RADIOLABELING OF LIPIODOL WITH GENERATOR-PRODUCED RE-188 FOR HEPATIC TUMOR-THERAPY

In this study we prepared and analyzed the biodistribution of Re-188-l abelled Lipiodol ([Re-188]-Lipiodol) in rats after intrahepatic arteri al injection. EDTB was synthesized by condensation of 1,2-benzenediami ne and ethylenediaminetetraacetic acid (EDTA). The labelling efficienc y of[Re-188] Lipiodol was determined to be greater than 97% by ITLC de veloped with n-hexane. Following incubation of the [Re-188] Lipiodol w ith an equal volume of serum at 37 degrees C for 48 h, ITLC indicated good in vitro stability. Approximately 7.4 MBq [Re-188] Lipiodol was i njected in each rat via the hepatic artery and samples of liver, splee n, muscle, lung, kidney, bone, whole blood and testis were obtained. [ Re-188] Lipiodol tissue concentrations showed that after 1 h intrahepa tic injection most of the radiotracer was retained in the liver, and w as eliminated slowly with a biological half-life of 33.5 h. Radioactiv ity levels in the lung, kidney and blood were moderate at 1 h, and dec lined rapidly over time. In the spleen, muscle, testis and bone, radia tion levels were insignificant. These initial results indicate that [R e-188] Lipiodol may be a potential radiopharmaceutical agent for the t reatment of liver tumors.