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0001 =========================================================
0002 Text version of the Hadrontherapy README file
0003 =========================================================
0004
0005 Last revision: November 2024
0006
0007
0008 'hadrontherapy' example is supported by the Italian INFN
0009 Institute in the framework of the Geant4 INFN experiment
0010
0011 ----------------------------------------------------------------------------
0012 GEANT 4 - Hadrontherapy example
0013 ----------------------------------------------------------------------------
0014
0015 MAIN AUTHORS
0016 ====================
0017 G.A.P. Cirrone(a)*, L. Pandola(a), G. Petringa(a), S.Fattori(a), A.Sciuto(a)
0018 *Corresponding author, email to pablo.cirrone@lns.infn.it
0019
0020
0021 ==========> PAST CONTRIBUTORS <==========
0022
0023 R.Calcagno(a), G.Danielsen (b), F.Di Rosa(a),
0024 S.Guatelli(c), A.Heikkinen(b), P.Kaitaniemi(b),
0025 A.Lechner(d), S.E.Mazzaglia(a), Z. Mei(h), G.Milluzzo(a),
0026 M.G.Pia(e), F.Romano(a), G.Russo(a,g),
0027 M.Russo(a), A.Tramontana (a), A.Varisano(a)
0028
0029 (a) Laboratori Nazionali del Sud of INFN, Catania, Italy
0030 (b) Helsinki Institute of Physics, Helsinki, Finland
0031 (c) University of Wallongong, Australia
0032 (d) CERN, Geneve, Switzwerland
0033 (e) INFN Section of Genova, Genova, Italy
0034 (f) Physics and Astronomy Department, Univ. of Catania, Catania, Italy
0035 (g) CNR-IBFM, Italy
0036 (h) Institute of Applied Electromagnetic Engineering(IAEE)
0037 Huazhong University of Science and Technology(HUST), Wuhan, China
0038
0039 -------------------------------------------------------------------------------------------------
0040
0041 HADRONTHERAPY:
0042 WHAT IT IS, WHAT IT DOES AND WHAT IT WILL PROVIDE
0043 ===================================================
0044
0045 'hadrontherapy' is a Geant4-based application specifically developed to address typical needs related to proton and ion therapy.
0046 Its first release was in 2004. At that time 'hadrontherapy' was only capable of simulating a well-specified proton therapy facility: the passive transport beam line installed at Laboratori Nazionali del Sud (INFN) in Catania, Italy.
0047
0048 Today Hadrontherapy, except that it is in continuous development, is more flexible and shows many additional capabilities with respect to the past.
0049 Its geometrical set-up, for example, is now completely interchangeable permitting a simple switch between different geometrical configurations, which all share the same phantom (sensitive detector) with the related features.
0050 It is possible to do a simulation of a generic proton/ion transport beam line and laser-driven beam line. In this release, a module for dose average LET and RBE computations have been also included.
0051
0052 The configurations are:
0053
0054 - Passive proton beam line, which is installed at the LNS-INFN facility in Catania for eye tumor treatment with protons at 62 MeV. It is simulated in PassiveProtonBeamLine.cc; (G.A.P. Cirrone et al., IEEE Nuclear Science Symposium Conference Record, 2003, 3, pp. 1756-1758, J2-5)
0055
0056 - Passive carbon beam line, which is the simulation of the transport beam line at LNS-INFN of Catania for experiments with ion beams (Carbon, Oxygen and Helium). It is simulated in PassiveCarbonBeamLine.cc;
0057
0058 - Laser-driven beam line, which is the simulation of a beam line for the focusing, the handling and the transport of a laser-driven beam, a Faraday Cup is the eligible detector for this class. It is simulated in LaserDrivenBeamLine.cc;
0059 (A.Tramontana et al., A transport beamline solution for laser-driven proton beams
0060 6th International Particle Accelerator Conference, IPAC 2015, 2015, pp. 2515-2518)
0061
0062 - TIFPA passive proton beam line, which is installed at the Protontherapy Center of Trento (Italy), used for experiments with proton beams. Geometry is implemented in HadrontherapyTIFPAPassiveProtonBeamLine.cc
0063 (F.Tommasino et al., A new facility for proton radiobiology at the Trento proton therapy centre: Design and implementation, Physica Medica 58 (2019) 99–106)
0064
0065 - BEST passive proton beam line is the beamline INFN-LNS is developing for the BEST Cyclotron company for eye tumor treatment with 70 MeV protons. The geometry is implemented in BESTPassiveProtonBeamline.cc.
