Serial FDG-PET imaging results in HCT116 ( K - ras ) tumors at early times after treatment with RO5126766, 0.3 mg/kg. (a) Coronal PET images from one mouse presenting vehicle - (upper panel) and RO5126766 treated group on days 1, 2 and 3 of treatment. Tumors are shown in the boxed area, twofold magnification. (b) Comparison of changes in [18 F]FDG uptake from baseline to day 1, day 2 and day 3 of treatment, presented as% change SUVmax value to baseline (*p < 0.05; **p < 0.01). The SUVmax values are mean + SE (n = 5).