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

Figure 3

Representative PET images of ⁸⁹Zr-mAb in nude mice with A431/H9 tumor: (a) ⁸⁹Zr-amatuximab (2.96 MBq) coinjected with 10 µg and 60 µg amatuximab; (b) ⁸⁹Zr-B3 (2.22 MBq) coinjected with 15 µg and 60 µg B3. Fifteen-minute static PET scans were performed at 3, 24, and 48 h p.i. PET images demonstrate that (a) the tumor uptake significantly increased when the injection dose of ⁸⁹Zr-amatuximab was 60 µg compared with 10 µg dose and (b) there was no significant dose effect on the tumor uptake of ⁸⁹Zr-B3 and the tumor uptake gradually increased over time.

(a)

(b)

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