Transcript Geant4, EPS

From HEP computing to
bio-medical research
and vice versa
Technology transfer and
application results
S. Chauvie, G. Cosmo, F. Foppiano, E. Lamanna, F. Marchetto, P. Nieminen,
M.G. Pia, A. Solano, M. Tropeano
CERN - ESA - INFN (Cosenza, Genova, Torino) - IST Natl. Inst. Cancer Research (Genova)
…with contributions from many
CHEP 2001 Conference
Beijing, 3-7 September 2001
Maria Grazia Pia, INFN Genova - CHEP 2001
users
Globalisation
Sharing requirements and functionalities
across diverse fields
Maria Grazia Pia, INFN Genova - CHEP 2001
Requirements for LowE p in
G E A N T 4 L O W E N E R G Y E L E C T R O M A G N E T IC P H Y S IC S
GEANT4 LOW ENERGY
E L E C T R O M A G N E T IC P H Y S IC S
UR 2.1
The user shall be
able to simulate electromagnetic
interactions of positive charged
hadrons down to < 1 KeV.
Need: Essential
Priority: Required by end 1999
Stability: T. b. d.
U ser R equirem en ts D o cum en t
Source: Medical physics groups, PIXE
Clarity: Clear
S ta tu s :
in C V S rep o sito ry
Verifiability: Verified
V ersion: 2.4
P roject: G eant4 -L ow E
R eferen ce: L ow E -U R D -V 2.4
C reated : 22 June 1999
L ast m od ified : 26 M arch 2001
P rep ared b y: P etteri N iem inen (E S A ) and M aria G razia P ia (IN F N )
Maria Grazia Pia, INFN Genova - CHEP 2001
LowE Hadrons and ions
OOAD…
Maria Grazia Pia, INFN Genova - CHEP 2001
…and validation
Experimental data:
Bragg peak
Test set-up at PSI
• data
O
simulation
INFN-Torino medical
physics group
Courtesy of R. Gotta,
Thesis
Maria Grazia Pia, INFN Genova - CHEP 2001
Geant4 LowE Working Group
Chandra X-ray Observatory
Status Update
September 14, 1999
MSFC/CXC
CHANDRA CONTINUES TO TAKE SHARPEST IMAGES
EVER; TEAM STUDIES INSTRUMENT DETECTOR
CONCERN
Normally every complex space facility encounters a
few problems during its checkout period; even
though Chandra’s has gone very smoothly, the
science and engineering team is working a concern
with a portion of one science instrument.
The team is investigating a reduction in the energy
resolution of one of two sets of X-ray detectors in the
Advanced Charge-coupled Device Imaging
Spectrometer (ACIS) science instrument.
A series of diagnostic activities to characterize the
degradation, identify possible causes, and test
potential remedial procedures is underway.
The degradation appeared in the front-side
illuminated Charge-Coupled Device (CCD) chips of
the ACIS. The instrument’s back-side illuminated
chips have shown no reduction in capability and
continue to perform flawlessly.
Maria Grazia Pia, INFN Genova - CHEP 2001
What could be the source of
detector damage?
Radiation belt electrons?
Scattered in the mirror shells?
Effectiveness of magnetic “brooms”?
Electron damage mechanism? - NIEL?
Other particles? Protons, cosmics?
Courtesy of R. Nartallo, ESA
XMM-Newton
CCD displacement damage: front
vs. back-illuminated.
30 mm Si  ~1.5 MeV protons
2 mm
30 mm
30 mm
2 mm
Active layer
Passive layer
“Electron
deflector”
V a ria tio n in E fficien cy w ith P ro to n E n erg y a t v a rio u s so u rce h a lf-a n g les
1 .E -0 4
E P IC 0 .5 d eg
1 .E -0 5
EPIC
E P IC 1 d eg
E P IC 4 d eg
E ffic ie nc y
E P IC 2 d eg
Courtesy of
ESA Space Environment &
Effects Analysis Section
1 .E -0 6
E P IC 1 0 d eg
E P IC 3 0 d eg
RGS
R G S 0 .5 d eg
R G S 1 d eg
1 .E -0 7
R G S 2 d eg
R G S 4 d eg
R G S 1 0 d eg
1 .E -0 8
R G S 3 0 d eg
1 .E -0 9
0 .0
0 .5
1 .0
1 .5
2 .0
2 .5
3 .0
3 .5
P ro to n E n erg y (M eV )
Low-E (~100 keV to few MeV), low-angle (~0°-5°) proton scattering
Maria Grazia Pia, INFN Genova - CHEP 2001
What happened next?
