Application examples for Space, Medicine, Biology Sébastien Incerti On behalf of the Geant4 collaboration

Content Medical Radiobiology Space Ray-tracing

Medical

GATE http://opengate-redesign.healthgrid.org/

GEANT4 based proton dose calculation in a clinical environment: technical aspects, strategies and challenges H. Paganetti’s conclusions (Bordeaux, Nov 2005): Routine use of (proton) Monte Carlo dose calculation (using GEANT4) requires work in many different areas of treatment head and patient modeling requires establishing a link between treatment planning and Monte Carlo is being done at MGH Harald Paganetti

gMocren KEK

LIP Comparison with commercial treatment planning systems M. C. Lopes 1, L. Peralta 2, P. Rodrigues 2, A. Trindade 2 1 IPOFG-CROC Coimbra Oncological Regional Center - 2 LIP - Lisbon CT-simulation with a Rando phantom Experimental data obtained with TLD LiF dosimeter CT images used to define the geometry: a thorax slice from a Rando anthropomorphic phantom Agreement better than 2% between GEANT4 and TLD dosimeters LIP

Hadrontherapy KEK

Physics settings for using the Geant4 toolkit in proton therapy C Physics settings for using the Geant4 toolkit in proton therapy C. Zacharatou Jarlskog, H. Paganetti, IEEE TNS 55 (2008) 1018 - 1025 Comparison of measured (squares) and simulated (histograms) longitudinal charge distributions in the Faraday cup for four combinations of EM physics (Standard or Low Energy) and models for p and n inelastic scattering (Bertini or binary cascade). The horizontal axes show the charge collector (‘channel’) number (with increasing depth) in the Faraday cup. The vertical axes show the collected charge normalized to the number of protons in the beam (160 MeV). View of he Faraday cup consisting of 66 absorbers (CH2) interspaced by charge collectors (brass)

Assessment of organ-specific neutron equivalent doses in proton therapy using computational whole-body age-dependent voxel phantoms C. Zacharatou Jarlskog et al, Phys. Med. Biol. 53 (2008) 693–717 Organ equivalent dose as a function of phantom age averaged over eight proton fields treating a lesion In the brain kidneys (circles) small intestine (squares) bladder (triangles) Organ equivalent dose as a function of distance to organs segmented in the adult phantom for eight proton fields. The distance (in cm) is based on the distance between the center of the brain (target) and the approximate center position of the organ.

LOW DOSE RATE BRACHYTHERAPY contact e-mail: anatoly@uow.edu.au I-125 seed migrated to the vertebral venous plexus – what effect does the bone have? Dose to bone ~100% greater when simulated as being bone.

MRI-LINAC HYBRID SYSTEMS contact e-mail: anatoly@uow.edu.au ERE – the Electron Return Effect (exiting electrons return to patient increasing exit dose) 6MV beam 10x10 cm 30x30x20 cm phantom Transverse B-field electron paths shown only 10 micron thick voxels up to 100% increase (0.2 T) lower B-fields cause the largest increase

PROTON COMPUTED TOMOGRAPHY contact e-mail: anatoly@uow.edu.au Monoenergetic transmission proton beam Silicon strip detectors, record proton position and direction Human head phantom Scintillator crystal to record proton energy loss

PROTON COMPUTED TOMOGRAPHY Digital Phantom Reconstructed Image

PROTON THERAPY BEAM VERIFICATION 511keV g’s generated by b+ annihilation Full energy collection in scintillator crystal Use pCT detector modules as Compton Camera to record b+ activity distribution generated by proton treatment beam Compton scatter in Si planes If feasible, pCT detectors will provide complete planning and verification tool!

