Research Article

Tumor-Shed Antigen Affects Antibody Tumor Targeting: Comparison of Two 89Zr-Labeled Antibodies Directed against Shed or Nonshed Antigens

Figure 6

Autoradiography analysis of 89Zr-mAbs depicted as normalized intensity versus normalized length profiles: 89Zr-amatuximab (2.96 MBq) was coinjected with (a) 10 µg and (b) 60 µg amatuximab. 89Zr-B3 (2.22 MBq) was coinjected with (c) 15 µg and (d) 60 µg B3. The results demonstrate that the normalized radioactivity of 89Zr-amatuximab at the tumor core and the periphery was similar with the low dose of amatuximab but the relative 89Zr intensity at the tumor periphery was higher as the injection dose was increased to 60 µg. In contrast, the radioactivity profile of 89Zr-B3 was not affected by the B3 dose between 15 and 60 µg B3 and the radioactivity preferentially accumulated in the tumor periphery.