Studies on Ga-67 citrate uptake in various experimental tumors

Ga-67 citrate uptake was autoradiographically studied in Ehrlich's tumor and sarcoma 180 in mice and 3'-Me-DAB hepatoma in rats with a histological comparison. In order to evaluate the relationship between tumor growth and degree of Ga-67 citrate uptake, animals were sacrificed 3, 5, 7 and 10 days after transplantation of tumor cells of Ehrlich's tumor and sarcoma 180. The results were as follows. 1) When Ga-67 citrate was administered to mice having Ehrlich's tumor, sarcoma 180 and to rats having 3'-Me-DAB hepatoma, varying degrees of accumulation of Ga-67 were seen in all experimental tumors. 2) In Ehrlich's tumor and sarcoma 180, RI uptake ratio (Tumor/Normal tissue uptake ratio; T/N ratio) was increased in accordance with tumor growth and was about 5 in these tumors 10 days after transplantation of tumor cells. On the other hand, RI uptake ratio (Tumor/Normal Liver tissue uptake ratio; T/NL ratio) ranged from 1.62 to 3.31 in 3'-Me-DAB hepatoma. 3) In all tumors, remarkable accumulation of Ga-67 was demonstrated in the highly cellular sites of tumors without degeneration and necrosis. 4) In Ehrlich's tumor and sarcoma 180, an accumulation of Ga-67 citrate was also observed in granulation tissues consisting of fibroblasts, fibrocyte, neutrophils and a small number of lymphocytes around the tumor, and it was more intense than that of tumorous tissue in many cases. 5) In 3'-Me-DAB hepatoma, Ga-67 uptake was seen in hepatocellular carcinoma with little fibrous stroma, but not in cholangiocarcinoma with dense fibrous stroma. (author)