XMM was launched on
10 December 1999 from Kourou
Courtesy of
Maria Grazia Pia, INFN Genova - CHEP 2001
EPIC image of the two flaring Castor
components and the brighter YY Gem
…and the other way round
Maria Grazia Pia, INFN Genova - CHEP 2001
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
Geant3.21
ITS3.0, EGS4
Courtesy SOHO EIT
Induced X-ray line emission:
indicator of target composition
(~100 mm surface layer)
Maria Grazia Pia, INFN Genova - CHEP 2001
Geant4
C, N, O line emissions included
Courtesy ESA Space Environment & Effects Analysis Section
Low Energy Processes: e, g
Fe lines
GaAs lines
250 eV up to 100 GeV
Based on EPDL97, EEDL and EADL
evaluated data libraries
- cross sections
- sampling of the final state
Maria Grazia Pia, INFN Genova - CHEP 2001
Scattered
photons
Photon attenuation:
vs. NIST data
Testing and Validation by IST - Natl. Inst. for Cancer Research, Genova
1000
N IS T
Geant4 LowEn
NIST
Geant4 LowEn
NIST
G e a n t4 L o w E n
10
water
1
Pb
Fe
m/r (cm 2 / g in lead
m /r (cm 2 /g) in iron
m / r (cm 2 /g ) in w a te r
100
100
10
1
10
1
0.1
0 .1
0.1
0.01
0 .0 1
0 .1
1
0.01
10
0.01
0.01
P h o to n E n e rg y (M e V )
14
12
10
8
6
2
0
E (%)
D e lta (% )
4
-2
-4
-6
-8
-1 0
-1 2
-1 4
-1 6
0 .1
10
1
10
P h o to n E n e rg y (M e V )
Maria Grazia Pia, INFN Genova - CHEP 2001
E = (NIST-G4EMStandard)/NIST
E = (NIST-G4LowEn)/NIST
18
16
14
12
10
8
6
4
2
0
-2
-4
-6
-8
-10
-12
-14
-16
-18
0.1
1
Photon energy (MeV)
E = (NIST - G4EM Standard)/NIST
E = (NIST- G4LowEn)/NIST
10
8
6
4
2
E (%)
D e lta = (N IS T -G 4 L o w E n ) / N IS T
0 .0 1
1
Photon Energy (MeV)
D e lta = (N IS T -G 4 E M S ta n d ) / N IS T
16
0.1
0
-2
-4
-6
-8
-10
0.01
0.01
0.1
Photon Energy (MeV)
1
10
0.1
1
Photon Energy (MeV)
Courtesy of S. Agostinelli, R. Corvo, F. Foppiano, S. Garelli, G. Sanguineti, M. Tropeano
…the first user application
Titanium encapsulated 125I
sources in permanent
prostate implants
Seed
c o m p o n e n ts
Exploiting X-ray fluorescence
to lower the energy spectrum
of photons (and electrons) and
enhance the RBE
T ita n iu m sh e ll (5 0 µ m )
10 keV electron in water
4 .5 m m
S ilv e r co re (2 5 0 µ m )
GEANT4
Io d in e -1 2 5 se e d
R. Taschereau, R. Roy, J. Pouliot
Centre Hospitalier Universitaire de Quebec,
Dept. de radio-oncologie, Canada
keV/µm
Terrisol
Univ. Laval, Dept. de Physique, Canada
Univ. of California, San Francisco, Dept. of
Radiation Oncology, USA
Maria Grazia Pia, INFN Genova - CHEP 2001
Distance (nm)
…and the same requirements in HEP too
Similar requirements on both low energy e/g 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 simulation
They profit of the fact that the code
- does already exist,
- has been extensively tested
- and experimentally validated by other groups
Maria Grazia Pia, INFN Genova - CHEP 2001
A lesson to learn
Open mind…
What may look far from the
scope of HEP today,
may be required as an
essential functionality
tomorrow
Maria Grazia Pia, INFN Genova - CHEP 2001
What we can sell
Tools
Methodologies
Maria Grazia Pia, INFN Genova - CHEP 2001
Advanced functionalities
in geometry, physics, visualisation etc.
Extensibility to
accomodate new user
requirements (thanks
to the OO technology)
The transparency of
physics
A rigorous
software process
What in a
simulation
software system
is relevant to the
bio-medical
community?
