FIGURE 5. Composite of posterior images of 2 nude mice bearing human prostate tumor DU145. Twenty days earlier, mouse at left was given 12.6 MBq (340 µCi) ¹¹¹In-oxine and mouse on right was given 16.7 MBq (450 µCi) ¹¹¹In-Merc. Images show that >90% of ¹¹¹In is still in tumor (intense white spot). In either case, tumor size had not increased. At sacrifice, 93% of ¹¹¹In was still associated with tumor, 2% was in kidneys, and 2% in liver. Remaining 2% was in carcass. Total amount of ¹¹¹In (corrected to decay) remaining in mice was 85% ± 3% of activity injected. Dose received by these tumors was estimated to be 32 Gy (3,200 rad) and 42 Gy (4,200 rad), respectively. (Note that because of low resolution of gamma camera, it appears in these images that ¹¹¹In is homogeneously spread in tumor, including that in necrotic portion of tumor. In autoradiographs, Fig. 3, better resolution is achieved and absence of ¹¹¹In in necrotic area is visible.).