Planning evaluation of C-arm cone beam CT angiography for target delineation in stereotactic radiation surgery of brain arteriovenous malformations.
Planning evaluation of C-arm cone beam CT angiography for target delineation in stereotactic radiation surgery of brain arteriovenous malformations.
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DOI：
10.1016/j.ijrobp.2014.05.035
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发表时间：
2014-10-01
期刊：
影响因子：
--
通讯作者：
Ford EC
中科院分区：
文献类型：
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作者：
Kang J;Huang J;Gailloud P;Rigamonti D;Lim M;Bernard V;Ehtiati T;Ford EC
立体定向放射外科(SRS)是目前治疗脑动静脉畸形的有效方法之一。传统上，磁共振成像(MRI)、磁共振血管成像(MRA)和数字减影血管成像(DSA)相结合用于确定SRS治疗的靶区体积。本研究的目的是评价C臂锥束计算机断层扫描(CBCT)在脑动静脉畸形SRS治疗计划中的应用。在我们机构连续接受脑动静脉畸形治疗的16名患者被纳入这项回顾研究。治疗前，所有患者均接受MRA、DSA和C型臂CBCT检查。所有图像都使用GammaPlan规划系统进行了联合配准。由2名医生使用C型臂CBCT或MRA独立勾画AVM区域，得到两个体积：一个CBCT体积(VCBCT)和一个MRA体积(VMRA)。根据划定的区域生成了SRS计划。C型臂CBCT和MRA显示的治疗靶区平均体积相似，分别为6.40 cm~3和6.98 cm~3(P=.82)。然而，存在着显著的不重叠区域。平均而言，MRA与C臂CBCT的重叠仅占总体积的52.8%。在大多数情况下，基于VMRA的放射计划没有为C臂CBCT上确定的区域提供足够的剂量；VCBCT的平均最小剂量为29.5%，而预期目标为45%(P<；.001)。在基于C臂CBCT的计划中，接受12GY或更多照射的正常脑的平均体积并不大于基于MRA的计划。与MRA/MRI图像相比，C臂CBCT图像的使用显著改变了用于SRS规划的AVM的区域。基于CT的计划可以在不增加对正常脑的剂量的情况下完成，并且可能代表了对病灶的更准确的定义，增加了成功消除的机会。
Stereotactic radiation surgery (SRS) is one of the therapeutic modalities currently available to treat cerebral arteriovenous malformations (AVM). Conventionally, magnetic resonance imaging (MRI) and MR angiography (MRA) and digital subtraction angiography (DSA) are used in combination to identify the target volume for SRS treatment. The purpose of this study was to evaluate the use of C-arm cone beam computed tomography (CBCT) in the treatment planning of SRS for cerebral AVMs. Sixteen consecutive patients treated for brain AVMs at our institution were included in this retrospective study. Prior to treatment, all patients underwent MRA, DSA, and C-arm CBCT. All images were coregistered using the GammaPlan planning system. AVM regions were delineated independently by 2 physicians using either C-arm CBCT or MRA, resulting in 2 volumes: a CBCT volume (VCBCT) and an MRA volume (VMRA). SRS plans were generated based on the delineated regions. The average volume of treatment targets delineated using C-arm CBCT and MRA were similar, 6.40 cm3 and 6.98 cm3, respectively (P = .82). However, significant regions of nonoverlap existed. On average, the overlap of the MRA with the C-arm CBCT was only 52.8% of the total volume. In most cases, radiation plans based on VMRA did not provide adequate dose to the region identified on C-arm CBCT; the mean minimum dose to VCBCT was 29.5%, whereas the intended goal was 45% (P<.001). The mean volume of normal brain receiving 12 Gy or more in C-arm CBCT-based plans was not greater than in the MRA-based plans. Use of C-arm CBCT images significantly alters the delineated regions of AVMs for SRS planning, compared to that of MRA/MRI images. CT-based planning can be accomplished without increasing the dose to normal brain and may represent a more accurate definition of the nidus, increasing the chances for successful obliteration.