0066
0067 In PassiveProtonBeamLine.cc, in PassiveCarbonBeamLine.cc, in LaserDrivenBeamLine.cc,in HadrontherapyTIFPAPassiveProtonBeamLine.cc and in BESTPassiveProtonBeamline.cc, the user can change the geometrical characteristics of beam line elements.
0068 Alternatively, the user can use the macro file.
0069
0070 Folder structure of 'hadrontherapy'
0071
0072 'hadrontherapy' distribution contain different sub-folders:
0073
0074 \src: where source .cc files are stored
0075
0076 \include: where header .hh files are stored
0077
0078 \macro: where a set of ready-to-use macro files are provided
0079
0080 \field: where a set of ready-to-use.TABLE files are provided. These files are generated from OPERA & COMSOL codes for the laser-driven beam line.
0081
0082 \experimentalData: in this directory, a set of reference (both experimental and analytical) data are stored.
0083
0084 \data\rbe: contains the file lem1.csv including the alpha and beta values and rbe resulted from the radiobiological Local Effect Model (LEM) for three cell lines ( AG01522, U87 and HSG)
0085
0086 Description of the \macro folder
0087
0088 Inside the "macro" folder, different macro files are provided.
0089 In particular, five macro files are related to the different beam lines:
0090
0091 defaultMacro.mac: permits to run a simulation using the default geometry, i.e. the CATANA proton beam line in Catania. A 62 MeV gaussian proton beam with 0.25 MeV sigma and 0.028° as divergence (sigma) is launched.
0092 You can modify by macro the range shifter thickness you
0093 want to select. The entrance of the phantom is positioned at the isocentre ( (0,0,0)
0094 coordinates). LET and RBE computation are activated.
0095
0096 carbon_beamline.mac: reproduces a simple passive beam line for the use of carbon, oxygen and helium ion beams for multidisciplinary applications (selectGeometry Carbon). A parallel 62 MeV/u carbon beam with 0.740 MeV/u sigma is simulated.
0097
0098 laserDrivenBeamline.mac: simulates a typical laser-driven proton spectrum as input for a beam line made of a quadrupole system, an energy selector and a Faraday Cup (selectGeometry LaserDriven)
0099
0100
0101 Trento_parameters.mac: reproduces the experimental beam line installed at the Trento protontherapy centre and implements a typical source.
0102
0103 BestBeamLine.mac: implements the elements of the beam line developed for the BEST company and simulates a 70 MeV proton beam as input of the simulation. Dose and LET longitudinal distributions are computed at the isocentre and a native dose scorer is also added to retrieve the lateral dose profiles.
0104
0105 3 additional macro files are also included:
0106
0107 modulatorMacro.mac : allows the reconstruction of the spread out bragg peak modulating the proton beams by means of a rotating modulator wheel. The wheel is rotated of 1 degree at each run and 1000 protons are simulated in each run.
0108 stoppingPowers.mac : calculates the stopping power of protons and alpha particles in the energy range between 1 keV up to 200 MeV
0109 detectorGeometry.mac : example of how to modify the detector geometry
0110
0111 The main folder also includes an additional macro file, batch.mac which runs a simple simulation using the default geometry of the CATANA beamline.This macro is also used during the system testing process.
0112
0113 DOWNLOAD AND INSTALLATION
0114 ===================================================
0115
0116 'hadrontherapy' source code is released inside the distribution of the Geant4 toolkit in the $G4INSTALL/examples/advanced folder.
0117
0118 To run 'hadrontherapy' you must first install the Geant4 package. Once Geant4 is installed, the example must be first compiled. When the compilation is completed the program can be executed.
0119
0120 A complete guide for the Geant4 installation in different operating systems can be found inside the official installation Geant4 pages.
0121
0122 A CMakeLists.txt file (preferred) is provided together with a standard GNUmakefile for compilation.
0123
0124 GEOMETRIC SET-UP
0125 ===================================================
0126
0127 The idea of 'hadrontherapy' is to provide a tool useful for Users interested in the field of proton and ion therapy. These can include the simple calculation of dose distribution curves in water or other materials, the derivation of important transport parameters (stopping powers, ranges, etc.) in different geometrical set-ups and for different materials, up to the complete simulation of a real transport beam line for therapy.
