磁共振波谱成像在复发性脑胶质瘤放疗计划中的应用。

Magnetic resonance spectroscopy imaging in radiotherapy planning for recurrent glioma.

机构信息

Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.

出版信息

Med Phys. 2011 May;38(5):2724-30. doi: 10.1118/1.3574884.

DOI:10.1118/1.3574884

PMID:21776809

Abstract

PURPOSE

The purpose of this study was to investigate how incorporation of magnetic resonance spectroscopy imaging (MRSI) into radiotherapy planning would increase the target volume for patients with recurrent glioma.

METHODS

After prior standard radiotherapy, 25 patients with recurrent glioma were treated with bevacizumab and concurrent hypofractionated stereotactic radiotherapy (HFSRT), delivering 30 Gy in five fractions. MRSI were acquired for 12 patients. Areas with markedly higher choline levels relative to the levels of total creatine and N-acetylaspartate were identified and referred to as MRSI voxels with elevated metabolite ratios (EMR). Gross tumor volume (GTV) consisted of contrast-enhancing tumor on T1-weighted magnetic resonance images (MRI) and computed tomography. Clinical target volume (CTV) was GTV + 5 mm margin and MRSI voxels with EMR. Overall survival (OS) and 6-month progression free survival (PFS) for these patients were reported in a prior publication [Gutin et al., Int. J. Radiat. Oncol., Biol., Phys. 75(1), 156-163 (2009)], and the outcome was correlated with the GTV and the volume of MRSI voxels with EMR in this study.

RESULTS

Seven of the 12 patients had MRSI voxels with EMR. If none of the MRSI voxels with EMR were included, the CTV would range from 9.2 to 73.0 cm3 with a median of 31.0 cm3, whereas if all voxels were included, the CTV would range from 27.4 to 74.4 cm3 with a median of 35.0 cm3. For three of the seven patients, including the voxels with EMR, would have increased the CTV by 14%-23%. For one patient, where the MRSI voxels with EMR did not overlap the GTV, including these voxels would increase the CTV by 198%. No correlation could be found between the OS and PFS and the GTV or the volume of MRSI voxels with EMR.

CONCLUSIONS

Seven of 12 patients with recurrent glioma had MRSI voxels with EMR. For four of these seven patients, including the MRSI voxels with EMR, significantly increased the CTV. This study does not have statistical power to conclude on the importance of including areas with MRSI-suspect disease into the radiation target volume.

摘要

目的

本研究旨在探讨将磁共振波谱成像（MRSI）纳入放疗计划如何增加复发性脑胶质瘤患者的靶区。

方法

在标准放疗后，25 例复发性脑胶质瘤患者接受贝伐单抗联合低分割立体定向放疗（HFSRT）治疗，给予 30 Gy 分 5 次。12 例患者采集 MRSI。相对总肌酸和 N-乙酰天门冬氨酸水平，发现并将明显升高胆碱水平的区域标记为代谢物比值升高的 MRSI 体素（EMR）。大体肿瘤体积（GTV）由 T1 加权磁共振成像（MRI）和计算机断层扫描（CT）增强肿瘤组成。临床靶体积（CTV）为 GTV+5mm 边界和 MRSI 体素 EMR。这些患者的总生存期（OS）和 6 个月无进展生存期（PFS）在之前的研究中报道过[Gutin 等人，Int。J. Radiat. Oncol.，Biol.，Phys. 75（1），156-163（2009）]，本研究将结果与 GTV 和 MRSI 体素 EMR 体积相关联。

结果

12 例患者中有 7 例有 MRSI 体素 EMR。如果不包括任何 EMR 的 MRSI 体素，CTV 将在 9.2 至 73.0cm3 之间，中位数为 31.0cm3，而如果包括所有体素，CTV 将在 27.4 至 74.4cm3 之间，中位数为 35.0cm3。对于其中 3 例患者，包括 EMR 体素可使 CTV 增加 14%-23%。对于一名 MRSI 体素 EMR 不与 GTV 重叠的患者，包括这些体素将使 CTV 增加 198%。未发现 OS 和 PFS 与 GTV 或 MRSI 体素 EMR 体积之间存在相关性。