Low Energy Electromagnetic Physics PART II Maria Grazia Pia INFN Genova [email protected] on behalf of the Low Energy Electromagnetic Working Group Geant4 Workshop Helsinki, 30-31 October 2003 http://www.ge.infn.it/geant4/training/ Maria Grazia Pia, INFN Genova 1 Technology transfer Particle physics software aids space and medicine Geant4 is a showcase example of technology transfer from particle physics to other fields such as space and medical science […]. CERN Courier, June 2002 Maria Grazia Pia, INFN Genova 2 Comparison with commercial treatment planning systems Central-Axis depth dose M. C. Lopes IPOFG-CROC Coimbra Oncological Regional Center L. Peralta, P. Rodrigues, A. Trindade LIP - Lisbon CT-simulation with a Rando phantom Experimental data with TLD LiF dosimeter Profile curves at 9.8 cm depth CT images used to define the geometry: PLATO overestimates the dose at ~ 5% level a thorax slice from a Rando anthropomorphic phantom Maria Grazia Pia, INFN Genova 3 Brachytherapy Courtesy of R. Taschereau, UCSF Flexibility of modeling geometries and materials Radioactive Decay Module Low energy electromagnetic processes Interactive facilities: visualisation, analysis, UI Maria Grazia Pia, INFN Genova 4 Dosimetry Simulation of energy deposit through Geant4 Low Energy Electromagnetic package to obtain accurate dose distribution 2-D histogram with energy deposit in the plane containing the source Production threshold: 100 mm Analysis of the energy deposit in the phantom resulting from the simulation Dose distribution Isodose curves AIDA + Anaphe Python for analysis for interactivity may be any other AIDA-compliant analysis system Maria Grazia Pia, INFN Genova 5 Endocavitary brachytherapy S. Agostinelli, F. Foppiano, S. Garelli, M. Tropeano 40 Cut 0.1mm 30 200% 150% 100% 75% 50% 25% Distanza lungo Z (mm) 20 10 0 -10 -20 -30 Role of the simulation: precise evaluation of the effects of source anisotropy -40 -40 -30 -20 -10 0 10 20 30 Longitudinal axis of the source 40 Distanza lungo X (mm) Transverse axis of the source Difficult to make direct measurements rely on simulation for better accuracy than Comparison with experimental data validation of the software conventional treatment planning software Simulation Simulazioni Plato Plato Data Misure 2,5 Effects of source anisotropy 2,5 Simulazioni Simulation Plato Plato 2,0 Dose % Dose % 2,0 1,5 1,0 1,5 1,0 0,5 0,5 0,0 0,0 -40 -30 -20 -10 0 10 20 Distanza lungo X (mm) Maria Grazia Pia, INFN Genova Distance along X (mm) 30 40 -40 -30 -20 -10 0 10 Distanza lungo Z (mm) 20 6 Distance along Z (mm) 30 40 Simulation Simulazione Nucletron Nucletron Data Misure 1,2 Superficial Brachytherapy 1,0 F. Foppiano, M. Tropeano Experimental validation: Geant4 Nucletron data IST data Dose % 0,8 0,6 0,4 0,2 Leipzig applicators 0,0 0 10 20 30 Distance along Z (mm) Distanza lungo Z (mm) Code reuse: still the same application as in the previous case only difference: the implementation of the geometry of the applicator, derived from the same abstract class No commercial software exists for superficial brachytherapy treatment planning! Maria Grazia Pia, INFN Genova 7 40 50 Dosimetry Endocavitary brachytherapy MicroSelectron-HDR source Dosimetry Superficial brachytherapy Leipzig applicator Maria Grazia Pia, INFN Genova 8 Dosimetry Interstitial brachytherapy Bebig Isoseed I-125 source 0.16 mGy =100% Isodose curves Maria Grazia Pia, INFN Genova 9 RBE enhancement of a 125I brachytherapy seed with characteristic X-rays from its constitutive materials Goal: improve the biological effectiveness of titanium encapsulated 125I sources in permanent prostate implants by exploiting X-ray fluorescence Titanium shell (50 µm) 1.08 1.08 Mo- Y 1.06 1.06 M200 M200 1.04 1.04 1.02 1.02 Silver core (250 µm) ++ tumors 11 00 11 -- healthy tissues 22 33 44 55 4.5 mm Distance away from seed All the seed configurations modeled and simulated with Maria Grazia Pia, INFN Genova R. Taschereau, R. Roy, J. Pouliot Centre Hospitalier Universitaire de Québec, Dépt. de radio-oncologie, Canada Univ. Laval, Dépt. de Physique, Canada Univ. of California, San Francisco, Dept. of10Radiation oncology, USA Hadron Therapy Medical Applications G.A. Pablo Cirrone On behalf of the CATANA – GEANT4 Collaboration Qualified Medical Physicist and PhD Student 11 University of Catania and Laboratori Nazionali del Sud - INFN, Italy Maria Grazia Pia, INFN Genova Modulator & Range shifter Ligth field Laser Maria Grazia Pia, INFN Genova Scattering system Monitor chambers CATANA hadrontherapy facility 12 Real hadron-therapy beam line GEANT4 simulation Maria Grazia Pia, INFN Genova 13 Hadrontherapy: comparison of physics models to data Standard Processes Standard + hadronic Low Energy Low Energy + hadronic Maria Grazia Pia, INFN Genova 14 Beam Line Validation LowE e.m. + hadronic (precompound) Difference below 3% even on the peak Maria Grazia Pia, INFN Genova 15 Lateral Dose Validation Difference in penumbra = 0.5 % Difference in FWHM = 0.5 % Difference Max