Predicting grade of cerebral gliomas using Myo-inositol/Creatine ratio

Abstract

Purpose

Our aim was to determine the diagnostic accuracy of MI/Cr ratio in determining the grade of glioma.

Materials and methods

Twenty-two patients (14 males and 8 females), ranging in age from 15–63 years (mean 34.4 years) were prospectively recruited for this study. All had a brain tumor recently diagnosed by MRI and had received no previous treatment, except for steroids. They were referred for MRS examination before surgical biopsy and/or resection or radiotherapy. Ratios for MI/Cr, Cho/Cr, and Cho/NAA were obtained for each lesion and compared with the grade of the lesion.

Results

The levels of MI/Cr were higher (2.14 ± 1.4) in patients with low-grade astrocytoma, and lower in patients with anaplastic astrocytoma (0.39 ± 0.11) and GBM (0.025 ± 0.06). 21 out of the 22 patients were correctly classified using MI/Cr ratio, one patient was misdiagnosed as high grade glioma and the biopsy revealed grade II glioma. The diagnostic accuracy, sensitivity and specificity of MI/Cr ratio for the grading of glioma was 95.4%, 100%, and 92.8%, respectively.

Conclusion

MRS has proven to be an important complementary tool saving the patient from unnecessary biopsy taking when it is conclusive thus altering the treatment planning. This study had demonstrated that MI level and MI/Cr ratio are important in presurgical grading of brain tumors.