Distribution of 67Ga-citrate in tumor tissues and various organs--macroautoradiographic and scintigraphic studies.

Localization of 67Ga in various tissues was demonstrated by whole-body autoradiography of tumor-bearing mice in order to obtain comprehensive information which would aid in making more accurate interpretations of clinical scintigrams. The macroautoradiograms (ARG's) showed the most intense accumulation of 67Ga in the reticuloendothelial tissues, the wall of the intestinal tract and tumor tissues. 67Ga nonspecifically accumulated in the abdominal region and was apparently excreted mostly from the kidneys and from the mucosa of the intestinal tract. In the reticuloendothelial system such as bone marrow, liver and lymph nodes were sometimes difficult to distinguish from the lung tumor. In the 67Ga-scintigram the high uptake of 67Ga was seen in these organs. Tumor in the lung could be readily detected as the alveolar structure is occupied with a considerable amount of air and has much lower activity per unit volume in the normal lung tissue. Thus the application of 67Ga in autoradiography in experimental animals provided useful information which should assist in analyzation of routine 67Ga-scintigrams in patients with neoplastic diseases.