Use of evaluated
data libraries
Adoption of standards wherever available
(de jure or de facto)
Maria Grazia Pia, INFN Genova - CHEP 2001
Specific facilities
controlled by a friendly UI
Quality Assurance
based on sound
software engineering
Independent validation
by a large user
community worldwide
User support
from experts
shell effects
Physics
requirements
Many new physics
features w.r.t. Geant3
e,g down to 250 eV
(EGS4, ITS to 1 keV, Geant3 to 10 keV)
Based on EPDL97, EEDL and
EADL evaluated data libraries
Fundamental also to
HEP/astroparticle
experiments
Bragg peak
Hadron and ion
electromagnetic models
based on Ziegler and ICRU
New multiple scattering model data and parameterisations
And much more:
fluorescence
radioactive decay
hadronic models
etc…
And many relevant
functionalities in other
domains too, not only physics!
Maria Grazia Pia, INFN Genova - CHEP 2001
Geant4
Geant3
data
ions
Guidelines for physics
From the Minutes of LCB (LHCC Computing Board) meeting on 21 October, 1997:
“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.”
Physics open to evolution
with attention to UR
facilitated by the OO technology
The transparency of the physics implementation:
fundamental for “sensitive”applications, such as medical ones
Maria Grazia Pia, INFN Genova - CHEP 2001
Geant4 architecture
Software Engineering
plays a fundamental role in Geant4
Domain
decomposition
User Requirements
• formally collected
• systematically updated
• PSS-05 standard
Software Process
hierarchical • spiral iterative approach
structure of • regular assessments and improvements
• monitored following the ISO 15504 model
sub-domains
• OOAD
Object Oriented methods • use of CASE tools
• essential for distributed parallel development
Uni-directional
flow of • contribute to the transparency of physics
dependencies
• commercial tools
Quality Assurance
• code inspections
• automatic checks of coding guidelines
• testing procedures at unit and integration level
• dedicated testing team
Use of Standards
Maria Grazia Pia, INFN Genova - CHEP 2001
• de jure and de facto
Applications
Verification of conventional
radioherapy treatment planning
(as required by protocols)
Investigation of innovative methods in radiotherapy
Radiodiagnostics
Maria Grazia Pia, INFN Genova - CHEP 2001
Brachytherapy
Brachytherapy is a medical
therapy used for cancer treatment
Radioactive sources are used to
deposit therapeutic doses near
tumors, while preserving
surrounding healthy tissues
Strict protocols
5 .0 m m
0 .6 m m
1 .1 m m
The IST group follows the
direction of Basic
Dosimetry on Radiotherapy
with Brachytherapy Source
of the Italian Association of
Biomedical Physics (AIFB)
3 .5 m m
3 m m ste e l c a b le
Ac tive Ir-1 9 2 C o re
Maria Grazia Pia, INFN Genova - CHEP 2001
Protocols require testing the
treatment planning systems
Superficial brachytherapy
1,2
Brachytherapy at the
1,0
Natl. Inst. for Cancer
Research (IST-Genova)
Simulation
Simulazione
Nucletron
Nucletron
Data
Misure
Leipzig
applicators
Dose %
0,8
Experimental validation
0,6
0,4
0,2
0,0
0
10
20
30
40
50
Distance
along
Z (mm)
Distanza
lungo
Z (mm)
Distanza
trasversale
(mm)
Transverse
distance
(mm)
-40
-30
-20
-10
0
10
20
30
40
0
-5
-10
Profondità
(mm)
Depth (mm)
-15
-20
-25
-30
80%
60%
40%
20%
10%
-35
-40
-45
-50
-55
-60
Maria Grazia Pia, INFN Genova - CHEP 2001
Courtesy F. Foppiano, M. Tropeano
Endocavitary
brachytherapy
Especially for uterus, vagina
and lung cancer
Source anisotropy
Treatment planning systems
include algorithms to account
for source anisotropy
Maria Grazia Pia, INFN Genova - CHEP 2001
Role of the simulation:
Longitudinal axis of the source
precise evaluation of the effects of
source anisotropy in the dose
Difficult to make direct measurements
 rely on simulation to get better
accuracy than conventional treatment
planning software
Transverse axis of the source
Comparison with experimental data
Effects of source anisotropy
 validation of the software
Simulation
Simulazioni
Plato
Plato
Data
Misure
