Particle Physics Software aids Medicine Accurate geometry and material modeling in the fight against cancer Precise physics models for radiation interactions.

Particle Physics Software aids MedicineParticle Physics Software aids Medicine

Accurate geometry and material modeling

in the fight against cancer

Precise physics models for radiation interactions with matter

Friendly interface through the World Wide Web

Powerful data analysis tools

The GRID for fast and cheap processing on distributed

computing resources

Open source code providing advanced technologies to

developing countries at no cost

cell

Interaction of radiation with biological structures

Radiation can be electrons, photons, protons, ions, neutrons Radiation interacting with molecules loses energy thanks to electric interactionselectric interactions

If the energy deposited in a cell is sufficiently high, the cell dies

This property of radiation is used to fight cancerfight cancer: beams of radiation, or radioactive sources, are used to destroy tumour cells, while preserving the surrounding healthy tissue

Before the radiotherapy treatment experts Before the radiotherapy treatment experts study the configuration of the treatment with the help of study the configuration of the treatment with the help of

softwaresoftware, ,

to determine the optimal to determine the optimal dosedose (energy deposited per unit of mass)(energy deposited per unit of mass) to be delivered in the patient’s bodyto be delivered in the patient’s body

RadiotherapyRadiotherapy with external beamswith external beams

Direction of the beam

Energy of the beam

Time of exposure of the patient

...

Brachytherapy with radioactive sourcesBrachytherapy with radioactive sources

Number of radioactive sources needed

Position of the sources in the body

Time of exposure of the patient

...

to develop to develop a a general purposegeneral purpose

precise precise dosimetric system

with the capability of

realistic geometryrealistic geometryand material modelingand material modeling

interface to CT imagesinterface to CT images

with a user-friendly interfaceuser-friendly interface

atat low costlow cost

adequate adequate speedspeed for clinical usage for clinical usageperforming atperforming at

challenge

How particle physics software responds to the

Ocular Ocular melanoma can melanoma can

be treatedbe treatedwith a with a

proton beam proton beam

Powerful software toolssoftware tools, originally developed to model complex geometrygeometry for the detectors at the CERN LCERN Largearge H Hadron adron CColliderollider, allow to simulate the

proton beam line realistically

The CATANA proton beam line in Catania, Italy

The set-up of the proton beam line is The set-up of the proton beam line is optimized for cancer treatment by optimized for cancer treatment by

means of a means of a

software simulationsoftware simulation

ATLASCMS

Monte Carlo simulation of the CATANA beam line

Software Software toto model geometry model geometry

The geometry and material model of a

patient’s anatomy can be reconstructed with great

accuracy from Computerized Computerized

Tomography imagesTomography images

Thanks to a realistic anatomyrealistic anatomy,, it is possible to study the effect of radiationeffect of radiation on different tissuesdifferent tissues with great precisionprecision

Thanks to a realistic anatomyrealistic anatomy,, it is possible to study the effect of radiationeffect of radiation on different tissuesdifferent tissues with great precisionprecision

Commercial treatment planning software systems approximate all human tissues to water

A special modulespecial module interfaced to the Geant4 Toolkit allows to load CT load CT

images into a simulation applicationimages into a simulation application

Sophisticated software tools have been developed in the Geant4

Simulation Toolkit to track particles

in magnetic fields

Geant4 simulation of protons trapped in the earth magnetic field

purging magnet electrons

photons

A pure beam of photonsphotons is left for therapeutic usage

The design of the magnetic field is optimized to deflect electronselectrons away from the patient

The same software tools are used to design the

purging magnetpurging magnet of a new accelerator for

radiotherapyradiotherapy

A sample of physics models for hadron and ion interactions with matter

Bragg peak

antiprotons

protonsions

Fe lines

GaAs lines

Atomic relaxationFluorescence

Auger effect

A sample of physics models for electron and photon interactions with matter

Software developed for particle physics

experiments provides an ample variety of precise physics physics

modelsmodels to describe radiation

interactions with matter

Software developed for particle physics

experiments provides an ample variety of precise physics physics

modelsmodels to describe radiation

interactions with matter

Particle physics software is subject to a rigorous validationvalidation by many independentindependent users in diversediverse domains worldwideworldwide

