Application examples for Space, Medicine, Biology

Sébastien IncertiOn behalf of the Geant4

collaboration

2

Content

Medical Radiobiology Space Ray-tracing

Medical

4

GATEhttp://opengate-redesign.healthgrid.org/

5

Harald Paganetti

GEANT4 based proton dose calculation in a clinical environment: technical aspects, strategies and challenges

6

gMocren

KEK

7

CT-simulation with a Rando phantomExperimental data obtained with TLD LiF dosimeter

CT images used to define the geometry:

a thorax slice from a Rando

anthropomorphic phantom

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

Agreement better than 2% between GEANT4 and TLD dosimeters

LIP

8

HadrontherapyKEK

9

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 consistingof 66 absorbers (CH2) interspaced by charge collectors (brass)

Physics settings for using the Geant4 toolkit in proton therapyC. Zacharatou Jarlskog, H. Paganetti, IEEE TNS 55 (2008) 1018 - 1025

10

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.

Organ equivalent dose as a function of phantom age averaged over eight proton fields treating a lesionIn the brain

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

11

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.

LOW DOSE RATE BRACHYTHERAPY contact e-mail: anatoly@uow.edu.au

12

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

MRI-LINAC HYBRID SYSTEMS contact e-mail: anatoly@uow.edu.au

13

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 contact e-mail: anatoly@uow.edu.au

14

Digital Phantom Reconstructed Image

PROTON COMPUTED TOMOGRAPHY

15

Use pCT detector modules as Compton Camera to record activity distribution generated by proton treatment beam

• If feasible, pCT detectors will provide complete planning and verification tool!

511keV ’s generated by +

annihilation

Compton scatter in Si planes

Full energy collection in scintillator

crystal

PROTON THERAPY BEAM VERIFICATION

16

I nfluence of the step size correction on the isodoses position

High discrepancies with the analytical software Plaque Simulator

Comparisons of isodose contours in water from a CCB applicator using GATE_G4.9.0. Doses have been normalized to 100% at 1mm on the central axis.

106Rh spectrum

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

17

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

18

• 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)

PISA UNIVERSIY AND INFN, ITALYcontact e-mail: valeria.rosso@pi.infn.it

Radiobiology

20

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

Biological damages (DSB)Cellular phantoms DNA molecule

21

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

Kindly provided by Marion Bug & Anatoly Rosenfeld

Centre for Medical Radiation Physics University of Wollongong, Australia

Presented at the 13th Geant4 collaboration workshop

22

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 of cluster size. Comparison of G4-code (solid lines) with MC-code from PTB (dashed lines)

Mean ionisation cluster-size vs. electron energy, comparison of our data (G4) with the MC-code from PTB

Probability VS cluster sizeProbability VS cluster sizeCluster size VS EnergyCluster size VS Energy

23

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

(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

Kindly provided by Djamel Dabli & Gérard Montarou Laboratoire de Physique Corpusculaire

Université Blaise Pascal, IN2P3/CNRS, Aubière, France

Kindly provided by Djamel Dabli & Gérard Montarou Laboratoire de Physique Corpusculaire

Université Blaise Pascal, IN2P3/CNRS, Aubière, France

24

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

Proximity functions

Proximity functionProximity function

25

Cellular irradiation @ CENBG

a b

c d

3

1 2

1

23

Chemical composition

Mean dose in nucleus

(Gy)

Liquid water

0.14 ± 0.02

Reference cell (ICRU)

0.32 ± 0.06

CENBG measureme

nts

0.38 ± 0.07

Ion b

eam

anal

ysis

with

pro

tons

(PIX

E, R

BS)

3D high resolution phantom

Confocal microscopy of HaCat cell

Geant4 Microdosimetry

Cellular

irradiatio

n

3 MeV

alphas

Cytoplasm

Nucleus

Space science

27

Chandra X-ray observatory, with similar orbit, experienced unexpected degradation of CCDs