2,5
Simulazioni
Simulation
Plato
Plato
2,5
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
Distanza lungo X (mm)
20
Distance along X (mm)
Maria Grazia Pia, INFN Genova - CHEP 2001
30
40
-40
-30
-20
-10
0
10
20
30
Distanza lungo Z (mm)
Distance along Z (mm)
Courtesy F. Foppiano, M. Tropeano
40
F()
Source anisotropy
Plato-BPS treatment planning algorithm
makes some crude approximation
( dependence, no radial dependence)
Courtesy of S. Agostinelli, R. Corvo, F. Foppiano, S. Garelli, G. Sanguineti, M. Tropeano, IST Genova
Plato treatment planning
Maria Grazia Pia, INFN Genova - CHEP 2001
RBE enhancement of a 125I brachytherapy seed with
characteristic X-rays from its constitutive materials
Goal: improve the biological
Compton Interaction Photoelectric effect
effectiveness of titanium
20
encapsulated 125I sources in
permanent prostate implants by
Ejection spectrum
exploiting X-ray fluorescence
15
Titanium shell (50 µm)
Silver core (250 µm)
10
Fluence spectrum
5
4.5 mm
0
All the seed configurations
modeled and simulated with
5
10
15
20
25
30
35
Energy (keV)
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. of Radiation oncology, USA
Maria Grazia Pia, INFN Genova - CHEP 2001
Shell experiments
… up to 300 µm
39  Z  45
20 µm thick
Shell = molybdenum
Up to 10% improvement
Various materials and
thicknesses studied
with
to
replace the Ti shell
1.12
300 m m
200 m m
1.1
1.08
100 m m
1.06
60 mm
150 m m
50 m m
Results
1.04
(RBE at 1 cm)
1.02
20 m m
39
Optimisation of RBE enhancement
50-60 mm shell
Molibdenum
Maria Grazia Pia, INFN Genova - CHEP 2001
Y
40
Zr
41
42
Nb
Mo
43
44
45
Ru
Rh
Element
R. Taschereau, R. Roy, J. Pouliot
Results of the study
Enhanced RBE combined with relatively long half-life of
iodine could mean higher cell kill
1.08
Possible to improve RBE
Applications
- Prostate
- Ocular melanoma
- Coronary brachytherapy
(where a highly localized
dose distribution is desired)
Mo - Y
1.06
M200
1.04
1.02
++ tumors
1
0
1
-- healthy tissues
2
3
4
Distance away from seed
R. Taschereau, R. Roy, J. Pouliot
Maria Grazia Pia, INFN Genova - CHEP 2001
5
M.C. Lopes 1, L. Peralta 2, P. Rodrigues 2, A. Trindade 2
1 IPOFG-CROC Coimbra Oncological Regional Center - 2 LIP - Lisbon
Maria Grazia Pia, INFN Genova - CHEP 2001
Central-Axis depth dose curve for a
10x10 cm2 field size, compared with
experimental data (ionization chamber)
testing
and validation
Validation of phase-space
distributions from a Siemens
KD2 linear accelerator at
6 MV photon mode
1,
M. C. Lopes L. Peralta
A. Trindade 2
2,
P. Rodrigues
2,
1
IPOFG-CROC Coimbra Oncological Regional Center
2
LIP - Lisbon
Maria Grazia Pia, INFN Genova - CHEP 2001
identified as experimental problem
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
Central-Axis depth dose
CT images used to
define the geometry:
a thorax slice from a
Rando
anthropomorphic
phantom
Deviation at –6 cm identified
as an experimental problem
Profile curves at 9.8 cm depth
PLATO overestimate the dose at ~ 5% level
Maria Grazia Pia, INFN Genova - CHEP 2001
Skull bone
Beam plane
Tumor
A more complex set-up
M. C. Lopes1, L. Peralta2, P. Rodrigues2, A. Trindade2
1
IPOFG-CROC Coimbra Oncological Regional Center - 2 LIP - Lisbon
Head and neck with two opposed beams
for a 5x5 and 10x10 field size
An off-axis depth dose taken at one
of the slices near the isocenter
PLATO fails on the air cavities and
bone structures and cannot predict
accurately the dose to tissue that is
surrounded by air
Deviations are up to 25-30%
Maria Grazia Pia, INFN Genova - CHEP 2001
Many other
applications and
new projects
Pixel ionisation
chamber
Relative dose in
water
CT interface + fast/full simulation
Use GEANT4 to obtain
digitally reconstructed
radiographs (DRRs), including
full scatter simulation
Hadrontherapy studies
In vivo dosimetry (mammography, colonscopy),
Superposition and fusion of anatomic and
functional images
This represents a great
PET
improvement over approaches
Intra-operatory radiotherapy
based on ray-casting
etc.