0128 The main component of the simulation is the phantom, a box that can be filled with different materials and where the scoring of different information (at moment the dose deposited in voxels) can be performed. A more complete description of the phantom is given in the next subsection.
0129
0130 All these configurations will be set using macro commands.
0131
0132 There is also a feature that allows the user to make a choice between alternative geometry set-ups. This can be done by using the command:
0133 /geometrySetup/selectGeometry <name>
0134 where <name> is either "default" for the standard 'hadrontherapy' geometry, "Carbon" for INFN-LNS transport beam line, normally used for interdisciplinary researches at LNS-INFN in Catania with carbon and other ion beams, "LaserDriven" for the laser-driven beam line, "TrentoLine" for the TIFPA beam line and "BESTBeamLine" for the beam line designed for the BEST company.
0135
0136 At the end of the beam line a phantom (a box of uniform material) is reproduced. Inside it, a user-defined region is divided into cubic and identical voxels. The voxel size can be varied as well as the voxelized region.
0137 At the end of a simulation run, the dose deposited by primaries and secondaries in each voxel is collected. This information is available as an .out file.
0138 The default size of the active voxelized region is 40x40x40 mm and actually the default voxel configuration is 200 x 1 x 1, which means 200 slices with 0.2 mm of thickness.
0139 Of course, this default can be modified in order to obtain, for example, a matrix of 80x80x80 cubic voxels each with a lateral dimension of 0.5 mm.
0140
0141 Concerning the cut and stepMax values, the default configuration implies a cut value of 1 mm in the whole world (use the command /run/setCut <length> in order to set the cut for all, and the command /run/setCutForRegion <name> <length> to set the cut for the desired volume (<name>) only) and a stepMax of 0.01 mm just in the phantom and in other volumes of the laser-driven beam line (use the command /Step/waterPhantomStepMax 0.01 mm).
0142 In any case, it is strongly recommended to use a stepMax value not bigger than 5% of the dose slice thickness.
0143
0144 THE PROTON PASSIVE LINE CLASS FILE
0145 ===================================================
0146
0147 The following is the description of the elements of the passive proton beam line of the INFN, Laboratori Nazionali del Sud in Catania (I). This line is completely simulated inside this class.
0148
0149 The main elements are:
0150
0151 * The SCATTERING SYSTEM: to transversally enlarge the original beam
0152 * The COLLIMATORS: placed along the beam line to collimate the beam;
0153 * The RANGE SHIFTERS: to decrease the energy of the primary proton beam to a specific value;
0154 * The MODULATOR WHEEL: to modulate the energy of the primary and mono-energetic beam into a wide spectrum. The energy modulation is necessary to homogeneously irradiate a tumour volume that can extend in depth up to 20 mm;
0155 * The MONITOR CHAMBERS: very thin ionisation chamber that permits the dose monitoring during the patient irradiation;
0156 * The MOPI detector: microstrips, air-free detector utilised for the check of the beam symmetry during the treatment;
0157 * The PATIENT COLLIMATOR: a brass, tumour-shaped collimator able to confine the proton irradiation field to irradiate just the tumour mass in the transverse direction;
0158
0159 The user can vary, via messenger, almost all the geometrical characteristics of the beam line elements (i.e. their position along the beam line, their thickness, etc.).
0160
0161 The elements simulated in the PassiveBeamLine.cc file are:
0162
0163 1. A scattering system, to spread geometrically the beam;
0164
0165 2. A system of collimators, to avoid the scattering radiation;
0166
0167 3. A modulation system that spreads the beam in energy and produces the so-called spread-out Bragg peak; It is constituted by a rotating wheel of different thicknesses. The wheel rotates around its axis (parallel to the proton beam axis) and its movement can be obtained employing a messenger between runs.
0168
0169 4. A set of monitor chambers (special transmission ionization chambers used to control the particle flux during the irradiation);
0170
0171 5. A final long collimator and a patient collimator defining the final shape of the beam before reaching the patient.
0172
0173 6. A water phantom: it is a box of water where the dose deposit is calculated. The use of the water phantom is required by the international protocol on the measure of dose in the case of proton and ion beams (IAEA 398, 2000).
