Differences between glioblastomas and primary central nervous system lymphomas in 1H-magnetic resonance spectroscopy

Abstract

Abstract:Purpose: The present study aimed to distinguish between glioblastomas and primary central nervous system lymphomas (PCNSLs) using 1 H-Magnetic Resonance Spectroscopy (MRS), especially glutamate (Glu) / creatine (Cr) and Glu/Glu + glutamine (Gln) ratios.Materials and methods: A total of 46 patients (31 cases diagnosed with glioblastoma, 15with PCNSL) were examined by in vivo single-voxel proton 1 H-MRS with a 3-T MR imaging system. Differences in absolute concentration of Cr, choline/Cr, lipid (1.3ppm)/Cr, Glu+Gln/Cr, Glu /Cr, and Glu/Glu+Gln ratios among groups were evaluated with Mann-Whitney U test.Results: PCNSLs (3.408 ± 1.194 [standard deviation]) showed significantly higher Glu/Cr ratios as compared to glioblastomas (2.220 ± 0.942; P= 0.003) (Glu/Cr cutoff ratio of 2.509showed a sensitivity of 88% (7/8) and a specificity of 92% (22/24)), while glioblastomas (0.539 ± 0.098) showed significantly lower Glu/Glu+Gln ratios as compared to PCNSLs (0.728 ± 0.147; P<0.001) (Glu/Glu+Gln cutoff ratio of 0.558 showed a sensitivity of 69%(18/26) and a specificity of 100% (13/13)). And PCNSLs (1.101 ± 0.387) showed significantly higher Cho/Cr ratios as compared to glioblastomas (0.850 ± 0.465; P= 0.026). Conclusion:Glu/Cr, Glu/Glu+Gln, and Cho/Cr ratios may be useful in distinguishing (Figure 1d, 1e). The independent quantification of Glu and Gln can be considerably improved by moving from 1.5T to 3T.With regard to Glu+Gln, it has been reported that Glu+Gln/Cr ratios from contrast-enhancing regions do not differ significantly between glioblastomas and PCNSLs [2]. No differences inGlu or Gln alone in in vivo 1 H-MRS between them have been reported, to the extent that we could determine.On the other hand, it has been reported that in high-grade gliomas (World HealthOrganization grades III and IV), microdialysates in the tumor periphery consistently show significantly higher extracellular Glu relative to microdialysates in non-tumoral regions, unlike PCNSL [5]. And, high extracellular Glu has been noted to stimulate Gln synthetase and promote the synthesis of Gln from Glu in cultured astrocytes [6].Based on these reports, we hypothesized that in glioblastomas due to high extracellular Glu the synthesis of Gln from Glu would be promoted [6], and so Glu/Glu+Gln ratios might be lower than those in PCNSLs. The purpose of this study was to analyze the differences in the 1 H-MRS findings among glioblastomas and PCNSLs with special reference to Glu and Gln expression. Materials and Methods:Patients:This retrospective analysis of the data was approved by the institutional review board of our university. All patients gave informed consent prior to inclusion in this study. All patients Clinical parameters in the analyzed groups are summarized in Table 1. All tumors were confirmed histopathologically after preoperative diagnosis with magnetic resonance imaging (MRI) and 1 H-MRS, and were not subjected to biopsy, surgical resection, chemotherapy or radiation therapy before the preoperative diagnosis with MRI and 1 H-MRS. We...

MRI as a diagnostic biomarker for differentiating primary central nervous system lymphoma from glioblastoma: A systematic review and meta‐analysis

“…Detailed information of excluded studies is described in the Supplementary Materials. One further relevant study was also identified, resulting in a final total of 22 studies investigating the diagnostic performance of MRI for differentiating PCNSL from glioblastoma, with these studies covering 1182 patients.…”

“…Seven studies enrolled patients in a consecutive manner, while the enrollment was not explicit in the others. Nineteen studies used only histopathology as the reference standard, while two studies used histopathology and clinicoradiologic diagnosis for patients with PCNSL …”

“…A variety of MRI sequences were used in various combinations (Table ), with the most commonly used sequences being DWI in 14 studies, DSC in nine studies, and DCE in four studies . The other less‐commonly used sequences were ASL in four studies, SWI in four studies, MRS in three studies, and IVIM in two studies . In terms of the ROI placement, the entire enhancing tumor was selected in 14 studies, and both the entire enhancing tumor and peritumoral area were selected in seven studies .…”

“…During the last decade, multiple MRI sequences have been introduced for differentiating PCNSL from glioblastoma . These sequences, which include diffusion‐weighted imaging (DWI), dynamic susceptibility‐weighted contrast‐enhanced imaging (DSC), dynamic contrast‐enhanced imaging (DCE), arterial spin labeling (ASL), susceptibility‐weighted imaging (SWI), intravoxel incoherent motion (IVIM), and magnetic resonance spectroscopy (MRS), have demonstrated variable diagnostic performance.…”

Diagnostic Accuracy of T1-Weighted Dynamic Contrast-Enhanced–MRI and DWI-ADC for Differentiation of Glioblastoma and Primary CNS Lymphoma

“…Fourth, due to the lack of routine use of magnetic resonance spectroscopy (MRS) in this retrospective study, we were unable to evaluate the utility of MRS, which has been shown to distinguish PCNSL from GBM, and in one study, with a specificity exceeding 90%. 43 The added value of MRS in discriminating the diagnoses should be incorporated in future prospective studies. Fifth, the manual drawing and transfer of VOIs to parametric maps could have introduced variability.…”