Budker Inst. of PhysicsIHEP ProtvinoMEPHI Moscow Pittsburg University

MEDICALAPPLICATIONS

S. Agostinelli1, S. Chauvie2,5, F. Foppiano1, S. Garelli1, F. Marchetto2, P. Nieminen3, M.G. Pia4,

V. Rolando2, A. Solano2

1 Istituto Nazionale per la Ricerca sul Cancro, Italy2 Univ. of Torino and INFN Sezione di Torino, Italy

3 ESA/ESTEC, The Netherlands4 INFN Sezione di Genova, Italy and CERN, Switzerland

5 IRCC Institute for Cancer Research and Treatment, Italy

- DNAMulti-disciplinary Collaboration of

astrophysicists and space scientists particle physicists medical physicists biologists physicians

-sponsored project, in collaboration with

Study of radiation damage at the cellular and DNA level in the space radiation environment(and other applications, not only in the space domain)

http://www.ge.infn.it/geant4/dna/

Object Oriented Toolkit for the simulation of the passage of particles through matter

The transparency of physics

Advanced functionalities in geometry, physics, visualisation etc.

Extensibility to satisfy new user requirements

thanks to the OO

technology

Adopts standards wherever available (de jure or de facto)

Use of evaluated data libraries

Quality Assurance based on sound software

engineering

Subject to independent validation by a large user

community worldwideUser support organization

by a large international Collaboration of experts

Geant4 provides Geant4 provides various features various features

relevant for relevant for medical medical

applicationsapplications

Low Energy Electromagnetic Physics

LowLow EnergyEnergy ElectromagneticElectromagneticpackage extends the

coverageof physics interactions

down to 250 eV250 eV for electrons and • based on the LLNL data libraries• shell effects

down to ~ 1 keV~ 1 keV for hadrons and ions• Bethe-Block above 2 MeV• Ziegler and ICRU parameterisations

(with material dependence)

• free electron gas model• quantal harmonic oscillator model• charge dependence (Barkas effect)

http://www.ge.infn.it/geant4/lowE/

Geant4 Low Energy Electromagnetic Physics

0.01 0.1 1 10

0.1

1

10

Geant4 LowEn NIST

/

(cm

2 /g

) in

wat

er

Photon Energy (MeV)

Photon attenuation coefficient in water

Ion ionisation

3 m m ste e l c a b le

5.0 m m

0.6 m m

3.5 m m

1.1 m m

Ac tive Ir-192 C o re

Geant4 allows a complete

flexible description of

the real geometry

Brachytherapy

Brachytherapy is a medical therapy used for cancer treatments

Radioactive sources are used to deposit therapeutic doses near tumors while preserving surrounding healthy tissues

0

30

60

90

120

150

180

The dose deposition is not isotropic due to source geometry and auto-absorption, encapsulation and shielding effects

Anisotropy

Radioactive Decay Module is capable of handling the generation of the whole radioactive chain of the 192Ir source

Isodose curves

-Selectron 192Ir source

The simulated source is placed in a 30 cm water box

1 million 1 mm3 voxels

Pixel Ionisation Chamber

Relative dose with 6 MV photons beam

Dosimetric Studies

Deposited energy vs Depth in water

and experimental data

Bragg Peak of Protons in Water

Magic CubeRelative dose with

270 MeV protons beam in water

Deposited energy vs Depth in water

and experimental data

Work in progress

Work in progressIn vivo TLD dosimetry

Simulation of the energy deposition of low energy photons in TLD LiF100 nanodosimeters

Used to calculate dose to patient in radiodiagnostic examinations:

mammography virtual colonscopy

CT image interface

Interface between Geant4 and DICOM CT scan images format in order to perform in tissue simulation