0174
0175 THE CARBON PASSIVE LINE CLASS FILE
0176 ===================================================
0177
0178 The PassiveCarbonBeamLine.cc class implements the Zero Degree (ZD) beamline installed at LNS-INFN and entirely dedicated to in-air irradiation with ion beams (Z > 1, E ≤ 80AMeV ).
0179 The beam line is composed of an exit 50 um Kapton window which separates the in vacuum pipe from the in air section. The beam then hits a scattering system composed by a 20 um tantalum foil and a brass central stopper. Moreover, two different systems for the beam modulation energy are simulated reproducing the available systems at LNS-INFN: a ripple filter specifically designed for 62 AMeV carbon ion beams and a ridge filter designed for 62 AMeV helium and oxygen ion beams. A transmission monitor ionization chamber providing the on-line monitoring of the delivered dose is also simulated.
0180 The final collimator system is then composed by a brass tube (50 cm long and 27 mm in diameter) and a brass collimator with a variable in diameter from a maximum of 27 mm to 1 mm.
0181 RIDGE FILTER
0182 The ridge filter consists in a 2D array of pins, whose the shape and the thickness is optimized to obtain the desired SOBP.
0183 The developed and simulated ridge filter is composed of 900 pins, each having a square base of 1.7 x 1.7 mm2 and height of 4.72 mm. The material chosen for its realization was plastic (C21 O4 N24) with a density of 1.18 g/cm3. The filter was designed and produced thanks to a collaboration between the INFN-LNS group and the GSI, Darmstadt(D). The reconstruction of the ridge geometry was obtained by superimposed native structures (with a trapezoid shape) already presented in Geant4 (G4Trp).
0184
0185 RIPPLE FILTERS
0186 ===================================================
0187
0188 Due to the native norrower bragg peak of carbon ions with respect to protons, a configuration with two ripple filters is the most suggested for realizing a SOBP.
0189 This solution was adopted at the ZD beam line and implemented in the simulation to obtain a flat longitudinal dose profile with carbon ions: the first filter is positioned at 7 cm from the exit window and the second one at 10 cm from the first. A single structure has a triangular section with a thin base of plexiglass (200 mm x 200 mm x 0.3 mm) and a basis 3 mm in thickness. The material density is 1.19 g/cm3.
0190
0191
0192 LASER DRIVEN PROTON BEAMLINE
0193 ===================================================
0194
0195 Nowadays a big effort is being devoted to optically accelerate charged particles. There are several ion acceleration regimes that are being discussed in literature, but up to now the most experimentally investigated is the Target Normal Sheath Acceleration (TNSA) one.
0196 The beam transport and focusing as well as the energy selection of these laser produced beams represents one of the critical points in order to make such beams suitable for clinical applications. In fact, in contrast to conventional accelerators, the beams produced by high intensity laser-matter interaction are typically characterized by a wide angular divergence (for example ± 25 degrees) and a 100 % energy spread.
0197 Moreover due to the high current, conventional dosimetric systems cannot be used during the experimental sections (saturation issues) and for this reason the faraday cup detector has been proposed as the elegible absolute dosimetric device.
0198
0199 The following is the description of the elements of the laser-driven beam line. This line is completely simulated inside this class.
0200
0201 The main elements are:
0202
0203 * The QUADRUPOLES SYSTEM: made of four quadrupoles, to focus/defocus protons with a different energy;
0204 * The COLLIMATORS: placed along the beam line to collimate the beam;
0205 * The ENERGY SELECTOR SYSTEM: made of four dipoles, that provide the spatial separation of charged particles with different energies;
0206 * The FARADAY CUP: that provide the charge measurement and the distribution of the secondary electrons;
0207
0208 The user can have the possibility to vary, via messenger, many characteristics of the beam line elements (i.e. their position along the beam line, their thickness, etc.).
