Geant4 Version Research Articles

TU-C-BRB-04: A Monte Carlo-Based Small Animal Dosimetry Platform for Pre-Clinical Trials: Proof of Concept

Purpose: The development of novel agents for targeted radionuclide therapy has led to an important need for accurate dosimetry characterization during pre‐clinical trials. The purpose of this study is to discuss our progress in developing a fully automated Monte Carlo‐based dosimetry platform for external and/or internal absorbed dose quantification in small animals. Methods: The dosimetry platform was built entirely around the Monte Carlo code Geant4 version 9.3. CT and PETimage datasets of a mouse injected with CLR1404, a novel tumor target pharmaceutical that is tagged with both I‐124 and I‐131 for imaging and therapy, were used for this preliminary study. The activity distribution in the tumor acquired from the PET scan was modeled as a simple spherical source. The same CTimage set was used to generate external dose distributions from a 6 MV photon beam spectrum. Results: The external dose distributions from the 6 MV photon source and the internal dose distributions from CLR1404 were combined to get a relative dose distribution within the mouse. Conclusions: We provided a proof‐of‐concept for a fully automated dose calculation platform in small animals that can be used for developing protocols for pre‐clinical trials. We are currently working on additional modifications to better represent both the external beam source for our small animal irradiator as well as the activity distributions gathered by the PET scan.

Comparison of electron scattering algorithms in Geant4**Presented as part of the International Workshop on Recent Advances in Monte Carlo Techniques for Radiation Therapy, Montreal, 2011.

Electron scattering algorithms in Geant4 versions 9.4 and 9.5 were benchmarked by comparing scattered distributions against previously measured values at 13 and 20 MeV, for low, intermediate, and high atomic number materials. Several scattering models were used: Versions 93 and 95 of the Urban model, with different step size limits near boundaries; Goudsmit–Saunderson multiple scattering; and single scattering. The Urban93 and Urban95 models with a large step size limit (as in the Option 0 physics list) were found to give results most closely matching the experimental results. Scattered distributions using the Urban models were all narrower than measured by up to 6%, consistent with previous published simulations using EGSnrc. This is suggestive of a systematic difference between simulations and measurement. The magnitudes of the differences were similar to previously published results using Geant4, although there were differences in detail. In particular, the current results were typically 2% narrower than values. Results with the more restrictive step size limit in Option 3 were even more narrow, and close to those with single scattering. The Goudsmit–Saunderson multiple scattering model produced distributions up to 15% different from measured in Geant4 version 9.5 and up to 45% different in Geant4 version 9.4.

Geant4 hadronic physics for space radiation environment

Purpose: To test and to develop Geant4 (Geometry And Tracking version 4) Monte Carlo hadronic models with focus on applications in a space radiation environment.Materials and methods: The Monte Carlo simulations have been performed using the Geant4 toolkit. Binary (BIC), its extension for incident light ions (BIC-ion) and Bertini (BERT) cascades were used as main Monte Carlo generators. For comparisons purposes, some other models were tested too. The hadronic testing suite has been used as a primary tool for model development and validation against experimental data.Results: The Geant4 pre-compound (PRECO) and de-excitation (DEE) models were revised and improved. Proton, neutron, pion, and ion nuclear interactions were simulated with the recent version of Geant4 9.4 and were compared with experimental data from thin and thick target experiments.Conclusions: The Geant4 toolkit offers a large set of models allowing effective simulation of interactions of particles with matter. We have tested different Monte Carlo generators with our hadronic testing suite and accordingly we can propose an optimal configuration of Geant4 models for the simulation of the space radiation environment.

