MRS of 2-hydroxyglutarate (2HG) has the great potential for determining the isocitrate dehydrogenase (IDH) mutational status in brain tumors noninvasively. This clinical role of 2HG MRS may be demonstrated most clearly in patients with brainstem gliomas or deep brain lesions, where surgical biopsy presents significant risk of permanent neurological deficit. We report 2HG MRS data in patients with brainstem tumors. 2HG was evaluated, using a 2HG-optimized TE 97ms PRESS at 3T, in 12 subjects with brainstem lesions in vivo. We also presents data of monitoring the tumor with serial 2HG MRS scans.