Possible effects on XMM?Baffles

X-ray detectors(CCDs)

Mirrors

Telescope tube

X-ray Multi-Mirror mission (XMM)

Launch December 1999 Perigee 7000 km apogee 114000 km Flight through the radiation

belts

XMM

28

astrophysics-ray bursts-ray bursts

AGILE

GLAST

Typical telescope: Tracker Calorimeter Anticoincidence conversion

electron interactions multiple scattering d-ray production charged particle tracking

FGST

GLAST

FGSTAGILE

29MAXIISS Columbus AMS

EUSO

Bepi Colombo SWIFT

LISA

Smart-2

ACE

INTEGRAL

Astro-E2

JWSTGAIA

Herschel

Cassini

FGST

XMM-Newton

30

Cou

rtes

y T

. Ers

mar

k, K

TH

Sto

ckho

lm

ISS

31

X-Ray Surveys of Asteroids and Moons

Induced X-ray line emission:indicator of target composition(~100 mm surface layer)

Cosmic rays,jovian electrons

Geant3.21

G4 “standard”

Geant4 low-E

Solar X-rays, e, p

Courtesy SOHO EIT

C, N, O line emissions included

ESA Space Environment & Effects Analysis Section

32

Bepi Colombo: X-Ray Mineralogical Survey of Mercury

Alfonso Mantero, Thesis, Univ. Genova, 2002

Space Environments Space Environments and Effects Sectionand Effects Section

BepiColomboESA cornerstone mission to Mercury

Courtesy of ESA Astrophysics

BepiC

33

Planetary radiation environments

L. Desorgher, Bern U.

Planets

PLANETOCOSMICS by L. Desorgher et al.

34

Radiation damage

35

X- and Gamma-ray astronomy

“Suzaku” Observatory (ISAS/JAXA and many universities)

Launched on 2005-07-10

•XIS (X-ray CCD camera) [0.3—12 keV]•HXD (Hard X-ray Detector) [10—600 keV]

High-precision and Low-noisedetector systems

The 5th Japanese X-ray astronomy satellite

35

36

Background-event spectrum of XIS

Physics processes

•Electromagnetic Interaction(down to 250eV)

•Hadronic Interaction

Used Geant4 outputs:

•Physics process of particle generation, position, energy, solid-ID•Energy deposition and its physics process•ParentID 、 TrackID 、 StepNumber

Succeeded in representing the BGD spectrum and resolving the BGD generation mechanism

Geant4 simulation (energy deposition) + charge-diffusion simulation in CCD

Primary events from 4 Sr

36

37

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 + PhoswitchBGO 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 375th Space Users' Workshop and Japan's activity (2008-10-07)

38

ESA / space resources

http://geant4.esa.int/

GRASPLANETOCOSMICSMULASSISSPENVISSSATGEMAT…

Ray tracing

40Courtesy of V.D.Elvira (FNAL)

Geant4 for beam transportation

41Courtesy of G.Blair (CERN)

42

4565

90°

250

3150

5100

100

40

100

40

11°

300

X400 400

90° analysismagnet

Switchingmagnet

Image plan

Object collimator DiaphragmDiaphragm

Object5 µm in diameter

DOUBLET TRIPLET Electrostatic deflection

Sin

gle

tro

n in

cid

ent

bea

m

Image < 50 nm FWHMsame prediction as Oxray, Zgoubi…

Intermediate image60 nm x 80 nm

Sub-micron raytracing @ CENBG : nanobeam line design

3D field mapOM50 quadrupoles

43

G4BeamLinehttp://www.muonsinc.com

44

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 http://cern.ch/geant4

45

Earth magnetosphere

ISS

GAIA

FGST

Brachytherapy

PET Scan(GATE)

Hadrontherapy

DICOM dosimetry

Medical linac

ATLAS, CMS, LHCb, ALICE @ CERN

BaBar, ILC…

Physics-Biology