SU‐E‐T‐18: Nanoscale Proton Dose Distributions Using GEANT4‐DNA Simulation

Purpose: To simulate the energy deposition patterns of 1 MeV proton beam in three different nanoscale size spherical water targets. Methods: In this study, GEANT4 version 9.4 with the DNA physics package demonstrated in one of the advanced examples “microdosimetry” was used. In order to mimic typical cell geometry, three spherical targets of water with diameters of 200, 20 and 2 nanometer were placed in a cube of water (10 × 10 × 10 micrometer3). The interactions listed in the DNA package were applied to these three spherical targets where secondary electrons were tracked down to 5 eV. The standard electromagnetic interaction processes were used in the volume of the cube outside the spherical targets. Proton beams of 1 MeV were used to travel through the spherical targets. One thousand incident proton histories per spherical target were studied in the simulations. The frequency distributions of energy deposited (eV) per nanometer in the Results: With the decrease of the of the target dimensions, the shapes of the frequency distribution of the energy depositions per nanometer in the spherical targets were observed to gradually become asymmetric. The mean energy depositions were found to be 29, 24.5 and 14.8 eV/nanometer for 200, 20 and 2 nanometer diameter targets, respectively. Conclusions: The energy deposition patterns at the DNA environment directly affect sub‐cellular radiation damage and lesion repair mechanism and thus are essential for biophysics models to estimate the radiobiological effects. The trend of increasing asymmetry showed in this study in dose distributions for smaller nanoscale target demonstrate the usefulness of GEANT4‐DNA package as a powerful tool to better understand the physical basis of dose deposition in realistic size of DNA to accurately predict the cellular radiobiological effect due to particle irradiation.

SU-E-T-712: An Antiproton Depth-Dose Curve Benchmark of Geant4

Purpose: Experimental and theoretical studies of the potential use of antiproton beams for cancer therapy have been greatly aided by Monte Carlo based calculations. Previously published data from the AD‐4/ACE collaboration has shown excellent agreement between the Fluka Monte Carlo code and experimental absorbed dose data. In this research we investigate the suitability of the open source Geant4 Monte Carlo package for antiproton absorbed dose calculations.Methods: Ionization chamber depth‐dose data collected at the CERN Antiproton Decelerator and previously published by Bassler et al were used as the experimental benchmark. Version 9.3.p01 of Geant4 and Fluka version 2008.3b‐02 were used. The antiproton beam was incident on a 20 × 20 × 20 cm3 water phantom with parameters set to match the experimental 126 MeV beam at CERN as closely as possible. Several reference physics lists were used covering electromagnetic and nuclear physics processes.Results: Geant4 consistently placed the Bragg peak at the correct depth, but the shape of the depth‐dose curve was inaccurate overall, regardless of physics lists chosen. In some cases, the peak‐to‐plateau ratio was off by an order of magnitude with fully enabled hadronic physics. This appeared to be the result of excessive in‐flight annihilation and a corresponding overproduction of secondaries as well as a dearth of at‐rest antiproton annihilations. Conclusions: Currently Geant4 does appear to have the necessary physics implemented, however in‐flight annihilation cross sections and low energy annihilation thresholds seem to be off in its default reference or standard physics lists. We plan to help improve this by sharing data and working with Geant4 developers.

Recent improvements on the description of hadronic interactions in Geant4

We present an overview of recent improvements of hadronic models in Geant4 for the physics configurations (Physics Lists) relevant to applications in high energy experiments. During last year the improvements have concentrated on the study of unphysical discontinuities in calorimeter observables in the transition regions between the models used in Physics Lists. The microscopic origin of these have been investigated, and possible improvements of Geant4 code are currently under validation. In this paper we discuss the status of the latest version of Geant4 with emphasis on the most promising new developments, namely the Fritiof based and CHIPS Physics Lists.

Comparison of GATE/GEANT4 with EGSnrc and MCNP for electron dose calculations at energies between 15 keV and 20 MeV

The GATE Monte Carlo simulation platform based on the GEANT4 toolkit has come into widespread use for simulating positron emission tomography (PET) and single photon emission computed tomography (SPECT) imaging devices. Here, we explore its use for calculating electron dose distributions in water. Mono-energetic electron dose point kernels and pencil beam kernels in water are calculated for different energies between 15 keV and 20 MeV by means of GATE 6.0, which makes use of the GEANT4 version 9.2 Standard Electromagnetic Physics Package. The results are compared to the well-validated codes EGSnrc and MCNP4C. It is shown that recent improvements made to the GEANT4/GATE software result in significantly better agreement with the other codes. We furthermore illustrate several issues of general interest to GATE and GEANT4 users who wish to perform accurate simulations involving electrons. Provided that the electron step size is sufficiently restricted, GATE 6.0 and EGSnrc dose point kernels are shown to agree to within less than 3% of the maximum dose between 50 keV and 4 MeV, while pencil beam kernels are found to agree to within less than 4% of the maximum dose between 15 keV and 20 MeV.

