3D-pintable lung phantom for distal falloff verification of proton Bragg peak
3D-pintable lung phantom for distal falloff verification of proton Bragg peak
复制标题
用于质子布拉格峰远端衰减验证的 3D-pintable 肺模型
DOI：
10.1002/acm2.12706
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Sakae T.
中科院分区：
文献类型：
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作者：
Koketsu J;Kumada H;Takada k;Takei H;Mori Y;Kamizawa S;Hu Yuchao;Sakurai H;Sakae T.
在质子治疗中，据报道质子束的布拉格峰在穿过异质结构（例如人类肺部）时恶化。先前的研究使用异质随机体素体模，其中软组织和空气被随机分配以使体模具有与人肺相同的密度，用于进行蒙特卡罗（MC）模拟。然而，由于其难以制造的形状，这些体模的测量是复杂的。在本研究中，我们使用Voronoi镶嵌设计一个可以制造的体模，并准备了一个Voronoi肺体模，测量和MC计算都是可能的。我们的目的是评价该体模作为一种新的肺部体模用于研究质子束布拉格峰退化的有效性。为此，我们测量并计算了通过体模的百分比深度剂量和远端衰减宽度（DFW）。对于155 MeV射束，使用Voronoi肺体模测量和计算的DFW值分别为0.40和0.39 cm。对于200 MeV射束，使用Voronoi肺体模测量和计算的DFW值均为0.48 cm。我们的研究结果表明，无论是测量和MC计算与塑化肺样品从人体在以前的研究中表现出很高的重现性。我们发现，使用Voronoi肺体模比使用其他以前的体模获得了更好的结果。所设计的体模对提高测量精度具有重要意义。本研究表明，Voronoi肺体模是有用的模拟质子束恶化的肺部结构的不均匀性的影响。
In proton therapy, the Bragg peak of a proton beam reportedly deteriorates when passing though heterogeneous structures such as human lungs. Previous studies have used heterogeneous random voxel phantoms, in which soft tissues and air are randomly allotted to render the phantoms the same density as human lungs, for conducting Monte Carlo (MC) simulations. However, measurements of these phantoms are complicated owing to their difficult‐to‐manufacture shape. In the present study, we used Voronoi tessellation to design a phantom that can be manufactured, and prepared a Voronoi lung phantom for which both measurement and MC calculations are possible. Our aim was to evaluate the effectiveness of this phantom as a new lung phantom for investigating proton beam Bragg peak deterioration. For this purpose, we measured and calculated the percentage depth dose and the distal falloff widths (DFW) passing through the phantom. For the 155 MeV beam, the measured and calculated DFW values with the Voronoi lung phantom were 0.40 and 0.39 cm, respectively. For the 200 MeV beam, the measured and calculated DFW values with the Voronoi lung phantom were both 0.48 cm. Our results indicate that both the measurements and MC calculations exhibited high reproducibility with plastinated lung sample from human body in previous studies. We found that better results were obtained using the Voronoi lung phantom than using other previous phantoms. The designed phantom may contribute significantly to the improvement of measurement precision. This study suggests that the Voronoi lung phantom is useful for simulating the effects of the heterogeneous structure of lungs on proton beam deterioration.