近距离放射治疗中感兴趣能量范围内单能光子点源在水中的剂量分布：使用PENELOPE和GEANT4的蒙特卡罗模拟

使用Monte Carlo代码PENELOPE和GEANT4的$^{32}$ P血管内近距离放射治疗源导丝的剂量学表征

Dosimetry characterization of $^{32}$P intravascular brachytherapy source wires using Monte Carlo codes PENELOPE and GEANT4

已使用代码PENTAGE PE和GEANT 4进行蒙特卡罗计算，以表征Guidant Corporation生产的基于$^{32}$ P β源的新型20 mm长导管的剂量测定参数。计算了沿横轴的剂量分布和二维剂量率表。此外，在参考点的剂量率，径向剂量函数和各向异性函数进行了评估，根据适应TG-60形式主义的圆柱形源。首先根据与旧27 mm Guidant $^{32}$ P Beta源对应的先前结果验证PENELOPE和GEANT 4代码。对于PENTLEPE和GEANT 4，27 mm无鞘源在水中参考点的剂量率分别计算为$0.215 \pm 0.001$ cGy s $^{-1}$ mCi $^{-1}$和$0.2312 \pm 0.0008$ cGy s $^{-1}$ mCi $^{-1}$。对于无鞘20 mm源，这些值分别为$0.2908 \pm 0.0009$ cGy s $^{-1}$ mCi $^{-1}$和$0.311 \pm 0.001$ cGy s $^{-1}$ mCi $^{-1}$。此外，与此新的来源有限的数据进行了比较。我们发现，PENDENT PE和GEANT 4获得的结果之间存在不可忽略的差异。

用PENELOPE计算NE2571、NE2571A和NE2581A套管电离室的电子束质量$k_{{\rm Q,Q}_0}$因子

Computation of the electron beam quality $k_{{\rm Q,Q}_0}$ factors for the NE2571, NE2571A and NE2581A thimble ionization chambers using PENELOPE

计算了NE 2571、NE 2571 A和NE 2581 A三种套管电离室的电子束质量修正因子$k_{Q,Q_{0}}$。Monte Carlo代码PENTHAL PE用于估计这些腔室的总体校正因子$f_{\rm c,Q}$，用于标称能量范围在6和22 MeV之间的电子束，对应于Varian Clinac 2100 C/D。使用$^{60}$ Co光束作为参考质量${\rm Q}_0$。还考虑了8个单能电子束再现质量指数$R_{50}$的Clinac束。$k_{Q,Q_{0}}$因子计算为$f_{\rm c,Q}$和$f_{{\rm c,Q}_0}$之间的比值。NE 2571电离室的计算结果与Muir和Rogers用EGSnrc计算的结果吻合得很好。由于它发生在其他电离室分析在以前的作品中，$k_{{\rm Q,Q}_0}$的因素，发现单能束是大于（小于）比那些对应于Clinac束在低（高）$R_{50}$值，差异略高于$0.5\%$。最后，在NE 2571 A灭菌室中获得的$k_{{\rm Q,Q}_0}$因子系统地比其前身灭菌室NE 2571低约0.5%。

Investigation of physical dose enhancement in core-shell magnetic gold nanoparticles with TOPAS simulation

The application of metal nanoparticles as sensitization materials is a common strategy that is used to study dose enhancement in radiotherapy. Recent in vitro tests have revealed that magnetic gold nanoparticles can be used in cancer therapy under a magnetic field to enhance the synergistic efficiency in radiotherapy and photothermal therapy. However, magnetic gold nanoparticles have rarely been studied as sensitization materials. In this study, we obtained further results of the sensitization properties of magnetic gold nanoparticles using the Monte Carlo method TOPAS and TOPAS-nBio. We analy…

Heterogeneous multiscale Monte Carlo simulations for gold nanoparticle radiosensitization

To introduce the heterogeneous multiscale (HetMS) model for Monte Carlo simulations of gold nanoparticle dose-enhanced radiation therapy (GNPT), a model characterized by its varying levels of detail on different length scales within a single phantom; to apply the HetMS model in two different scenarios relevant for GNPT and to compare computed results with others published. The HetMS model is implemented in EGSnrc; the code is tested via comparisons with published data from independent gold nanoparticle (GNP) simulations. Two distinct scenarios for the HetMS model are considered: (1) monoenerge…