Figure 6.

huAR9.6 can delineate lymph node involvement in a xenograft model of ovarian cancer. A, PET-CT image of a mouse bearing a subcutaneous OVCAR3 xenograft acquired 6 days after the intravenous injection of 2.14 mg/kg [⁸⁹Zr]Zr-DFO-huAR9.6 (250 μCi; 9.25 MBq; 53 μg) showing uptake of radioactivity in the tumor (T), liver (L), and ipsilateral lymph node chain. B, Pan-cytokeratin (pan-CK) IHC staining of the OVCAR3 tumor showing a pattern of CK expression that is characteristic of epithelial cancer cells. C–E, Pan-CK IHC staining of the PET-positive IALN showing (C) immunoreactive foci of neoplastic cells (red arrowheads) and lymphatic fluid (black arrows) in the subcapsular sinuses. D, The cortex of the LN showing CK positivity in star-shaped cells (green arrowheads) indicative of dendritic cells and (E) a cluster of neoplastic cells infiltrating the IALN (red arrows) (E); F, IHC staining of the OVCAR3 tumor with huAR9.6 showing membranous staining of the OVCAR3 cells. G–I, huAR9.6 IHC staining of the PET-positive IALN (G) showing the presence of a few neoplastic cells (red arrowheads). The inset shows the appearance of the huAR9.6-stained PET-positive but H&E-negative IALN, and the red box in the inset identifies the portion shown in the main image. H, The cortex and follicles of the LN showing positivity for huAR9.6 staining in star-shaped cells (yellow arrowheads) indicative of dendritic cells. I, A cluster of neoplastic cells draining into and infiltrating the medulla of the IALN (red arrows). The inset shows the architecture and appearance of the corresponding huAR9.6-stained PET-positive but H&E-negative IALN, and the red box in the inset identifies the portion shown in the main image.