Tumor and liver uptake models of 67Ga-citrate.

After administration 67Ga concentrates with time in lysosomes from the cytoplasm of liver cells. The lysosomal role in the accumulation of 67Ga in the liver cell is weakened upon transformation of the liver cell into a malignant tumor cell. In malignant tumors (except for hepatoma) the lysosome does not play a major role in the tumor concentration of 67Ga. 67Ga is bound to acid mucopolysaccharides (keratan polysulfate, etc.) in both tumor and liver. In liver cells, large amounts of 67Ga are transported into lysosomes with these acid mucopolysaccharides, and in hepatoma cells, quite large amounts of 67Ga are transported into lysosomes with these acid mucopolysaccharides. In malignant tumor cells (except for hepatoma) the effect is much smaller, the acid mucopolysaccharides transporting very little 67Ga into lysosome. The 67Ga is concentrated in viable tumor tissue within malignant tissue but hardly at all in necrotic tumor tissue, and concentrates avidly in inflammatory infiltration around tumor cells. Plenty of 67Ga is found in liver but very little in connective tissue associated with the liver.