Figure 7.

Microscopic and DAR images of histological sections of PC-3 and TZM-bl tumors of both xenograft models: In the H&E images, obvious necrotic areas (black arrow) were observable in the tumors from the mouse model. In the subsequent IHC sections, [⁸⁹Zr]Zr-DFO-HSA accumulation was clearly visible at the same locations (brown color precipitate, black arrows). The areas stained in the IHC correspond to the regions with strong radioactivity enrichment in the DAR (coded in red). Similar areas were not noted in the tumors of the CAM model, having a more homogeneous distribution of zirconium-89 activity and HSA. In general, IHC could verify the accumulation of [⁸⁹Zr]Zr-DFO-HSA due to the EPR effect.