Figure 2.

General concept of cleavable radioimmunoimaging using click-to-release chemistry in vivo. The TCO-linked and radiolabeled mAb is administered and internalizes in the tumor cells. Once enough tumor internalization has occurred, the trigger (tetrazine) is administered, which can solely react with TCO in blood and in other extracellular compartments given its non-cell-permeable nature. The result of this bioorthogonal reaction is the rapid release of the radiolabeled chelator in circulation and its efficient renal excretion, increasing the T/B ratio. Created with Biorender.com