ooad… lowe electrons from hep computing to medical research and vice versa bidirectional from hep...
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OOAD… OOAD…
LowE Electrons
From HEP computing to medical research From HEP computing to medical research and vice versaand vice versa
BidirectionalBidirectional Technology transfer and application results
HEP world offers advanced software technologies to medical physics worldMedical physics turns in back feedback on the developed tools
Globalisation : sharing functionalities across diverse field
GEANT4 LOW ENERGY ELECTROMAGNETIC PHYSICS
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User Requirements Document Status: in CVS repository
Version: 2.4 Project: Geant4-LowE Reference: LowE-URD-V2.4 Created: 22 June 1999 Last modified: 26 March 2001 Prepared by: Petteri Nieminen (ESA) and Maria Grazia Pia (INFN)
UR 2.1The user shall be able to simulate electromagnetic interactions of positive charged hadrons down to < 1KeV. Need: Essential Priority: Required by end 1999 Stability: T. b. d. Source: Medical physics groups, PIXE Clarity: Clear Verifiability: Verified
Requirements for Geant4 LowEnergy package
Low Energy Processes for e-, hadrons,ions, gamma
Energy range: 250 eV up to 100 GeV
Based on EPDL97, EEDL and EADL evaluated data libraries cross sections sampling of the final state
Software architecture
LowE Hadrons and ions
What in a simulation software system is relevant to the
bio-medical community?
Use of evaluated data libraries
The transparency of physics Advanced functionalities in geometry, physics, visualisation etc.
Extensibility to accomodate new user requirements (thanks to the OO technology)
Adoption of standards wherever available (de jure or de facto)
Quality Assurance based on sound software engineering
Independent validation by a large user community
worldwide
User support from expertsA rigorous
software process
Specific facilities controlled by a friendly UI
•The transparency of the physics implementation is fundamental for “sensitive”
and critical applications, such as medical ones
Validation of Geant4 LowEnergy package Geant4 simulation results are compared to procol data (i.e. NIST) and/or to experimental data
The first user application … …. and the same requirements in HEP too
Seedcomponents
Silver core (250 µm)
Titanium shell (50 µm)
Iodine-125 seed
4.5 mm
Distance (nm)
10 keV electron in water
R. Taschereau, R. Roy, J. Pouliot
Centre Hospitalier Universitaire de Quebec, Dept. de radio
-oncologie, Canada Univ. Laval, Dept. de Physique, Canada
Univ. of California, San Francisco, Dept. of Radiation Oncology, USA
Exploiting X-ray fluorescence to lower
the energy spectrum of photons (and electrons)
and enhance the RBE
Similar requirements on both low energy e/gamma and hadrons, K-shell transitions etc.from “underground” HEP experiments collected ~1 year later Recent interest on these physics models from LHC for precision detector simulationThey profit of the fact that the code does already exist, has been extensively tested
and experimentally validated by other groups
HEP offers methodologies and tools
“It was noted that experiments have requirements for independent, alternative physics models. In Geant4 these models, differently from the concept of packages, allow the user to understand how the results are produced, and hence improve the physics validation. Geant4 is developed with a modular architecture and is the ideal framework where existing components are integrated and new models continue to be developed.”
Domain decomposition
Geant4 architecture
Uni-directional flow of dependencies
Software Engineering
plays a fundamental role in Geant4
User Requirements• formally collected• systematically updated• PSS-05 standard
Software Process• spiral iterative approach• regular assessments and improvements• monitored following the ISO 15504 model
Quality Assurance• commercial tools• code inspections• automatic checks of coding guidelines• testing procedures at unit and integration level• dedicated testing team
Object Oriented methods•OOAD• use of CASE tools
• essential for distributed parallel development• contribute to the transparency of physics
Use of Standards • de jure and de facto
ApplicationsIn Medical Physics
Verification of conventional radiotherapy treatment planning (as required by protocols)
Investigation of innovative methods in radiotherapy Radiodiagnostics
Brachytherapy
Dose distribution onplains at differentdistances from the source
Protontherapy
New projectsHadrontherapy studies In vivo dosimetry(mammography, colonscopy), Superposition and fusion of anatomic
and functional images PET Intra-operatory radiotherapy CT interfaceGEANT4- DNA
Study of radiation damage at the cellular and DNA level in the space radiation environment(and other applications,not only in the space domain)
Relevance for space: astronaut and airline
pilotradiation hazards, biological experiments
Applications in radiotherapy, radiobiology...