A closed-form solution for the two-dimensional transport equation by the LTSN nodal method in the energy range of Compton effect

In the present work we report on a closed-form solution for the two-dimensional Compton transport equation by the LTS N nodal method in the energy range of Compton effect. The solution is determined using the LTS N nodal approach for homogeneous and heterogeneous rectangular domains, assuming the Klein–Nishina scattering kernel and a multi-group model. The solution is obtained by two one-dimensional S N equation systems resulting from integrating out one of the orthogonal variables of the S N equations in the rectangular domain. The leakage angular fluxes are approximated by exponential forms, which allows to determine a closed-form solution for the photons transport equation. The angular flux and the parameters of the medium are used for the calculation of the absorbed energy in rectangular domains with different dimensions and compositions. In this study, only the absorbed energy by Compton effect is considered. We present numerical simulations and comparisons with results obtained by using the simulation platform GEANT4 (version 9.1) with its low energy libraries.

Comparison of GEANT4 very low energy cross section models with experimental data in water

The GEANT4 general-purpose Monte Carlo simulation toolkit is able to simulate physical interaction processes of electrons, hydrogen and helium atoms with charge states (H0, H+) and (He0, He+, He2+), respectively, in liquid water, the main component of biological systems, down to the electron volt regime and the submicrometer scale, providing GEANT4 users with the so-called "GEANT4-DNA" physics models suitable for microdosimetry simulation applications. The corresponding software has been recently re-engineered in order to provide GEANT4 users with a coherent and unique approach to the simulation of electromagnetic interactions within the GEANT4 toolkit framework (since GEANT4 version 9.3 beta). This work presents a quantitative comparison of these physics models with a collection of experimental data in water collected from the literature. An evaluation of the closeness between the total and differential cross section models available in the GEANT4 toolkit for microdosimetry and experimental reference data is performed using a dedicated statistical toolkit that includes the Kolmogorov-Smirnov statistical test. The authors used experimental data acquired in water vapor as direct measurements in the liquid phase are not yet available in the literature. Comparisons with several recommendations are also presented. The authors have assessed the compatibility of experimental data with GEANT4 microdosimetry models by means of quantitative methods. The results show that microdosimetric measurements in liquid water are necessary to assess quantitatively the validity of the software implementation for the liquid water phase. Nevertheless, a comparison with existing experimental data in water vapor provides a qualitative appreciation of the plausibility of the simulation models. The existing reference data themselves should undergo a critical interpretation and selection, as some of the series exhibit significant deviations from each other. The GEANT4-DNA physics models available in the GEANT4 toolkit have been compared in this article to available experimental data in the water vapor phase as well as to several published recommendations on the mass stopping power. These models represent a first step in the extension of the GEANT4 Monte Carlo toolkit to the simulation of biological effects of ionizing radiation.

MO-E-BRB-07: Relative Biological Effectiveness of Proton - An Empirical Model Prediction

Purpose: To propose a simple Relative Biological Effective (RBE) model for proton that describes the RBE as a function of proton depth, dose, and the linear energy transfer (LET). Methods and Materials: Radiobiological parameters α and β were obtained by fitting the published experimental proton cell survival data where the surviving fraction (SF) as a function of dose (D) is given by SFSF(D) = exp(−αD − βD 2 ). The RBE defined as the ratio of photondose over protondose (D x /D p ) for the same SF, is given in the present model by, RBE = α x 2 − 4β x LnSF − α x α p 2 − 4β p LnSF − α p × β p β x where α p = α 0 + 1 − e −λ 1 * LET 2 λ 2 * LET and β p = β x . A software program gnuplot with the Levenberg‐Marquardt algorithm was used to fit the experimental data with the empirical formula mentioned above by minimizing χ2 with the selection of suitable parameters (λ1, λ2, α0). The dose average LET values were calculated for 250 MeV proton in water using GEANT4 (version 4.9.3) Monte Carlo simulation code. The model was then used to calculate the RBE values as a function of depths that includes the Bragg peak depths of 250 MeV protons, where the increasing RBE with depths causes an extended biological effective dose in the distal falloff range. Results: The best fit parameters obtained were α0=0.1 Gy−1, λ1=0.0013 (keV/μm)−2 and 2=0.045 (keV/μm)−1⋅Gy. The model was found to be able to reproduce the measured RBE values as a function of LET and dose. The biological effective dose (physical dose multiplied by RBE) as a function of depths for 250 MeV incident proton shows that the shift in the depth of distal edge at 90% level of physical dose is 1 mm. Conclusions: The new model is providing an improved understanding of the RBE as a function of depth, dose and LET for proton beam.

