IDH1 and brain neoplasm: S5). A slower washout of [18F]AG-120 from the IDH1R132H tumor compared to the IDH1 tumor results in a slightly higher activity concentration at later time points (30–60 min p.i.), resulting in AUC0–60 min values of 9.96 and 8.65 SUV*min, respectively (Fig. 8). However, the interpretation of the data is complicated by a potential non-specific accumulation of activity in the brain tumors of animals due to impairment of the BBB, which is indicated by a contrast enhancement of the tumors after i.v. injection of the contrast agent Gadovist® (Fig. S12b).