Fig. 1

Predictive value of 18F-FAZA PET/CT in EAC xenografts. (a) Transverse slices at the level of the hind legs with mice in prone position. PET/CT acquired 3 h after tracer injection. Left: ¹⁸F-FAZA PET images with subcutaneous EAC tumors delineated spherically (orange). Middle: corresponding CT images. Right: Overlay ¹⁸F-FAZA PET/CT. The PET data exterior to the ROI’s was erased. Orange = ROI > 40% isocontour. High ¹⁸F-FAZA uptake was also seen in the urinary bladder due to renal excretion of the tracer. (b) Pre-treatment ¹⁸F-FAZA uptake of RT treated tumors. Regr = tumors that regressed (radiosensitive), Growth = tumors that continued growing (radioresistant). T/B ratios (single values, mean, SD, t-test). (c) Control (Ctrl); Radiotherapy (RT); Combination (RT+). Hypoxia status was defined by ¹⁸F-FAZA PET/CT: T/B < 3.59 = normoxic; T/B ≥ 3.59 = hypoxic. RTG of EAC xenografts (single values, mean, SD, t-test)