Effect of a single injection of bevacizumab on tumor vasculature and FDG uptake. Parameters were obtained pretreatment and after one bevacizumab infusion. (a–c) Blood perfusion (a), blood volume (b) and permeability–surface area product (PS; c). Significant decreases after treatment are indicated by solid lines (P < 0.05 by t-test). Blood flow and blood volume decreased significantly in four of the patients. (d) Microvascular density. All patients showed significant decreases after treatment (P < 0.05 by t-test). (e) Fraction of vessels with pericyte coverage. The difference in the fraction of vessels positive for α-smooth muscle actin (α-SMA) in patient 2 was identified as an outlier by the Extreme Studentized Deviate test. Paired t-test analyses of the mean values that included and excluded the data of patient 2 had P < 0.09 and 0.001, respectively. (f) Mean tumor IFP decreased significantly after bevacizumab (P < 0.01 by paired t-test). (g) Tumor FDG uptake before treatment, on day 12 and presurgery (day 93), normalized for muscle values. On day 12 after bevacizumab treatment, a 40% decrease was observed in patient 3, and no change in the other patients. Lower levels were found in all patients before surgery except for patient 5, who had low levels throughout the treatment. In comparison to pretreatment and day 12 values, the median standard uptake value was significantly lower on day 93 (P < 0.01; Supplementary Table 1). (h) Circulating progenitor/stem cells (AC133+; left) and viable CECs (right) in peripheral blood. Samples were run to acquire 50,000 events in the mononuclear/lymphocyte gate. For both cell populations, bevacizumab induced a significant decrease in mean values (P < 0.05 by Wilcoxon signed-rank test). Key in b applies to a,c, g–i.