0209
0210 - /LaserDriven/EnergySelector/Disable -> to disable the Energy Selector
0211
0212 - /LaserDriven/EnergySelector/FirstCollimator/Radius <value> -> to set the Radius of the first collimator
0213 - /LaserDriven/EnergySelector/FirstCollimator/thickness <value> -> to set the Thickness of the first collimator
0214 - /LaserDriven/EnergySelector/FirstCollimator/zPosizion <value> -> to set the position of the first collimator hole along the radial plane
0215
0216 - /LaserDriven/EnergySelector/SecondCollimator/Radius <value> -> to set the Radius of the second collimator
0217 - /LaserDriven/EnergySelector/SecondCollimator/thickness <value> -> to set the Thickness of the second collimator
0218 - /LaserDriven/EnergySelector/SecondCollimator/zPosizion <value> -> to set the position of the second collimator hole along the radial plane
0219
0220 - /LaserDriven/EnergySelector/Slit/thickness <value> -> to set the Thickness of the slit, maximum value 10mm for geometric constraintconstrain
0221 - /LaserDriven/EnergySelector/Slit/HoleDimensionY <value> -> to set the Y dimension of the Slit Hole
0222 - /LaserDriven/EnergySelector/Slit/HoleDimensionZ <value> -> to set the Z dimension of the Slit Hole
0223 - /LaserDriven/EnergySelector/Slit/HolePositionZ <value> -> to set the Slit hole position in the Z direction as respect the Slit body center
0224
0225 - /LaserDriven/Quadrupoles/DisableQuad -> to disable the Quadrupole system
0226
0227 PHYSICS PROCESSES AND PHYSICS MODELS IMPLEMENTATION
0228 ===================================================
0229
0230 Using the builder concepts of Geant4 we assembled (and tested) two different
0231 Physics Lists that are particuilarly suited for Hadronterapy applications:
0232
0233 'HADRONTHERAPY_1' is more suited for protons only
0234 'HADRONTHERAPY_2' is suggested for better precision with ions
0235
0236 NOTE: to activate the "_HP" physics you have to set the G4PARTICLEHPDATA environment
0237 variable pointing to the external dataset named "G4TENDL".
0238
0239 The Reference physics lists (already present in the Geant4 kernel) can
0240 be used as well. In this case the more suitable "Reference physics lists" are:
0241 "QBBC", "QGSP_BIC", "Shielding", "QGSP_BERT",
0242 "QGSP_BIC_AllHP" and "QGSP_BIC_HP"
0243
0244
0245 All the lists can be activated inside any macro file using the command:
0246 /Physics/addPhysics
0247
0248 Examples of usage are:
0249 /Physics/addPhysics HADRONTHERAPY_1 or /Physics/addPhysics QGSP_BIC_HP
0250
0251
0252 INTERACTIVE COMMANDS
0253 ===================================================
0254
0255 How to change Phantom and Detector geometries
0256
0257 In order to let the user change phantom and detector geometries and voxelization, some interactive commands have been provided. All parameters are mandatory, except those inside square brackets.
0258
0259 Detector geometry
0260
0261 The user can change:
0262
0263 (1) The detector (box) size.
0264
0265 (2) The voxels sizes. Changing these parameters, and/or the detector sizes, users should choose values in order to be divisors of the detector correspondent sizes.
0266 For both above commands, zero or negative values mean << don't change it >>
0267
0268 (3) The displacement between the phantom and the detector. Displacement parameters refer to the lower-left corner of the detector with respect to that of the phantom, by the point of view of the beam. In this case, zero or positive values are allowed, while the negatives ones mean: << don't change it>>.
0269
0270 Command synopsis:
0271
0272 /changeDetector/size <dimX> <dimY> <dimZ> <[unit]>
0273 /changeDetector/voxelSize <dimX> <dimY> <dimZ> <[unit]>
0274 /changeDetector/displacement <dispX> <dispY> <dispZ> <[unit]>
0275
0276 Default size values are 4x4x4 cm for the detector, 0.2x40x40 mm for any voxel and 0x18x18 cm for the displacement.
0277 where the X dimension is that along the beam direction
0278
0279 Phantom geometry
0280
0281 (1) The phantom size. As usually, zero or negative values mean: <<don't change it>>.
0282 (2) The phantom position respects the world. In this case, specified values refer to the three components of the position of the phantom's centre respect to the world.
0283
0284 Command synopsis:
0285
0286 /changePhantom/size <dimX> <dimY> <dimZ> <[unit]> # 40 40 40 cm
0287 /changePhantom/position <posX> <posY> <posZ> <[unit]> # 20 0 0 cm
0288
0289 All these commands must be followed by the command /changePhantom/update
0290 to check and eventually apply changes to the real geometry.
