Fig. 3

Intravital fluorescence microscopy (IVFM) enables longitudinal monitoring of orthotopic BxPC3 tumors in vivo. Top row (a) shows representative fluorescence images of non-irradiated BxPC3 tumors in one mouse. Bottom row (b) shows representative fluorescence images of BxPC3 tumors treated with 5 × 8 Gy SBRT in another mouse. BxPC3 cells (DsRed) are shown in red and tumor cell HIF activity (5xHRE/GFP) in green. White arrows indicate regions of BxPC3 tumor cell HIF activity. In vivo labeling of tumor microvasculature was performed by intravenous injection of APC-conjugated CD31 antibody (cyan). Scale bar = 500 μm.