VALIDATION: OCULAR BRACHYTHERAPY Contact e-mail: maigne@clermont.in2p3.fr

TURIN UNIVERSIY AND INFN, ITALY contact e-mail: bourhale@to.infn.it INFN section of Turin (F Bourhaleb. A. Attili, F. Marchetto, I. Cornelius, I. Rinaldi, V. Monaco) Simulation of proton and Carbon ion beams interactions with water phantoms study of fragmentation products simulation of on line devices for measures of delivered dose to the patient study of radiobiological effects for carbon ion beams

PISA UNIVERSIY AND INFN, ITALY contact e-mail: valeria. rosso@pi. infn PISA UNIVERSIY AND INFN, ITALY contact e-mail: valeria.rosso@pi.infn.it INFB section of Pisa (F. Attanasi, N. Belcari, M. Camarda, A. Del Guerra, N. Lanconelli, V. Rosso , S. Vecchio) DOPET project: proton therapy monitoring device geant4 Monte Carlo simulation of the prototype, composed by two planar active heads comparisons with experimental data from CATANA beam line at LNS – INFN, Catania (70 MeV proton beam on PMMA phantom)

Radiobiology

Geant4 DNA Geant4 is currently being extended and improved for microdosimetry applications et the eV scale : the Geant4 DNA project Expected developments include : Physics : complementary/additional theoretical models, for other target materials (DNA, Silicon,…), merging with standard EM Physics design Physico-chemical and chemistry for the production of radical species Geometry : atomistic approach (Protein Data Bank), voxellized approach Biological damage stage, benefiting from experimental validation (ex. microbeam cellular irradiation at CENBG) New examples will be delivered for Geant users Cellular phantoms DNA molecule Biological damages (DSB)

Nanodosimetric modelling of low energy electrons in a magnetic field Purpose : investigate possible biological effect enhancement of low energy electrons in a magnetic field Simulated setup Two target geometries : DNA-segment : represented by water cylinder of diameter 2.3 nm and height 3.4 nm Nucleosome : represented by water cylinder of diameter 6 nm and height 10 nm Incident particle : 50 eV – 10 keV electrons Magnetic field : 1-10 T Physics processes : Geant4 DNA Comparison between Geant4 and PTB code (B. Grosswendt et al., PTB Braunschweig) Kindly provided by Marion Bug & Anatoly Rosenfeld Centre for Medical Radiation Physics University of Wollongong, Australia Presented at the 13th Geant4 collaboration workshop

Comparison of cluster-size distribution Good agreement between the two codes for both volumes PTB-code shows lower mean cluster-size for electrons < 1 keV (left) Confirmed in probability distribution (right): higher number of large cluster-sizes produced in G4-code than in PTB-code Due to different cross-sections, statistical error (?) RBE enhancement in magnetic field under investigation Probability VS cluster size Cluster size VS Energy A cluster size is the number of ionisations in the volume, resulting from one track. Multiple tracks lead to a distribution of cluster sizes, which follows Poisson's law for small volumes. From this frequency distribution I calculated the probability distribution. The first moment of the probability distribution gives the mean cluster size. Mean ionisation cluster-size vs. electron energy, comparison of our data (G4) with the MC-code from PTB Probability of cluster size. Comparison of G4-code (solid lines) with MC-code from PTB (dashed lines)

Predicting cell lesions Kindly provided by Djamel Dabli & Gérard Montarou Laboratoire de Physique Corpusculaire Université Blaise Pascal, IN2P3/CNRS, Aubière, France Predicting cell lesions The mean number of lethal lesions in a biological nucleus can be expressed with a linear quadratic formula (Kellerer et al. 1978) sub-lesions can combine in pairs to induce lethal lesions t(x) is the is the physical proximity function, representing the probability distribution of all distances between pairwise energy transfer points in the track g(x) is the biological proximity function representing the distribution of sensitives sites in a nucleus. t(x) can be calculated from Geant4 electromagnetic interactions (Standard, Low Energy, Geant4 DNA) in liquid water

Proximity functions good agreement between Dabli’s and Montarou’s results with Geant4DNA physics models and the estimation of Chen and Kellerer (2006). Proximity function

Cellular irradiation @ CENBG 1 2 3 Cytoplasm Confocal microscopy of HaCat cell Cellular irradiation 3 MeV alphas Ion beam analysis with protons (PIXE, RBS) 3 Nucleus 1 2 3D high resolution phantom a b Microdosimetry Geant4 Chemical composition Mean dose in nucleus (Gy) Liquid water 0.14 ± 0.02 Reference cell (ICRU) 0.32 ± 0.06 CENBG measurements 0.38 ± 0.07 c d

