Department of Radiation Oncology, New York-Presbyterian Hospital/Weill Cornell Medical College, 525 E 68th St., Box 25, New York, NY 10065, USA.
Technol Cancer Res Treat. 2010 Aug;9(4):347-58. doi: 10.1177/153303461000900405.
In this paper, we review the applications of functional magnetic resonance imaging (MRI) for target delineation and critical organ avoidance for brain radiotherapy. In this article we distinguish functional MRI from brain functional MRI (fMRI). Functional MRI includes magnetic resonance spectroscopic imaging (MRSI), perfusion MRI, diffusion tensor imaging (DTI) and brain fMRI. These functional MRI modalities can provide unique metabolic, pathological and physiological information that are not available in anatomic MRI and can potentially improve the treatment outcomes of brain tumors. For example, both choline (Cho) to N-acetylaspartate (NAA) and Cho to creatine (Cr) ratios from MRSI increase with increasing tumor malignancy and can be used to grade gliomas. Relative cerebral blood volume (rCBV) measurements from dynamic susceptibility contrast perfusion magnetic resonance imaging (DSC MRI) are superior to conventional contrast-enhanced MRI in predicting tumor biology and may be even superior to pathologic assessment in predicting patient clinical outcomes. Brain fMRI can help identify and avoid functionally critical areas when constructing treatment plans for brain radiotherapy. In the past, functional MRI measurements have not been routinely used in a clinical arena due to the experimental nature of these imaging modalities. As these methods become more commonly used and effective image co-registration algorithms become available, integration of functional MRI into the treatment process of brain radiotherapy now appears to be clinically feasible, at least in major medical centers.
在本文中，我们回顾了功能磁共振成像（fMRI）在脑放射治疗靶区勾画和关键器官保护中的应用。在本文中，我们将功能 MRI 与脑功能 fMRI（fMRI）区分开来。功能 MRI 包括磁共振波谱成像（MRSI）、灌注 MRI、弥散张量成像（DTI）和脑 fMRI。这些功能 MRI 模式可以提供独特的代谢、病理和生理信息，这些信息在解剖 MRI 中不可用，并且可以潜在地改善脑肿瘤的治疗效果。例如，MRSI 中的胆碱（Cho）与 N-乙酰天冬氨酸（NAA）的比值和 Cho 与肌酸（Cr）的比值随着肿瘤恶性程度的增加而增加，可用于对胶质瘤进行分级。来自动态磁敏感对比灌注磁共振成像（DSC MRI）的相对脑血容量（rCBV）测量在预测肿瘤生物学方面优于常规对比增强 MRI，甚至在预测患者临床结果方面优于病理评估。脑 fMRI 有助于在制定脑放射治疗计划时识别和避免功能关键区域。过去，由于这些成像模式的实验性质，功能 MRI 测量并未在临床领域常规使用。随着这些方法的应用越来越广泛，并且有效的图像配准算法变得可用，将功能 MRI 整合到脑放射治疗过程中现在似乎在临床上是可行的，至少在主要的医疗中心是如此。