WE-E-201C-04: Development of the First MGH Proton Range Telescope (PRaT) Prototype Using Scintillating Fibers

Purpose: To describe the development of the first MGH proton range telescope (PRaT) prototype using scintillating fibers. Monte Carlo simulations were used to assess the image quality of this PRT. Materials & Methods: Standard commercially available scintillating fibers from Saint Gobain have been used to build the X/Y mesh of the PRaT. Fiber optic detectors are extremely cheap to build therefore the opto-scintillator design may be easily replaced or improved over time with minimal cost. GEANT4 (G4) version 9.0.p01 (2007) was used to simulate a proton radiograph of an actual patient lung tumor. For each primary proton entering the patient, the energy, position and direction cosines were recorded. Primary or secondary particles exiting the patient were then correlated to the ones entering the patient using a Track ID number. Results: The energy resolution of the PRaT was within 3MeV for protons ranging from 70MeV to 200MeV, while the spatial resolution was 2 to 3mm, depending on the coincidence parameters of the electronics. Initial studies used 1–3 MHz through-put electronics. While, using 10–30MHz electronic, 1–2mm spatial resolution could be achieved. G4 simulations show that spatial resolution of photon X-ray images is superior, allowing better viewing of the edges of the various organs such the lung chest wall, the supra-clavicle collar bones, etc. The poor spatial resolution is an intrinsic limitation of the proton range telescope due to multiple Coulomb scattering. On the other hand, the PRT allows better visualization of tissue density changes within soft and bone tissue regions such as the lung and supra-clavicle region. Conclusions: The first PRaT prototype using scintillating fiber was developed at MGH. Our preliminary results of evaluating the PRaT with G4 Monte Carlo toolkit showed that it can produce images with fair spatial resolution, while offering very good edge detection within soft tissue.

Validation and verification of Geant4 standard electromagnetic physics

The software tools developed for the validation and verification of the standard electromagnetic physics package of Geant4 are described. The validation is being performed versus experimental data and in regression to a previous version of Geant4. Examples of validation results are presented.

Influence of Geant4 parameters on dose distribution and computation time for carbon ion therapy simulation

The aim of this work was to study the influence of Geant4 parameters on dose distribution and computational time for simulations of carbon ion therapy. The study was done using Geant4 version 9.0. The dose distribution in water for incident monoenergetic carbon ion beams of 300 MeV/u were compared for different values of secondary particle production threshold and different step limits. Variations of depth dose of about 2 mm were observed in some cases, which induced a 30% variation of dose deposit in the Bragg peak region. Other tests were done using Geant4 version 9.2 to verify the results from this study. The two versions provided converging results and led to the same conclusions.

A solution for the two-dimensional transport equation for photons and electrons in a rectangular domain by the Laplace transform technique

In the first part of this paper, we describe a review in the Laplace transform technique applied to SN two-dimensional transport equation in a rectangular domain considering Compton scattering. In Compton scattering the incident photon interacts with an electron of the irradiated medium, giving the electron kinetic energy, and also producing a scattered photon. In order to track that electron, in the second part of this paper, we apply the PN approximation to X,Y-geometry electron transport problems. In this derivation, the energy deposited by the free electron is taken into account. To reach this objective we solve two model problems: the first one for the transport of photons, assuming the Klein-Nishina scattering kernel as the scattering differential cross-section as well as the multigroup model in the energy variable; and the second one for the transport of free electrons considering the screened Rutherford scattering kernel. The results are presented under absorbed energy form in several points of interest. We report numerical simulations and comparisons with results obtained by using the Geant4 version 9.1 program which applies the Monte Carlo's technique to low energy libraries for both two-dimensional problems.

