Basic evaluation of a novel 4D target and human body phantom
Basic evaluation of a novel 4D target and human body phantom
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DOI：
10.1088/1361-6560/ab259c
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发表时间：
2019-07-01
影响因子：
3.5
通讯作者：
Kunieda，E.
中科院分区：
文献类型：
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作者：
Matsumoto，Y.;Kabuki，S.;Kunieda，E.
立体定向体放射治疗（SBRT）通常是用动态幻体或实体幻体来验证的，但现在需要能够准确模拟个体肿瘤动态的幻体，以便对每个患者进行定制验证。我们开发了一种新的4D动态靶幻影（多细胞4D幻影），可以模拟患者的肿瘤运动。实验验证了该模型的基本质量和动态再现性。新开发的多细胞4D幻影主要由软组织、骨骼、肺和肿瘤（靶）四个部分组成。基于一名男性的计算机断层扫描（CT）数据，建立了其幻肢结构。在这项研究中，我们研究了一个多细胞4D幻影的基本性能。幻影的所有CT数字与人体数据非常接近。几何最大振幅分别为4.57 mm、4.59 mm和3.68 mm。几何误差分别为0.84、0.58和0.40 mm。腹部表面运动稳定60 s。重复测量表明，多次测量之间的目标运动没有实际差异，表明高再现性（r> 0.97）。使用Gafchromic薄膜的端到端测试显示伽马通过率为98%或以上（2mm /3%）。虽然目前我们的假体在患者肿瘤的运动中表现出有限的再现性，但总体上证实了令人满意的精度水平。这是一个非常有前途的装置，用于验证放射治疗的移动目标。
Stereotactic body radiation therapy (SBRT) is usually verified with a dynamic phantom or solid phantom, but there is a demand for phantoms that can accurately simulate tumor dynamics within an individual that would allow customized validation in every patient. We developed a new 4D dynamic target phantom (multi-cell 4D phantom) that allows simulation of tumor movement in patients. The basic quality and dynamic reproducibility of this new phantom was verified in this investigation. The newly developed multi-cell 4D phantom comprises four main components: soft tissue, bones, lungs, and tumor (target). The phantom structure was based on computed tomography (CT) data of a male. In this study, we investigated the basic performance of a multi-cell 4D phantom. All the CT numbers of the phantom were very close to those of human data. The geometric maximum amplitudes were 4.57 mm in the lateral direction, 4.59 mm in the ventrodorsal direction, and 3.68 mm in the cranio-caudal direction. Geometric errors were 0.84, 0.58, and 0.40 mm, respectively. Movements of the abdominal surface were stable for 60 s. Repeated measurements show no actual differences in target movements between multiple measurements and indicated high reproducibility (r> 0.97). End-to-end tests using Gafchromic film revealed a gamma pass rate of 98% or above (2 mm/3%). Although our phantom performed limited reproducibility in the movement of the patient tumor at present, a satisfactory level of precision was confirmed in general. This is a very promising device for use in the verification of radiation therapy for moving targets.