in the homogeneity region = 2 % Maria Grazia Pia, INFN Genova 16 Simulation of cellular irradiation with the CENBG microbeam line using GEANT4 Sébastien Incerti representing the efforts of the Interface Physics - Biology group Centre d'Etudes Nucléaires de Bordeaux - Gradignan IN2P3/CNRS Université Bordeaux 1 33175 Gradignan France Email : [email protected] Nuclear Science Symposium Portland, OR, USA October 19-25th, 2003 Maria Grazia Pia, INFN Genova 17 Need for a reliable simulation tool WHY A SIMULATION TOOL ? Technical challenge : to deliver the beam ion by ion, in air, keeping a spatial resolution compatible with irradiation at the cell level, i.e. below 10 µm A simulation tool will help to : • understand and reduce scattering along the beam line as much as possible : collimator, diaphragm, residual beam pipe pressure… • understand and reduce scattering inside the irradiation chamber : single ion detector, beam extraction into air, cell culture layer… • predict ion transport (ray tracing) in the beam line magnetic elements • dosimetry with high flexibility and integration. Maria Grazia Pia, INFN Genova GEANT4 18 Reference Testing GEANT4 at the micrometer scale Simulation of ion propagation in the CENBG microbeam line using GEANT4, S. Incerti et al., Nucl. Instr. And Meth. B 210 (2003) 92-97 ALPHAS PROTONS • • horizontal error bars : 5% experimental uncertainty on the foil thickness value vertical error bars combine statistical fluctuations obtained by varying the number of incident particles in the simulation and systematic fluctuations of the FWMH values due to the 5 % error on the foil thickness ; they range from 1% to 4% for protons and from 5% to 7% for alphas. • • ICRU_R49p and ICRU_R49He electronic stopping power tables used (G4hLowEnergyIonisation) Important issue on cuts : - Default cutValue in PhysicsList.cc : 100 µm and above - Max step length in target foil logic volume (UserLimits) in DetectorConstruction.cc : foil thickness / 10 - low energy EM and standard packages give same results in the measured region of thickness Maria Grazia Pia, INFN Genova 19 Beam on target cells AIR AIR • Beam initial energy distribution : VACUUM 1 mm 10 µm T ± s T = 3.00 MeV ± 0.06 keV In red : scattered by • Beam energy distribution on target : diaphragm T ± s T = 2.37 ± 0.01 MeV In blue : no scattering pexp » 80 - 90% Probability to reach a given 10 µm circular surface : • In vacuum : pa ± s p = ( 99.41 ± 0.05)% • Taking into account the residual air ( 5.10-6 mbar ) :pa ± s p = (70.5 ± 0.8)% a a Maria Grazia Pia, INFN Genova 20 GATE, a Geant4 based simulation platform, designed for PET and SPECT For the OpenGATE collaboration: Steven Staelens Maria Grazia Pia, INFN Genova 21 Overview Geometry: +sources Interface with the user scanners : scripting (macros) Maria Grazia Pia, INFN Genova 22 low energy e/g extensions Cosmic rays, jovian electrons were triggered by astrophysics requirements X-Ray Surveys of Planets, Asteroids and Moons Solar X-rays, e, p Courtesy SOHO EIT Geant3.21 Induced X-ray line emission: indicator of target composition (~100 mm surface layer) ITS3.0, EGS4 Geant4 C, N, O line emissions included Maria Grazia Pia, INFN Genova 23 Courtesy ESA Space Environment & Effects Analysis Section X-ray fluorescence, PIXE ESA Bepi Colombo mission to Mercury Analysis of the elemental composition of Mercury crust through X-ray spectroscopy Fluorescent spectrum of Icelandic Basalt (“Mars-like”) Experimental data: 6.5 keV photon beam, BESSY Courtesy of A. Owens et al., ESA Maria Grazia Pia, INFN Genova many more new features, no 24 time to mention them all... LowE at very high energy... Fluorescence is an important effect in the simulation of ultra-high energy cosmic ray experiments Courtesy of Auger Maria Grazia Pia, INFN Genova 25 Geant4 simulation of test-mass charging in the LISA mission Very long base-line: 1 million km Very high precision: < 1nm – 1pm (!) Maria Grazia Pia, INFN Genova 26 Physics List EM processes (LowE) Electrons, Gammas, etc Atomic de-excitation Hadrons (no hFluorescence) Secondaries Cuts: (250 eV), 1mm - 5mm Kill e- outside caging Maria Grazia Pia, INFN Genova 27 Underground astroparticle experiments Courtesy of Borexino Gran Sasso Laboratory, Italy unique simulation capabilities: lowE physics fluorescence radioactivity neutrons etc.. Maria Grazia Pia, INFN Genova 28 Credit: O. Cremonesi, INFN Milano Boulby Mine dark matter search Prototype Simulation Courtesy H. Araujo and A. Howard, IC London ZEPLIN III One High Energy event mirror LXe GXe PMT Maria Grazia Pia, INFN Genova 29 source ...and much more No time to show all applications Very good relationship between Geant4 LowE Group and its user community – valuable feedback on applications – new user requirements to extend and improve the package Feel free to contact us! Many user applications become (simplified) advanced examples distributed with Geant4 – to help other groups in the user community to get started Maria Grazia Pia, INFN Genova 30