Multiple scattering of 13 and 20 MeV electrons by thin foils: A Monte Carlo study with GEANT, Geant4, and PENELOPE

In this work, recent results from experiments and simulations (with EGSnrc) performed by Ross et al. [Med. Phys. 35, 4121-4131 (2008)] on electron scattering by foils of different materials and thicknesses are compared to those obtained using several Monte Carlo codes. Three codes have been used: GEANT (version 3.21), Geant4 (version 9.1, patch03), and PENELOPE (version 2006). In the case of PENELOPE, mixed and fully detailed simulations have been carried out. Transverse dose distributions in air have been obtained in order to compare with measurements. The detailed PENELOPE simulations show excellent agreement with experiment. The calculations performed with GEANT and PENELOPE (mixed) agree with experiment within 3% except for the Be foil. In the case of Geant4, the distributions are 5% narrower compared to the experimental ones, though the agreement is very good for the Be foil. Transverse dose distribution in water obtained with PENELOPE (mixed) is 4% wider than those calculated by Ross et al. using EGSnrc and is 1% narrower than the transverse dose distributions in air, as considered in the experiment. All the codes give a reasonable agreement (within 5%) with the experimental results for all the material and thicknesses studied.

SU‐FF‐T‐430: Comparison of Dose Volume Histograms From Selected Proton Therapy Treatments Between Geant4.5.0 and Geant4.9.0 Monte Carlo Simulations with and Without Dynamic Densities

Introduction: In order to reduce computation time for proton Monte Carlo dose calculations, our group has introduced a method to improve the voxel navigation algorithm in Geant4.5.0 and to dynamically assign material density in a given voxel element during particle transport. In the meantime, we have developed a new fast voxel navigation technique tailored to Geant4.9.0. Furthermore, Geant4.9.0 shows differences in the physics setup and tracking algorithm compared to the Geant4.5.0. Thus, the aim of this study was to assess whether defining all material densities corresponding to a given HU from the CT scan, i.e. without applying dynamic densities, would significantly impact the runtime for the new Geant4 version. In this study we compare dose‐volume histograms as well as runtime from selected proton therapy treatments between Geant4 Monte Carlo calculations using Geant4.5.0 with the dynamic density method and Geant4.9.0 without the dynamic density method. Methods and Materials: The two plans considered in this study were a spinal cord astrocytoma treatment and a prostate treatment. The differences between the Monte Carlo simulations with and without dynamic densities for each treatment were evaluated by plotting the dose‐volume histograms of the PTV and several other organs‐at‐risk considered in the treatment plan. In addition, the dose contours for each treatment and the contour differences were evaluated. Results: There are small discrepancies between dose calculations with and without dynamic densities, particularly in the GTV of both treatments. These discrepancies may suggest problems with the dynamic density method or problems with the CT conversion process used for generating the patient geometry. Conclusion: A comparison of dose calculations using Geant4.5.0 (including improved voxel navigation and dynamic density algorithm) and using Geant4.9.0 (including our new voxel navigation algorithm and no dynamic density algorithm) yields slight but not clinically significant differences with comparable run time.

SU‐FF‐T‐434: Neutron and Photon Fluence Distributions and Ambient Dose Equivalents for 250 MeV Proton Interactions in Tissue Using Geant4 Monte Carlo Code

Purpose: To simulate interaction of 250 MeV protons in tissues using GEANT4 (version 4.8.3) Monte Carlo code that utilizes electromagnetic and hadronic interactions to determine the energy and angular distributions of generated neutron and photon and calculate H*(10) ambient dose equivalent for shielding purposes. Materials and Methods: A cylindrical phantom (length=42 cm, radius=21 cm, ICRU 4‐element soft tissue) was placed in vacuum. A spherical scoring geometry surrounding the phantom with radius = 100 cm was implemented. The energy of generated neutron, and photon crossing this geometry was counted in 9 theta bins (twenty degree each). The physics list consisted of electromagnetic; elastic; inelastic for proton, neutron and heavy ions. Common to all were standard electromagnetic for gamma, electron and positron; low‐energy parameterized electromagnetic for proton and ions; low‐energy parameterized nuclear elastic (G4LElastic) for proton and ions; and low energy parameterized inelastic for ions and binary cascade nuclear inelastic for proton. The elastic and inelastic processes for neutrons with energy higher than 4 eV (G4NeutronHPorLEModel) and lower than 4 eV (G4NeutronHPThermalScattering Data available in library G4NDL3.1) were used for computation. The ambient dose equivalent, H*(10), was calculated as a product of particle fluence, Φ, with the fluence to dose equivalent conversion factor available in the ICRP 74 report (1996). Results: The total number of generated particles per incident proton was 0.208 for neutron and 0.57 for photon. The neutron fluence (energy < 5 MeV) per proton was dominant in forward compared to lateral and backward directions. No substantial directional preferences were observed for photon fluence. H*(10) from neutron are in the forward (59%), backward (6.3%) and lateral directions (34.7%). H*(10) from photon was 7.2% to that from neutron. Conclusions: Monte Carlo simulations thus provided an improved understanding of the directional dependence of neutron and photon spectral fluences and dose equivalents.

