MRS And PWI Applied Research In Brain Metastasis

一、Application of MRS and PWI in diagnosis of brain metastasisObjective:Analyze the relationship between tumor volume and Cho/Cr, tumor volume and rCBV, Cho/Cr and rCBV. Explore the application value of MRS and PWI in the diagnosis of brain metastasis.Methods:Collect56lesions (NSCLC43, breast cancer13) of47patients of untreated brain metastasis (NSCLC37, breast cancer13) from May2010to October2012in the hospital. All lesions were scanned by cMRI and MRS, and16of which were(NSCLC11, breast cancer5) also scanned by PWI. Measure 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×lengthxwidth×height). Process MRS and PWI data using Functool software, select the maximum tumor Cho/Cr, measur and calculat normalized rCBV ratios (rCBVnor=rCBV within the tumor/average rCBV in the contralateral normal appearing white matter). Analyze the Cho/Cr and normalized rCBV between two different sources of metastasis by t-test of two independent samples, and examine the correlation between each two of Cho/Cr, normalized rCBV, and tumor volume using the Pearson correlation test analysis.Results:MRS and PWI data of brain metastasis derived from NSCLC and breast cancer were statistically analyzed results as follows:1. Cho/Cr and normalized rCBV were not statistically different (P=0.971,0.932);2. The correlation between Cho/Cr and tumor volume has statistical significance (Pearson correlation coefficient=0.369, P=0.005), but no correlation between normalized rCBV and tumor volume (Pearson correlation coefficient=0.443,P=0.085);3. Cho/Cr and normalized rCBV was highly correlated (Pearson correlation coefficient=0.884, P<0.001).Conclusions:The positive correlations exist between tumor volume and Cho/Cr, Cho/Cr and rCBV in brain metastasis. MRS and PWI could reflect the tumor cell metabolism and angiogenesis, the combination of the two along with cMRI could improve and complete diagnosis of brain metastasis further.二、MRS-based GKS treatment efficacy analysis of brain metastasis Objective:Assess the efficacy of GKS by detecting the metabolite levels changes of brain metastasis before and after treatment by MRS, thereby exploring the application value of MRS in the interim efficacy of GKS treatment follow-up.Methods:Collect24lesions from21brain metastasis patients treated with GKS or confirmed by clinical (NSCLC10, breast cancer2, ovarian cancer2, renal cell carcinoma2, the primary lesion of unknown5) between August2011and December2012in the Gamma Knife Center of our hospital. Target lesions were all performed cMRI and MRS within24hours before the GKS treatment,1month and4months after treatment. Calculate the tumor volume, achieve the levels of the NAA, Cr, Cho, LL, NAA/Cr, Cho/Cr, NAA/Cho and Cho/NAA with post-processing software and further compute 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) manually. Analyze the tumor parenchyma nNAA, nCr, nCho, nLL and NAA/Cr, Cho/Cr, NAA/Cho, Cho/NAA ratio before the GKS treatment,1month and4months after treatment applying ANOVA, and perform Kruskal-Wilcoxon and Wilcoxon rank sum test on tumor volume change.Results:1.The changes of tumor nCho、Cho/Cr、Cho/NAA and Cho/cNAA before the GKS treatment,1month and4months after reatment was statistically significant (P <0.001,P<0.001, P=0.003and P=0.002), but the changes of tumor volume, nCr, nNAA, nLL and NAA/Cr were not statistically significant (P=0.382, P=0.075, P=0.370, P=0.442and P=0.509);2. The changes of Tumor nCho, Cho/Cr, Cho/NAA and Cho/cNAA before and1month after the GKS treatment were statistically significant (P=0.019, P=0.029, P=0.031and0.034), while the rest of the values were not statistically significant;3.The changes of tumor volume, nCho, nCr, Cho/Cr, Cho/NAA and Cho/cNAA before and4months after GKS treatment were statistically significant (P=0.046,P<0.001, P=0.026, P<0.001, P=0.001and P<0.001), the rest was not statistically significant;4. The changes of tumor volume, nCho and Cho/Cr between1month and4months follow-up after GKS treatment were statistically significant (P=0.012, P=0.039and P=0.042).Conclusions:The changes of tumor metabolite levels are earlier than the morphological changes, MRS is able to evaluate early effect of the GKS on brain metastasis; the nCho, Cho/Cr, Cho/NAA and Cho/cNAA value demonstrate their superiorities on brain metastasis GKS efficacy evaluation; cMRI combining with MRS can more accurately determine the GKS efficacy.