Space science

X-ray Multi-Mirror mission (XMM) Launch December 1999 Perigee 7000 km apogee 114000 km Flight through the radiation belts Telescope tube X-ray detectors (CCDs) Mirrors Chandra X-ray observatory, with similar orbit, experienced unexpected degradation of CCDs Possible effects on XMM? Baffles

g astrophysics FGST AGILE g-ray bursts FGST GLAST AGILE Typical telescope: Tracker Calorimeter Anticoincidence g conversion electron interactions multiple scattering d-ray production charged particle tracking

MAXI ISS Columbus AMS EUSO Bepi Colombo SWIFT LISA Smart-2 ACE INTEGRAL Astro-E2 JWST GAIA Herschel Cassini FGST XMM-Newton

ISS Courtesy T. Ersmark, KTH Stockholm

X-Ray Surveys of Asteroids and Moons ESA Space Environment & Effects Analysis Section Cosmic rays, jovian electrons X-Ray Surveys of Asteroids and Moons Solar X-rays, e, p Geant3.21 G4 “standard” Courtesy SOHO EIT Geant4 low-E Induced X-ray line emission: indicator of target composition (~100 mm surface layer) C, N, O line emissions included

Bepi Colombo: X-Ray Mineralogical Survey of Mercury Space Environments and Effects Section Bepi Colombo: X-Ray Mineralogical Survey of Mercury Alfonso Mantero, Thesis, Univ. Genova, 2002 BepiColombo ESA cornerstone mission to Mercury Courtesy of ESA Astrophysics

PLANETOCOSMICS by L. Desorgher et al. Planets Planetary radiation environments PLANETOCOSMICS by L. Desorgher et al. L. Desorgher, Bern U.

Radiation damage

X- and Gamma-ray astronomy “Suzaku” Observatory (ISAS/JAXA and many universities) The 5th Japanese X-ray astronomy satellite Launched on 2005-07-10 High-precision and Low-noise detector systems XIS (X-ray CCD camera) [0.3—12 keV] HXD (Hard X-ray Detector) [10—600 keV] 35

Background-event spectrum of XIS Physics processes Electromagnetic Interaction (down to 250eV) Hadronic Interaction Primary events from 4p Sr Used Geant4 outputs: Physics process of particle generation, position, energy, solid-ID Energy deposition and its physics process ParentID、TrackID、 StepNumber Geant4 simulation (energy deposition) + charge-diffusion simulation in CCD Succeeded in representing the BGD spectrum and resolving the BGD generation mechanism 36

Suzaku Hard X-ray Detector (HXD) 　PIN*64 BGO GSO*16 (10～60keV) (30～600keV) Si-PIN [2mm thick](10—60 keV) GSO [5mm thick](30—600keV) BGO: Shield + Phoswitch BGO well + Fine Collimator: narrow FOV as a non-imaging detector -> Low Background -> High Sensitivity Complex Response for incident photons Performance Key: Monte Carlo simulator 13th Geant4 Workshop 5th Space Users' Workshop and Japan's activity (2008-10-07) 37

ESA / space resources http://geant4.esa.int/ GRAS PLANETOCOSMICS MULASSIS SPENVIS SSAT GEMAT… ESA / space resources http://geant4.esa.int/

Ray tracing

Geant4 for beam transportation Courtesy of V.D.Elvira (FNAL)

Courtesy of G.Blair (CERN)

Sub-micron raytracing @ CENBG : nanobeam line design 3D field map OM50 quadrupoles DOUBLET TRIPLET Electrostatic deflection 4565 5100 Diaphragm Diaphragm Object collimator 3150 400 40 40 400 250 X Image plan Switching magnet 90° analysis magnet 300 100 100 11° 90° Singletron incident beam Intermediate image 60 nm x 80 nm Image < 50 nm FWHM same prediction as Oxray, Zgoubi… Object 5 µm in diameter

G4BeamLine http://www.muonsinc.com

Where to find information Geant4 novice/extended/advanced examples : http://cern.ch/geant4 Space resources at ESA : http://geant4.esa.int GATE/ThIS : http://opengate-redesign.healthgrid.org/ G4beamline : http://www.muonsinc.com More applications presented during Geant4 workshops

ATLAS, CMS, LHCb, ALICE @ CERN BaBar, ILC… Brachytherapy PET Scan (GATE) Hadrontherapy DICOM dosimetry Medical linac Earth magnetosphere ISS GAIA FGST Physics-Biology