Figure 5.
SPECT/CT imaging of [123I]KX1 with ex-vivo corresponding autoradiography and tissue histology. (A) SPECT/CT image of an OVCAR8 tumor bearing mouse showed elevated uptake in the tumor compared to surrounding tissue, the white arrow corresponds to the tumor. (B) Ex-vivo autoradiography of tumor vs. muscle showed greater uptake in the tumor. (C) Using three separate measures of tumor to muscle ratios we found differences in instrument sensitivity corresponded to better delineation of tumor uptake compared to normal tissues with the highest tumor to muscle uptake ratio obtained from autoradiography. (D) Ex-vivo histology of tumors after imaging showed tumors were positive for DNA damage marker RPA and muscles showed less. There was a tumor-dependent uptake of the radiotracer that corresponded to higher DNA damage. Untreated control tumors showed reduced RPA staining compared to treated tumors. These data provide the proof of concept for this approach and translate our in-vitro findings in-vivo.