| Objective:To observe the variation of the MRS before and after the GKS treatment in patients with malignant brain tumor, to reveal the value of MRS in assessing the early therapeutic effect of GKS.Methods:15 patients with 20 brain metastasis (BM) and 6 patients with Glioma, confirmed by pathology or clinic, were in this study. Conventional MRI and Multivoxel 2D proton spectroscopy scan were performed in all target lesions just before the GKS therapy and 30 days after. We measured the length and the width of the tumor on the axial plane, and the height on the coronal or sagittal plane, and the tumor volume was then calculated according to the Ellipsoid cubature formula (V=π/6×length×width×height). The levels of the NAA, Cr, Cho, NAA/Cr, Cho/Cr, NAA/Cho and Cho/NAA were computed with Functool (GE workstation ADW4.2). The nMetabolite (the ratio of the tumor metabolite level to the corresponding metabolite level of the normal brain) and the Cho/cNAA (cNAA——the level of the contralateral brain) were calculated manually. The changing of the tumor's volume and its MRS parameters were statistically analyzed by PAIRED-SAMPLE T test.Results:1. The change of the volumes varied greatly, the directions and the degrees were different, with no significant difference (P>0.05).2. In the BM group, the ratios of nCho, nNAA, nLL, Cho/Cr, Cho/NAA and Cho/cNAA reduced after the GKS, while the ratios of nCr and NAA/Cr increased. The change of nCho, Cho/Cr, Cho/NAA and Cho/cNAA were statistically significant (P＜0.05), and the change of Cho/NAA and nCho were obviously statistically significant (P＜0.01).3. The trend in the glioma group was similar to the BM group, except for nCr. However, statistical significance was only found in nCho (P＜0.05).Conc l us i ons:MRS revealed that the metabolic changes of the malignant brain tumor after GKS is earlier than the conventional MRI. MRS is important in near therapeutic effect judgment and estimation prognosis diagnosis. |
PDF Full Text Request