Correlation between Magnetic Resonance Spectroscopy and Perfusion at Non-enhancing Edematous Area and Tumor Recurrence in High-grade Gliomas after Maximal Safe Resection

Background: On neuroimaging in patients with high-grade glioma, the non-enhancing edematous area (NEA) is usually wider than the enhancing edematous area (EA). Objective: To study the correlation between magnetic resonance spectrometry (MRS), perfusion MRI (MRP) parameters in the NEA and recurrent time of high-grade gliomas. Material and Method: Sixty-two patients with high-grade gliomas underwent MRS and MRP before maximal safe resection. Choline (Cho), creatine (Cr), N-acetyl-aspartate (NAA), lactate, lipid (Lip), ratio of Cho/Cr and Cho/NAA and relative cerebral blood volume (rCBV) were collected from the NEA. Progression free survival and recurrent time after appropriate therapy were correlated with metabolic profiles and perfusion study. Results: The majority of patients (93.5%) had peritumoral edema with various degree of edema. Mean recurrent time of glioblastoma was 5.9 months. To compare three parameters of MRS (Cho/NAA, Cho/Cr, rCBV) of the EA and NEA, there was statistical difference, but Cho/NAA and rCBV were not statistically significant for predicting recurrent time of the tumors. Conclusion: Recurrent time depends on the presence of peritumoral edema resulting from infiltrative area of tumor in NEA demonstrated by high Cho/NAA, Cho/Cr and rCBV. The metabolic parameter (Cho/NAA) and perfusion MRI (rCBV) was not beneficial to determine recurrent time in patients with high-grade glioma. Keywords: High-grade glioma, Non-enhancing edematous area, Proton magnetic resonance spectroscopy, Magnetic resonance perfusion