Study of Distribution of ¹⁶⁹Yb, ⁶⁷Ga and ¹¹¹In in Tumor Tissue by Macroautoradiography

—Comparison between viable tumor tissue and necrotic tumor tissue—

Abstract

The localization of ¹⁶⁹Yb, ⁶⁷Ga and ¹¹¹In in tumor tissues was determined macroauto-radiographically. ¹⁶⁹Yb-citrate, ⁶⁷Ga-citrate and ¹¹¹In-citrate were injected intravenously to the rats subcutaneously transplanted Yoshida sarcoma and were injected intraperitoneally to the mice subcutaneously transplanted Ehrlich tumor. These animals were sacrificed 3, 24 and 48 hours after injection. These tumor tissues were frozen in n-hexane (-70°C) cooled with dry ice-acetone. After this, these frozen tumor tissues were cut into serial thin sections (10μm) in the cryostat (-20°C) . One of the slice of these sections was then placed on X-ray film and this film was developed after exposure of several days. On the other hand, next slice of these sections were then stained using the hematoxylin and eosin. From the observations of these autoradiogram and H·E stained slice, the following results were obtained.
Concentration of ¹⁶⁹Yb, ⁶⁷Ga and ¹¹¹In was predominant in viable tumor tissue rather than in necrotic tumor tissue, regardless of time after the administration. ⁶⁷Ga and ¹¹¹In were distributed uniformly in viable tumor tissue, but deposition of ¹⁶⁹Yb was observed more avidly in viabl tumor tissue neighboring to necrotic tumor.