Preoperative Determination of Isocitrate Dehydrogenase Mutation in Gliomas Using Spectral Editing MRS: A Prospective Study

Background The edited magnetic resonance spectroscopy (MRS) technique has not yet been formally evaluated for the in vivo detection of 2‐hydroxyglutarate (2‐HG) in patients with gliomas of various grades. Purpose To evaluate the diagnostic accuracy of edited MRS in the preoperative identification of the isocitrate dehydrogenase (IDH) mutation status in patients with gliomas. Study Type Prospective. Population Fifty‐eight subjects (31 glioblastomas, 27 grade II and III gliomas). Field Strength/Sequence Mescher–Garwood (MEGA)‐PRESS and routine clinical brain tumor MR sequences were used at 3T. Assessment Data were analyzed using an advanced method for accurate, robust, and efficient spectral fitting (AMARES) from jMRUI software. The amplitudes of the 2‐HG, N‐acetyl‐aspartate (NAA), choline (Cho), and creatine/phosphocreatine (Cr) resonances were calculated with their associated Cramer–Rao lower bound (CRLB). The IDH1 R132H mutation status was assessed by immunohistochemistry for all patients. Patients with grades II and III gliomas with negative immunohistochemistry underwent DNA sequencing to further interrogate IDH mutation status. Statistical Test The differences in 2‐HG amplitudes, 2‐HG/NAA, 2‐HG/Cho, and 2‐HG/Cr between IDH‐mutant and IDH‐wildtype gliomas were assessed using Mann–Whitney U‐tests. Receiver operating characteristic curve analysis was performed to evaluate the diagnostic accuracy of each parameter. Results The 2‐HG amplitudes, 2‐HG/NAA, and 2‐HG/Cho were higher for IDH‐mutant gliomas than IDH‐wildtype gliomas (P