Department of Radiology, German Cancer Research Center (dkfz), Heidelberg, Germany.
Invest Radiol. 2010 Dec;45(12):755-68. doi: 10.1097/RLI.0b013e3181ec9db0.
Because of the heterogeneous nature of glioma, biopsies performed should be targeted at the most anaplastic region. Several functional magnetic resonance imaging (MRI) or positron emission tomography (PET) techniques have been proposed for identifying the most anaplastic tumor area. However, it is unclear whether the recommended biopsy targets based on these various functional imaging modalities correspond with each other. Thus, the purpose was to evaluate whether they identify similar target areas.
A total of 61 patients with suspected glioma were assessed within 2.3 +/- 3.5 days by MRI, 18F-fluorothymidine-, and 18F-fluorodeoxyglucose-PET. Thirty-five patients underwent gross total resection and 26 were stereotactically biopsied. MRI was performed on a 1.5 Tesla broadband transmit/receive system, using a double-resonant birdcage coil. The MRI protocol comprised of sodium (23Na)-MRI (3D-radial projection imaging), proton spectroscopic imaging (1H-MRSI, point-resolved spectroscopy), arterial spin-labeling (ASL) perfusion MRI, dynamic contrast-enhanced (DCE) MRI, and dynamic-susceptibility-weighted (DSC) perfusion MRI after a single dose each of gadobenate dimeglumine. Also, apparent diffusion coefficient (ADC) maps were processed from diffusion tensor images. Image analysis comprised a detailed semiquantitative region of interest analysis of the different parameter values as well as visual identification of the most conspicuous tumor areas on parameter maps, for example, areas with maximum tumor perfusion, highest metabolite ratios of choline-containing compounds/N-acetyl-aspartate, or lowest ADC values within tumor tissue. Colocalization of these areas was then assessed.
Regarding tumor vascularity-related parameters and tumor proliferation-related parameters, the higher the glioma grade the higher were the respective parameters in semiquantitative analysis. ADC values decreased with glioma grade. In the whole study population comprising low- (N = 15) and high-grade gliomas (N = 42), except for 23Na-MRI, there was good (>50%) or perfect (100%) agreement of the tumor areas with highest values on parameter images in the majority of cases (>80%), that is, tumor areas with increased thymidine-uptake and highest choline, both suggestive of increased tumor proliferation, and elevated microcirculation as demonstrated by DSC-, arterial spin-labeling-, and DCE-MRI. 23Na-MRI depicted the highest signal within necrotic tumor areas, but non-necrotic gliomas also showed a perfect agreement in more than 61%. 18F-fluorothymidine-PET, DSC-, and DCE-MRI, diffusion-weighted imaging as well as MR spectroscopic imaging correctly detected no glioma heterogeneity in all 15 histologically proven grade II gliomas but identified suspicious areas in all 3 nonenhancing grade III gliomas.
Both imaging techniques that depict microcirculation and techniques that visualize proliferation identify similar target areas.
由于脑胶质瘤的异质性，活检应针对最间变区域进行。已经提出了几种功能磁共振成像（MRI）或正电子发射断层扫描（PET）技术，用于识别最间变的肿瘤区域。然而，尚不清楚这些各种功能成像方式推荐的活检靶标是否相互对应。因此，目的是评估它们是否识别相似的靶区。
61 例疑似脑胶质瘤患者在 2.3 +/- 3.5 天内行 MRI、18F-氟胸腺嘧啶和 18F-氟脱氧葡萄糖-PET 评估。35 例患者行大体全切除，26 例行立体定向活检。MRI 在 1.5 特斯拉宽带发射/接收系统上进行，使用双共振鸟笼线圈。MRI 方案包括钠（23Na）-MRI（3D-径向投影成像）、质子波谱成像（1H-MRSI，点分辨波谱）、动脉自旋标记（ASL）灌注 MRI、动态对比增强（DCE）MRI 和单次剂量后动态磁敏感加权（DSC）灌注 MRI 钆贝葡胺。此外，还从扩散张量图像处理表观扩散系数（ADC）图。图像分析包括对不同参数值的详细半定量感兴趣区分析以及在参数图上对最明显的肿瘤区域的视觉识别，例如，肿瘤灌注最高、胆碱含量化合物/N-乙酰天冬氨酸最高的区域比。然后评估这些区域的共定位。
关于肿瘤血管生成相关参数和肿瘤增殖相关参数，脑胶质瘤分级越高，半定量分析中的相应参数越高。ADC 值随脑胶质瘤分级降低。在包括低级别（N = 15）和高级别（N = 42）脑胶质瘤的整个研究人群中，除了 23Na-MRI 外，在大多数情况下（>80%），参数图像上肿瘤区域的肿瘤区域具有较高的一致性（>50%）或完美一致性（100%），即在肿瘤区域内摄取较高的胸苷和最高的胆碱，均提示肿瘤增殖增加，以及 DSC、动脉自旋标记和 DCE-MRI 所示的微循环升高。23Na-MRI 在坏死肿瘤区域内显示出最高信号，但非坏死脑胶质瘤在超过 61%的情况下也具有完美的一致性。18F-氟胸腺嘧啶、DSC 和 DCE-MRI、弥散加权成像以及磁共振波谱成像在所有 15 例经组织学证实的 2 级胶质瘤中正确检测到没有胶质瘤异质性，但在所有 3 例非增强的 3 级胶质瘤中均识别出可疑区域。
显示微循环的两种成像技术和可视化增殖的技术均可识别相似的靶区。
