Imaging as a Biomarker for Diffuse Intrinsic Brainstem Gliomas

非侵入性监测生物或代谢活动的理想方法是 脑干尚未建立。用于评估脑组织的现有方法（例如， PET）应用于脑干时有局限性。新的非侵入性成像方法是 目前正在研究。我们正在使用动态磁敏感对比MR灌注，动态 增强MRI、质子核磁共振波谱成像和FDG PET， 探讨脑桥胶质瘤的影像学特点。有四个临床试验 目前属于这个项目。几乎所有患有CNS肿瘤的儿科患者都经历了 至少在其中一项研究中进行广泛的成像。在过去的一年里，我们证明了 在临床试验中使用标准MRI定义缓解的困难， 根据这些结果，提出了对这些患者的临床获益的新定义。 对治疗的反应以及因此新的顺铂的功效通常使用 遵循WHO标准或最近使用RECIST进行二维肿瘤测量 的搜索.尚未验证RECIST标准用于测量儿科CNS肿瘤 并且二维测量仍然是联合试验中的标准。我们比较 四个独立盲法测量弥漫性桥脑胶质瘤的1D、2D和3D 读者结果表明，所有测量值均存在显著的变异性（0- 197 因此肿瘤大小的变化是临床试验反应的不良指标。我们 还通过电子方式调查了全国的儿科肿瘤学家和神经肿瘤学家， 国家确定肿瘤测量的标准实践。我们的研究结果表明， 没有标准的测量方法用于测量这些病变。我们有 发表了一份报告，建议使用FLAIR图像来测量DIPG，并将这些图像进行比较。 进行最佳反应扫描图像应该并排比较。中央审查 也被推荐用于涉及DIPG的临床试验。我们正在继续评估 附加MR序列的实用性，包括灌注和光谱成像， 尝试定义特定成像技术（例如光谱学，PET）在这些方面的作用 患者

The ideal method for non-invasive monitoring of biological or metabolic activity in the brainstem has not yet been established. Existing methods for evaluating cerebral tissue (e.g. PET) have limitations when applied to the brainstem. New noninvasive imaging methods are currently being studied. We are using dynamic susceptibility contrast MR perfusion, dynamic enhanced MRI, proton nuclear magnetic spectroscopic imaging, and FDG PET to further investigate the imaging characteristics of pontine gliomas. There are four clinical trials which currently fall under this project. Nearly all pediatric patients with CNS tumors undergo extensive imaging on at least one of these studies. Over the past year, we have demonstrated the difficulty in using standard MRI for definition of response in clinical trials and have proposed a new definition of clinical benefit for these patients based on these results. Response to treatment and therefore efficacy of new gents is typically measured using two-dimensional tumor measurements following WHO criteria, or more recently, using RECIST criteria. RECIST criteria have not been validated for the measurement of pediatric CNS tumors and two-dimensional measurements continue to be the standard in consortium trials. We compared the 1D, 2D and 3D measurements of diffuse intrinsic pontine gliomas by four separate blinded readers. The results show that there is significant variability (0-197%) in all measurements and change in tumor size is therefore a poor indicator of response for clinical trials. We have also electronically surveyed pediatric oncologists and neuro-oncologists across the country to determine the standard practice of tumor measurement. Our results show that there is no standard measurement method being used in the measurement of these lesions. We have published a report recommending the use of FLAIR images to measure DIPG and comparing these with the best response scans on study. Images should be compared side by side. Central review was also recommended for clinical trials involving DIPG. We are continuing to evaluate the utility of additional MR sequences, including perfusion and spectroscopic imaging in an attempt to define the role of specific imaging techniques (e.g. spectroscopy, PET) in these patients.