Purpose: Considering the high prevalence of glioma tumors and the limitation of approaches for assessing response to radiotherapy (RT), or chemo-RT (CRT), the aim of this study was to evaluate the use of quantitative magnetic resonance imaging methods along with the RANO criteria for patient follow-up.
Methods: Seventy-five patients with all types of glioma cell tumors including glioblastoma, oligodendroglia, ependymoma, and astrocytoma with definitive pathologic results were included in this prospective study. Contrast-enhanced lesion volume (CELV), non-enhanced lesion volume (NELV), necrotic tumor volume (NTV), and quantitative values of apparent diffusion coefficient (ADC) and magnetic resonance spectroscopy metabolites (Cho/Cr, Cho/NAA, NAA/Cr) was calculated by a neuroradiologist using a semi-automatic method. All patients were followed up and these values were recalculated one and six months after RT-CRT treatment.
Results: The results of the study showed statistically significant changes before and six months after RT-CRT for M-CELV in all glioma types (p<0.05). In all glioma cell types, the change in M-ADC, M-Cho/Cr, and Cho/NAA indices was incremental, and M-NAA/Cr decreased at six months. A significant difference was observed between diffusion indices changes, and metabolic ratios, and CELV changes in six months in all types (p<0.05). DWI/ADC indices had a higher mean percentage of sensitivity (98.25%) and specificity (96.57%).
Conclusion: The results of the present study showed that ADC and MRS indices can complement the commonly used methods to evaluate the response to CRT treatment of all types of glioma cells, although ADC has more sensitivity and specificity.