Figure 4.

(A) Visualization of the pretargeting based on tetrazine. (B–E) Pretargeted imaging of CC49-TCO injected 72 h before the effector molecule in mice bearing LS174T tumor xenograft. (B) Conventional imaging of ¹¹¹In-label CC49 after 1 h, low uptake is observed in the tumor; (C) SPECT/CT images with [¹¹¹In]1 22 h after Tz imaging agent injection. High tumor uptake is observed. KGaA, Weinheim [6,75]. (D) PET/CT image with [⁶⁴Cu]4 in mice bearing the LS174T tumor xenograft. High tumor uptake is observed [75]. (E) PET/CT image with [¹⁸F]25 in mice bearing the LS174T tumor xenograft. High tumor uptake is already observed one hour after injection. Reprinted/adapted with permission from [76]. Copyright © 2021, American Chemical Society.