SU‐FF‐T‐400: Monte Carlo Simulations of Compact Plasma Accelerators for Proton Radiotherapy

Purpose: One common characteristic of the compact plasma proton accelerators is a broad energy spectrum which can not be used directly for radiotherapy. The purpose of this study is to analyze the effect of the geometrical parameters of the treatment head components, their materials, and the magnetic field configuration, on the proton and neutron dose distributions to identify an optimal design for the plasma proton accelerator's treatment head and provide important feedback to ongoing plasma proton experiments. Method and Materials: Calculations of proton dose distributions and the neutron dose equivalent were performed using Monte Carlo simulations by irradiating a water phantom with protons in the energy range of 175 to 250 MeV. The simulations were performed using the Geant4 (version 4.9.2) toolkit. The input spectra were experimental energy spectra scaled to energies relevant for radiotherapy, having a broad Gaussian distribution. Results: We have designed a collimating system, magnetic field region, energy selector, and shielding components for a plasma accelerated proton therapy system. The collimating and energy selector systems are needed in order to achieve proton dose distributions superior to the conventional X‐ray radiotherapy distributions. It is shown that a great number of unwanted electrons and photons is stopped by a sequence of tungsten absorbing disks placed inside the collimating and energy selector systems. Also, a sequence of three boronated polyethylene layers is shown to substantially capture the secondary neutrons. Dose deposited by neutrons in the water phantom is found to be 6 orders of magnitude lower than the dose deposited by protons, thus giving negligible contribution to the integral dose. Conclusion: We have studied the design of the plasma proton accelerator's treatment head. It is shown that the proposed system is capable of delivering clinically relevant proton dose distributions. The implemented shielding components ensure extremely low neutron dose distributions.

SU‐FF‐T‐450: Verification of the GEANT4 Monte Carlo Code in Low Energy Photon Transport

Purpose: GEANT4 is a powerful and versatile general‐purpose Monte Carlo code. The reliability of GEANT4 in high energy photon transport has been largely confirmed. On the other hand, the discrepancy to other Monte Carlo codes in low energy range has also been reported in the past years. The purpose of this investigation is to explore the performance of GEANT4 at low photon energies (< 50 KeV), and to verify the recent improvements of GEANT4 in photon physics. Method and Materials: The MCNP Monte Carlo code will be used as the reference in this study. The physics of dominant photon interactions in low energy range (Photoelectric effect, Compton scattering, and Rayleigh scattering) implemented in the two codes and the corresponding cross section/attenuation coefficient data will be compared. The production of fluorescent photons, which play an important role in dose deposition of KV photons, will be especially addressed. Simplified cases involving 125I/103Pd or KV X‐ray beam will be modeled and simulated with both MCNP and the latest version of GEANT4 to exemplify the extent of influence under various situations. Results: Detailed physics descriptions are required for modeling low energy photon transport in Monte Carlo codes. Differences in physics implementation between MCNP and GEANT4 are known. These differences could induce noticeable differences in radiation dose and particle flux. Conclusion: GEANT4 has been gradually accepted to be a very useful Monte Carlo simulation tool to tackle many problems in radiation therapy. A comprehensive study of KV photon transport provides verification of the reliability of the code in the low energy range, and will potentially boost the applications of GEANT4 in radiotherapy modalities such as eye plaque therapy, prostate seed implant brachytherapy, and intraoperative radiotherapy (IORT).

Validation of Geant4 Low Energy Electromagnetic Processes Against Precision Measurements of Electron Energy Deposition

A comparison of energy deposition profiles produced by Geant4-based simulations against calorimetric measurements is reported, specifically addressing the low energy range. The energy delivered by primary and secondary particles is analyzed as a function of the penetration depth. The experimental data concern electron beams of energy between approximately 50 keV and 1 MeV and several target materials of atomic number between 4 and 92. The simulations involve different sets of physics process models and versions of the Geant4 toolkit. The agreement between simulations and experimental data is evaluated quantitatively; the differences in accuracy observed between Geant4 models and versions are highlighted. The results document the accuracy achievable in use cases involving the simulation of low energy electrons with Geant4 and provide guidance to the experimental applications concerned.