论文标题
将EGSNRC带到新的低点：EGS ++晶格几何形状的开发和微观测试
Taking EGSnrc to new lows: Development of egs++ lattice geometry and testing with microscopic
论文作者
论文摘要
目的：这项工作将新的晶格几何库EGS_LATTICE引入了EGSNRC Monte Carlo代码，该代码可用于对非常大的（以前不可行的）几何形状进行建模以及建立递归边界条件。 EGS_LATTICE以及EGSNRC的可靠性通常是交叉验证和测试的。方法：在EGS_LATTICE中定义了新的Bravais，Cutic和Hexagonal Grattice几何形状，并描述了它们的传输算法。实施了含有腔的细胞和金纳米颗粒（GNP）的模拟，以与已发表的Geant4-DNA和Penelope结果进行比较。通过立方晶格实现的递归边界条件用于执行电子扇形腔测试。结果：晶格在EGSNRC中成功实现。与GEANT4-DNA相比，EGSNRC计算出细胞质和细胞核的剂量为细胞质和核，中位差为0.6％。 EGSNRC计算了剂量与含有GNP的微观腔与剂量与含有均匀混合物的腔的比率，结果通常与Penelope一致（1％以内）。对于所有考虑的所有能量/细胞，通过FANO测试（低于0.1％）。此外，在某些情况下，用于FANO测试的递归边界条件为效率提高了超过一百万。结论：EGS_LATTICE几何库，目前可作为EGSNRC GitHub开发分支上的拉动请求可用，现在可以作为开源代码自由访问。晶格几何实现与其他MC代码中的独立模拟交叉验证，并通过电子FANO腔测试进行了验证，不仅证明了EGS_LATTICE的可靠性，而且还通过扩展，EGSNRC在纳米型中模拟传输的能力并在微观腔中进行了分数。
Purpose: This work introduces a new lattice geometry library, egs_lattice, into the EGSnrc Monte Carlo code, which can be used for both modeling very large (previously unfeasible) quantities of geometries and establishing recursive boundary conditions. The reliability of egs_lattice, as well as EGSnrc in general, is cross-validated and tested. Methods: New Bravais, cubic, and hexagonal lattice geometries are defined in egs_lattice and their transport algorithms are described. Simulations of cells and Gold NanoParticle (GNP) containing cavities are implemented to compare to published Geant4-DNA and PENELOPE results. Recursive boundary conditions, implemented through a cubic lattice, are used to perform electron Fano cavity tests. Results: Lattices are successfully implemented in EGSnrc. EGSnrc calculated doses to cell cytoplasm and nucleus when irradiated by an internal electron source with a median difference of 0.6% compared to Geant4-DNA. EGSnrc calculated the ratio of dose to a microscopic cavity containing GNPs over dose to a cavity containing a homogeneous mixture of gold, and results generally agree (within 1%) with PENELOPE. The Fano test is passed (sub-0.1%) for all energies/ cells considered. Additionally, the recursive boundary conditions used for the Fano test provided a factor of over a million increase in efficiency in some cases. Conclusions: The egs_lattice geometry library, currently available as a pull request on the EGSnrc GitHub develop branch, is now freely accessible as open-source code. Lattice geometry implementations cross-validated with independent simulations in other MC codes and verified with the electron Fano cavity test demonstrate not only the reliability of egs_lattice, but, by extension, EGSnrc's ability to simulate transport in nanometer geometries and score in microscopic cavities.
