MR spectroscopy for noninvasive prediction of IDH status in low-grade glioma with 2-hydroxyglutarate integrated with glutamate and glutamine / 中华放射学杂志

ABSTRACT

Objective:To investigate the functional imaging parameters that effectively distinguish isocitrate dehydrogenase (IDH) gene mutation status in clinical practice with long echo time (TE) point-resolved spectroscopy (PRESS) MRS.Methods:Totally 25 patients with suspected diagnosis of low grade gliomas(LGGs; Grade II) were recruited prospectively and divided into IDH mutation group and IDH wild group according to pathological results in the study. All patients were scanned with long TE PRESS MRS. In addition, IDH mutational status was determined by post-operation Sanger sequencing. The t test or Mann-Whitney U test was used to analyze the differences of 2-hydroxyglutarate (2HG), Glutamate (Glu), Glutamine (Gln) and 2HG/Glu+Gln between the IDH mutation group and the IDH wild group, then ROC curve was plotted with statistically significant indexes to obtain the efficacy of predicting IDH mutation status. Results:Of the 25 patients, 19 had IDH mutant gliomas and 6 had IDH wild-type gliomas. 2HG, Glu, Gln and 2HG/Glu+Gln in IDH mutated group were 1.42 (1.09, 1.93)mmol/L, (1.74±1.31)mmol/L, (1.68±0.66)mmol/L, 0.55 (0.28, 0.77), respectively; while the corresponding values were 0.00 (0.00, 1.30)mmol/L, (3.28±1.02)mmol/L, (2.55±1.47)mmol/L, 0.00 (0.00, 0.26) in IDH gene wild type group, respectively. The differences of 2HG, Glu, and 2HG/Glu+Gln between the two groups were statistically significant ( P values were 0.030, 0.016, 0.004, respectively). The area under the ROC curve of 2HG/Glu+Gln was the largest (0.877), and the sensitivity was the highest (84.2%). Conclusion:The integration of 2HG with Glu and Gln can effectively realize the noninvasive assessment of IDH mutation status.