SIRT1 and central nervous system cancer: PET/CT/MR imaging with 2-[18F]BzAHA for monitoring the pharmacologic inhibition of SIRT1 expression–activity in intracerebral 9L gliomas in rats.Treatment of rats (N = 3) with a single dose of EX-527 (5 mg/kg, i.p., 30 min prior to injection of 2-[18F]BzAHA) resulted in the inhibition of SIRT1 activity in 9L tumors, as evidenced by statistically significant decreases in SUV (P < .005) and DV (P < .005) of 2-[18F]BzAHA as compared to baseline levels (Figure 3; Supplementary Figure S2).