dose(2944rads)providedsubstan tial local radiationin the liver for 9 days withouttoxicity. Three hundredtwenty-sevenmale 150-gSprague-Dawley rats received either stable (“cold―) colloidalgold, 198Au, intraportallyor through a peripheral vein within 10 mm following intraportal infusion of 10,000,000 Walker 256 sarcoma cells. In 66 other rats intraportal 198Auadminis trationwas delayedfor 2 weeks after tumorimplantation. In rat livers that received †̃98Au early following tumor injection, significantly fewer tumors were observed than in controls(p < 109). When radiationwas delayed for 2 weeks after tumor infusion,the differenceswere not as significant. Intraportal or systemic 198Augiven within 10 mm follow ing tumor infusion can protect an animal from hepatic tumor growth without significant liver toxicity. That he patic radiation may prevent tumor growth may have im portant clinical implications.