Also theoretical developments to improve the evaluated data libraries
Maria Grazia Pia, INFN Genova - CHEP 2001
- DNA
http://www.ge.infn.it/geant4/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)
Multi-disciplinary Collaboration of
astrophysicists/space scientists
particle physicists
medical physicists
computer scientists
biologists
5.3 MeV  particle in a
physicians
cylindrical volume.






The inner cylinder has a
radius of 50 nm.
Relevance for space: astronaut and airline
pilot radiation hazards, biological
experiments
Applications in radiotherapy,
radiobiology...
Maria Grazia Pia, INFN Genova - CHEP 2001
Prototyping
It is a complex field
-
ongoing active research
Complexity increased by the multi-disciplinary
nature of the project
-
no one masters all the scientific components
(biology, chemistry, physics etc.)
User Requirements
A rigorous
approach to the
collection of the
requirements is
essential
G E A N T 4 -D N A
S im u la tio n o f in te ra ctio n s o f ra d ia tio n w ith b io lo g ica l
syste m s a t th e ce llu la r a n d D N A le ve l
Courtesy A. Brahme (KI)
U ser R equirem ents D ocum ent
Maria Grazia Pia, INFN Genova - CHEP 2001
A challenge for
problem domain
analysis and design!
S tatu s: D eliv ered to E S A o n 2 2 F eb ru ary 2 0 0 1
V ersion : 1.3
P roject: G eant4 -D N A
R eferen ce: D N A -U R D -V 1.03
C reated : 28 D ecem ber 2000
L ast m od ified : 21 F ebruary 2001
P rep ared b y:
M aria G razia P ia (IN F N G enova)
S téphane C hauvie (U niv. of T orino and IN F N T orino and A IR C C )
G abriele C osm o (C E R N )
José M aria F ernandez V area (U niv. of B arcelona)
F ranca F oppiano (IS T G enova - Istituto N azionale per la R icerca sul C ancro)
P etteri N iem inen (E S A /E S T E C )
A da S olano (U niv. of T orino and IN F N T orino)
O n behalf of the G eant4 -D N A C ollaboration
What benefits for HEP?
User requirements
Identification of requirements of common interest
Contribution to sharper requirement specification
…
Testing
Substantial contributions from medical groups
Feedback from usage
in diverse environments
Improves the quality and robustness of the code
Discipline of strict
protocols
Contribution to software process improvement
Incentive to better quality assurance methods
Profit of other fields’ experience in software process for
reliable products
Technology transfer is a helpful argument
with funding agencies for supporting HEP
Maria Grazia Pia, INFN Genova - CHEP 2001
The www was born from HEP…
Geant4 in every hospital?
Maria Grazia Pia, INFN Genova - CHEP 2001
in Savona
Savona
Brachytherapy
at the
Hospital of Savona
A project in progress for the
simulation with
of
brachytherapy 125I sources for
prostate cancer therapy
– Calibration
– Precise dose distribution
installed on the PC of the
Medical Physics Service of the Hospital
Maria Grazia Pia, INFN Genova - CHEP 2001
Meditations…
HEP computing has a potential for technology transfer
- not only the WWW…
- not only Geant4…
The role of HEP: expertise, but also reference
- Physics and software engineering expertise
- Reference to many small groups and diverse activities
Technology transfer: collaboration rather than colonisation
- Valuable contributions from the medical domain (requirements, testing,
rigorous methodologies…)
- New resources into projects of common interest
- Avoid the “colonial” attitude
We would benefit from a greater investment in outreach
- it pays back, in terms of political and scientific return
Maria Grazia Pia, INFN Genova - CHEP 2001
Thanks!
ESA/ESTEC (R. Nartallo, P. Nieminen)
INFN Cosenza (E. Lamanna)
INFN Torino (S. Chauvie, R. Gotta, F. Marchetto, V. Rolando, A. Solano)
IST (S. Agostinelli, R. Corvo, F. Foppiano, S. Garelli, G. Sanguineti, M. Tropeano)
LIP (P. Rodrigues, A. Trindade)
Montreal (R. Taschereau)
PSI (N. Crompton, P. Juelke)
Savona Hospital (G. Ghiso, R. Martinelli)
Geant4 medical users (impossible to mention all…)
Geant4 Collaboration
CERN (S. Giani, J. Knobloch)
Maria Grazia Pia, INFN Genova - CHEP 2001