The importance of 1H MRS examination in the assessment of peritumor infiltration in patients with cerebral glioma

Determination of the borders of the tumors plays crucial role to planning adequate therapy and enables prognosis. Diagnostic imaging methods do not allow to evaluate the boundaries of the infiltrate precisely. In this study we try to evaluate metabolite ratios in 1HMRS spectra to assess tumor spreading in border zone and to determine diagnostic values these parameters in predicting follow up. The objective of the study was to assess the usefulness of 1HMRS in the evaluation of the extent of the infiltrate around the apparently unchanged tumor area. The study group consisted of 64 patients with cerebral glioma. In all patients MR and single-voxel MR spectroscopy were performed. MRS spectra were obtained from the solid part of the tumor and from the VOI's placed in the borders of the tumor. The analysis of the metabolite ratios in the groups of patients with recurrent malignant lesions and in patients without signs of recurrent lesions revealed statistically significant differences for Lip/Cr and Lac/Cr ratios in the consequent voxels in peritumoral zone. Our results indicate that analyse of the spectra and metabolite ratios in uncertain zone enables to depict neoplasmatical infiltration in morphologically unchanged tissue. The demonstration of metabolic changes in the uncertain zone can be potentially used for the selection of an appropriate operative treatment and radiotherapy because of ability to discriminate the group of patients with a higher risk of a recurrent lesion. [author]