Treatment Planning using Physiologic MRI Data

描述（由申请人提供）：本申请要求支持整合生理磁共振成像（MRI）方法，以更好地描述和描绘多形性胶质母细胞瘤（GBM）脑肿瘤，为放射治疗做准备。我们假设使用这些成像方法将导致更精确的放射治疗计划。提出的研究是基于广泛的初步数据，表明化学移位成像（CSI）、灌注和扩散成像以及基于mri的缺氧映射增加了关于肿瘤生理学的额外信息，可以纳入治疗计划，以降低肿瘤复发率。虽然已知T2 MRI上的异常区域与肿瘤的显微镜下扩散有关，但其中一些异常表示没有恶性细胞的水肿，而其他区域可能含有高浓度的恶性细胞，应纳入治疗容积。虽然大多数恶性脑肿瘤在放射治疗范围内复发，但20- 25%的复发发生在这些领域之外。因此，我们预计至少有25%的患者会出现10%左右的容积差异。我们预计，至少一些这些场外复发可以通过使用成像技术来预测。因此，成像技术将用于识别每个肿瘤中可能具有高复发风险的“高危亚区”。放疗完成后，对患者进行系列生理性MRI扫描；研究终点为首次复发。具体目的是：1)使用血氧水平依赖（BOLD） MRI结合碳呼吸，在单个肿瘤内创建缺氧图。2)利用化学位移成像（CSI）探测肿瘤的增殖潜能。3)利用造影增强灌注MRI评估肿瘤血管生成特征。4)利用弥散加权MRI评估肿瘤的细胞结构。比较AIMS 1-4中创建的地图的位置和区域。6)从AIM 5定义的区域生成临床靶体积（CTV’s）。

DESCRIPTION (provided by applicant): This application requests support to integrate physiologic magnetic resonance imaging (MRI) methods to better describe and delineate glioblastoma multiforme (GBM) brain tumors in preparation for radiation therapy treatment. We hypothesize that the use of these imaging methods will result in more precise radiotherapy treatment planning. The proposed research is based upon extensive preliminary data indicating chemical shift imaging (CSI), perfusion and diffusion imaging and MR-based hypoxia mapping add additional information about tumor physiology that can be incorporated into a treatment plan with the goal of decreasing the rate of tumor recurrence. Although regions of abnormality on T2 MRI are known to correlate with microscopic spread of tumor, some of this abnormality represents edema without malignant cells while other areas may contain a high concentration of malignant cells that should be incorporated into the treatment boost volume. While most malignant brain tumors recur within the radiation treatment fields, 20- 25% of recurrences occur outside of these fields. For this reason, we expect that in at least 25% of patients there will be a boost volume discrepancy > 10%. We anticipate that at least some of these out-of-field recurrences could be predicted by the use of the imaging techniques. Thus, the imaging techniques will be used to identify "high-risk subvolumes" within each tumor, which may be at high risk of recurrence. After completing radiotherapy, patients will be followed with serial physiologic MRI scans; the study endpoint being the first recurrence. The SPECIFIC AIMS are: 1) Create maps of hypoxia within individual tumors using blood oxygen level dependent (BOLD) MRI combined with carbogen breathing. 2) Probe the proliferative potential of tumors using chemical-shift imaging (CSI). 3) Assess the angiogenic features of a tumor using contrast enhanced perfusion MRI. 4) Assess the cellularity of a tumor using diffusion-weighted MRI. 5) Compare the locations and areas of maps created in AIMS 1-4. 6) Generate clinical target volumes (CTV's) from the regions defined by AIM 5.