A new technique for labeling of Lipiodol with 188Re in the treatment of hepatic tumor

A new method for the synthesis of Re-188-Lipiodol without using a chelating agent and to evaluate the stability and biodistribution of the new agent in rats with hepatic tumors was attempted. Eighteen male Sprague-Dawley rats with liver tumors were sacrificed at 1, 24, and 48 hours (six rats at each time) after injection of approximately 7.4 MBq (0.2 mCi) of Re-188 Lipiodol via the hepatic artery. Samples of tumor, liver and other organs were collected and tissue concentration (%ID/g) of the markers were calculated. Our data showed a high level of radioactivity in the hepatic tumors at every time of the study. The ratios of tumor to normal liver tissue concentration (T/N ratio) were 7.62 at 1 hour, 8.03 at 24 hours, and 7.70 at 48 hours. Except for the liver, kidneys and lungs, concentrations in other organs were low. The new method for labeling Lipiodol with Re-188 is simple and has potential for the treatment of hepatic tumors.