0291 Moreover, they must be issued between runs (so where you want but after the /run/initialize initialization command, or the G4State_Idle Geant4 state machine).
0292 Obviously, all the previous sizes must be set in order to maintain the detector fully inside the phantom, otherwise, the system will give an error message.
0293
0294 Some examples follow:
0295
0296 /changeDetector/size 40 0 0 cm
0297 # Will extend detector X size to cover in full the phantom X size
0298
0299 /changeDetector/size 0 4.5 0 cm
0300 # Will extend the Y size to 4.5 cm (note that voxel size Y is automatically
0301 # rounded to 4.5 cm because the default value along Y is 4 cm)
0302 /changePhantom/update
0303 # Remember to always update the geometry before the beamOn command!!
0304
0305 /changeDetector/size 0 8 0 cm
0306 # Will extend the Y size to 8 cm. In this case voxel size Y doesn't change, but
0307 # the number of voxels along Y doubles.
0308 /changePhantom/update
0309
0310 /changeDetector/voxelSize 100 0 0 um
0311 # 100 um should be a divisor of detector size X
0312 # Will change only slabs X size to 100 um, without affecting the other.
0313 /changePhantom/update
0314
0315 /changeDetector/displacement 0 0 0 # default unit mm
0316 # Will place the detector in the left lower corner (from the point of view of the beam) of #the phantom.
0317 /changePhantom/update
0318
0319 Stopping powers calculation
0320
0321 The end-user can calculate, via macro command, stopping powers only for those materials inserted into G4NistMaterialBuilder class (about 300).
0322 To get stopping powers user must provide this command line on the idle interactive terminal (or into a macro file) :
0323
0324 /parameter/getstopping <G4_material> <Emin> <Emax> <nPoints> <[particle]> <[output_filename]>
0325
0326 All parameters are mandatory except those inside square brackets [].
0327 Default values for parameters inside square brackets are respectively proton and standard output (usually the user console terminal).
0328
0329 Parameters are respectively:
0330
0331 The material (NIST) name (something like G4_..., the complete list of elements and materials is available into the G4NistMaterialBuilder class and can be printed to the terminal screen via the macro command: /parameter/nist )
0332 Kinetic energy range in MeV and the number of data points to be retrieved (in a logarithmically uniform space)
0333 The particle name (proton, e+, e-, He3, neutron,... a full list can be produced via the macro command: /particle/list).
0334 Currently, it does not work with ions.
0335 The output filename: if users leave this blank then the standard output is used.
0336
0337 Below is an example in order to calculate the stopping power for alphas into Hydrogen between 1 keV to 150 MeV for 15 points:
0338
0339 /parameter/getstopping G4_H 0.001 150 15 alpha
0340
0341 GEANT4 GENERAL PARTICLE SOURCE
0342 ===================================================
0343
0344 The General Particle Source (GPS, G4 class name: G4GeneralParticleSource) is in the current version of 'hadrontherapy': it enables the user to use standard energy, angular and spatial distributions. The GPS also includes methods to bias the sampling distribution.
0345
0346 The G4GeneralParticleSource can be utilized by typing commands from the /gps command directory, or include the /gps commands in a macro file.
0347
0348 RADIOBIOLOGICAL QUANTITIES: DOSE, LET, RBE
0349 ===================================================
0350
0351 LET calculation
0352
0353 'hadrontherapy' application simulates and calculates the averaged LET-dose and LET-track fully accounting for the contribution of secondary particles generated in the target fragmentation
0354 Dependencies as respect to the transport parameters adopted during the Monte Carlo simulations as the production cut of secondaries particles, voxel size and the maximum steps length are minimized in the LET calculation. The first implementation of LET calculation adopted in hadrontherapy is reported in F. Romano et al.,(2014) Phys Med Biol 59(12): 2863–8. Now, in ‘hadrontherapy’ is implemented the approach reported in G. Petringa et al., (2020) Phys Med Bio. (DOI: 10.1088/1361-6560/abaeb9)
0355 At run time, data needed to calculate LET are collected. At the end of simulation, LET mean values are calculated and stored into a file.
0356
0357 The Let.out file will be produced at the end of a run, where you can
0358 find the dose and track average LET for each tracked particles (both primary and
0359 secondary ones) and the total mean LET.
