3D MRSI for resected high-grade gliomas before RT: Tumor extent according to metabolic activity in relation to MRI
3D MRSI for resected high-grade gliomas before RT: Tumor extent according to metabolic activity in relation to MRI
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DOI：
10.1016/j.ijrobp.2003.08.023
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发表时间：
2004-05-01
影响因子：
7
通讯作者：
Nelson, SJ
中科院分区：
文献类型：
--
作者：
Pirzkall, A;Li, XJ;Nelson, SJ
目的：通过 MRI 和磁共振波谱成像 (MRSI) 评估高级别胶质瘤患者手术后但放疗 (RT) 前是否存在残留病灶，并评估 MRSI 对定义 RT 治疗计划术后靶区的影响。 方法和材料：30 例患者（27 例多形性胶质母细胞瘤，3 例 III 级星形细胞瘤）在术后 4 周内但开始 RT 之前接受了 MRI 和 MRSI。 MRI 数据是手动绘制轮廓的；感兴趣区域包括T-2加权高信号（T-2）、T-1加权对比增强（T-1）和切除腔（RC）。根据胆碱-N-乙酰-天冬氨酸指数（CNI）分析三维 MRSI 数据中的胆碱和 N-乙酰-天冬氨酸（NAA）水平。 CNI 和其他代谢指标作为三维轮廓叠加在 MRI 数据上。为 T-1 和 T-2 定义复合、联合和不相交体积，有/无 RC，并在 CNI 轮廓内，对应于值 2。此外，检查了后续 MRI 研究的新发对比度增强，并与 RT 之前获得的初始光谱结果进行比较。结果：在 MRI 和 MRSI 体积之间的空间关系中发现了显着变化。 10 名患者术后无对比增强，MRSI 显示 10 名患者中有 8 名代谢活动异常，平均 20 cm(3)，超出 RC 11-36 mm。在 20 名具有对比增强病变的患者中，T-1 和 CNI2 之间发现了显着差异； 19 名患者的代谢活动落在造影剂增强范围之外，平均为 21 cm(3)，并超出造影剂增强范围 8-33 mm。对于所有患者来说，T-2 涵盖了大部分代谢量。然而，在没有对比增强的 10 名患者中，有 6 名（平均 8 cm(3)；最大 15-23 mm）和 20 名对比增强患者中的 13 名（平均 7 cm(3)；最大 8-22 mm），CNI2 延伸超出了 T-2，这表明 T-2 体积增加了 180%（中位数 13%）和 86%（中位数 14%）。分别为非对比度增强和对比度增强患者。 MRI 随访检查的初步评估显示，10 名非对比增强患者中有 8 名新的对比增强区域与初始 MRSI 异常相对应。此外，CNI 体积与新对比增强开始的时间呈反比。结论：MRSI 是评估高级别胶质瘤手术切除后残留病灶的有价值的诊断工具。将代谢异常区域纳入术后患者的治疗计划将为初级体积和增强体积产生不同大小和形状的目标体积。它还可能鼓励使用不均匀的边距来定义范围。肿瘤细胞浸润，而不是目前使用的均匀边缘。 (C) 2004 年爱思唯尔公司。
Purpose: To evaluate the presence of residual disease after surgery but before radiotherapy (RT) in patients with high-grade glioma by MRI and magnetic resonance spectroscopy imaging (MRSI) and to estimate the impact of MRSI on the definition of postoperative target volumes for RT treatment planning.Methods and Materials: Thirty patients (27 glioblastoma multiforme, 3 Grade III astrocytoma) underwent MRI and MRSI within 4 weeks after surgery but before the initiation of RT. The MRI data were manually contoured; the regions of interest included T-2-weighted hyperintensity (T-2), T-1-weighted contrast enhancement (T-1), and the resection cavity (RC). Levels of choline and N-acetyl-aspartate (NAA) in the three-dimensional MRSI data were analyzed on the basis of a choline-to-N-acetyl-aspartate index (CNI). The CNI and other metabolic indexes were superimposed on the MRI data as three-dimensional contours. Composite, conjoint, and disjoint volumes were defined for T-1 and T-2, with/without RC, and within the CNI contour, corresponding to a value of 2. In addition, follow-up MRI studies were examined for new onset contrast enhancement and compared with the initial spectroscopic findings obtained before RT.Results: Substantial variation was found in the spatial relationship between the MRI and MRSI volumes. Ten patients had no contrast enhancement after surgery, and MRSI revealed abnormal metabolic activity in 8 of 10, averaging 20 cm(3) and extending 11-36 mm beyond the RC. In 20 patients with contrast-enhancing lesions, substantial variation was found between T-1 and CNI2; metabolic activity fell outside the contrast enhancement in 19 patients, averaging 21 cm(3) and extending 8-33 mm beyond the contrast enhancement. For all patients, the T-2 encompassed most of the metabolic volume. However, the CNI2 extended beyond the T-2 in 6 of 10 patients without contrast enhancement (mean, 8 cm(3); maximum, 15-23 mm) and in 13 of 20 patients with contrast enhancement (mean, 7 cm(3); maximum, 8-22 mm), representing an increase in the T-2 volume by as much as 180% (median 13%) and 86% (median 14%) for non-contrast-enhancing and contrast-enhancing patients, respectively. Preliminary evaluation of the MRI follow-up examinations revealed correspondence of areas of new contrast enhancement with initial MRSI abnormalities in 8 of 10 non-contrast-enhancing patients. In addition, CNI volumes correlated inversely with the time to onset of new contrast enhancement.Conclusion: MRSI is a valuable diagnostic tool for the assessment of residual disease after surgical resection in high-grade glioma. The incorporation of areas of metabolic abnormality into treatment planning for postoperative patients would produce different sizes and shapes of target volumes for both primary and boost volumes. It also may encourage the use of nonuniform margins to define the extent. of tumor cell infiltration, rather than the current use of uniform margins. (C) 2004 Elsevier Inc.