0360
0361 The file is structured as follows:
0362 - The first three columns contain the voxel indexes (first index "i" refers to the beam direction);
0363 - The fourth and fifth columns contain respectively total mean dose LET (LDT) and total mean track LET (LTT)
0364 - The rest of columns contain LET Dose and Track for each single ion (whose name is in the top row of the file).
0365
0366 To activate the LET computation (HadrontherapyLet.cc), you have to execute
0367 the following command:
0368
0369 /analysis/secondary true
0370 /analysis/computeLet
0371
0372 RBE and Survival calculation
0373
0374 A method was developed to assess the biological damages produced by proton and ion beams in terms of survival fraction curves, i.e of the number of cells able to survive after the irradiation at different dose. The approach is based on the combined use of Monte Carlo Geant4 simulations (to calculate the doses deposited and the energy spectra of particles interacting with cells) and of the Survival analytical code (Manganaro L, Russo G, et al. Survival: a simulation toolkit introducing a modular approach for radiobiological evaluations in ion beam therapy. Phys. Med. Biol. 2018;63(8). 08–01).
0375 The Monte Carlo simulations permit the calculation of the Edep and Ekin distributions that, coupled with the radiobiological response model, allow the final and calculation of a survival curve.
0376 The kinetic energy and the LET value of any primary ion and of the secondaries generated in each slice of the simulated water phantom are retrieved at each simulation step. The corresponding values of αi and βi, for each specific ion i with a kinetic energy Ei and a released dose Di, are then calculated by direct linear interpolation of the Look-up-tables provided by the Survival analytical code.
0377 (G.Petringa et al., Physica Medica 58 (2019) 72–80)
0378
0379 The AlphaAndBeta.out and RBE.out files are produced at the end of the run.
0380 AlphaAndBeta.out contains the average alpha (first column) and beta (second column) parameters calculated for each slice (third column).
0381
0382 RBE.out contains the following quantities:
0383 Dose (Gy): the physical dose;
0384 ln(S): the natural log of the Survival Fraction;
0385 Survival Fraction;
0386 DoseB (Gy): the biological dose;
0387 RBE: relative biological effectiveness;
0388 depth (slice): n. of the slice;
0389
0390 To activate the RBE computation (HadrontherapyRBEcc), you have to execute
0391 the following command:
0392
0393 #you can choose the verbosity level
0394 /rbe/verbose 2
0395
0396 #you have to indicate the name of the LUT inside the rbe folder
0397 /rbe/loadLemTable data/rbe/lem.csv
0398
0399 /rbe/calculation 1
0400 /rbe/accumulate 1
0401
0402 #you have to indicate the name of the cell line
0403 /rbe/cellLine ARPE19
0404 /rbe/doseScale 7777770
0405
0406 SIMULATION OUTPUT
0407 ===================================================
0408
0409 Store results in an ASCII file
0410
0411 A .out ASCII file is generated at the end of each run, Dose.out is its default name that can be changed in the HadrontherapyMatrix.cc file.
0412 The file contains four columns; the first three columns represent the voxel indexes (that unequivocally identify the voxel volume), while the last column represents the dose deposited in that given voxel.
0413 Alternatively, users can force the store of data to a given filename, after any BeamOn command and before the program ends, by the macro command /analysis/writeDoseFile <myfile.out>.
0414
0415 Moreover, if the macro command /analysis/secondary <true> is given, before the BeamOn command, ordinated dose and fluence, for every secondary produced, is added to the file.
0416 If the macro command /analysis/computeLet is given, and the ascii file Let.out is written, with the dose and track average LET computations.
0417
0418 Users must take care that any change of the phantom geometry will clear all dose data.
0419
0420 It is also possible to create multiple new output files in the same simulation session. For example:
0421
0422 /beam/energy/meanEnergy 4800 MeV
0423 /analysis/setAnalysisFile firstRun.root
0424 /run/beamOn 1000
0425 /analysis/writeDoseFile firstRun.out # this will write both the .root and the .out file!
0426
0427 /beam/energy/meanEnergy 3000 MeV
0428 /analysis/setAnalysisFile secondRun.root # this
0429 /run/beamOn 1000
0430 /analysis/writeDoseFile secondRun.out
0431
0432 Please contact cirrone@lns.infn.it for more details or suggestions and feedback on this document.
0433
0434