Particle physics software is subject to a rigorous validationvalidation by many independentindependent users in diversediverse domains worldwideworldwide

Validation is performed through comparison to experimental data:

manufacturer data, protocol data,

data from direct experiments

0 10 20 30 40 500,0

0,2

0,4

0,6

0,8

1,0

1,2 Simulazione Nucletron Misure

Dose %

Distanza lungo Z (mm)Distance along Z (mm)

SimulationNucletronData

F. Foppiano et al., IST Genova

superficial brachytherapysuperficial brachytherapy

experimental mesurements

G. Ghiso, S. Guatelli S. Paolo Hospital Savona

interstitial brachytherapyinterstitial brachytherapy

Validation is especially important in sensitive Validation is especially important in sensitive applications, applications,

such as in medicine!such as in medicine!

Commercial treatment planning systems are based on analytical methods, because of speed constraints

Often crude approximationscrude approximations in geometrygeometry, materialsmaterials and physics physics are made to simplify the analytical calculations

Particle physics software is intrinsically more precisemore precise, because of its capabilities to model

geometrygeometry

materialsmaterials (e.g. body tissue)

physics interactionsphysics interactions

realisticallyrealistically, then using these models

with Monte Carlo methodsMonte Carlo methods

Precision is important!Precision is important!In some tumours sites (ex: larynx T2/T3-stage)

a 5% underdosage will decrease local tumour a 5% underdosage will decrease local tumour control probability from ~75% to ~50%control probability from ~75% to ~50%

Central-Axis depth dose

particle physics

commercial

2/ndf (Plato) = 6.71 2/ndf (TMS) = 0.812/ndf (Geant4) = 0.52

The

Particle tracksParticle tracks in a section of theATLASATLAS detector at the

CERN Large Hadron ColliderCERN Large Hadron Collider

Particle physics experiments need powerful graphic toolsgraphic tools

to visualize complex detectorsdetectors and trackstracks resulting from

physics interactions

A brachytherapy source in a Leipzig applicator used

to cure skin cancerskin cancer

These tools allow to visualize the effects of a

radioactive sourceradioactive source, enclosed in a special applicator, used for the therapy of skin cancerskin cancer

Visualisation tools in

the

Simulation Toolkit

0.16 mGy =100%

Isodose curvesIsodose curves

Data Analysis ToolsData Analysis Tools originally developed for experiments at the Large Hadron

Collider allow to calculate quantities of clinical allow to calculate quantities of clinical interestinterest

Dose at various radiation penetration depthsDose at various radiation penetration depths

AIDAAIDA (Abstract Interfaces for Data Analysis) and Anaphe Anaphe Analysis Tool

Geant4 applicationWeb interface

Type of brachytherapic source

Phantom configuration

Number of events

The World Wide WebWorld Wide Web, originally developed at CERN for particle physics

experiments, offers a friendly user interfaceuser interface to configureconfigure, control control and runrun software applications

The World Wide WebWorld Wide Web, originally developed at CERN for particle physics

experiments, offers a friendly user interfaceuser interface to configureconfigure, control control and runrun software applications

In usual clinical practice the software for radiotherapic treatment planning should be

easily usable even by non-specialists

Configuration of a simulation for brachytherapy (therapy with radioactive sources

The powerful physicsphysics and geometrygeometry modeling techniques enable versatile applications of the same codeversatile applications of the same code

to many diverse medical problems

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

Same simulation and analysis application software for:

endocavitary brachytherapy(uterus, vagina, lung cancer)

interstitial brachytherapy(prostate cancer)

superficial brachytherapy (skin cancer)

...while commercial software is specialised for one specific application only

same software = lower cost to hospitalssame software = lower cost to hospitals

The versatility of particle physics software is such, that it is used to study not only

the effect of radiation on human bodyeffect of radiation on human bodyin conventional applications like radiotherapy,

but also in extreme conditions, such as on astronauts in interplanetary missionsastronauts in interplanetary missions,

where they are subject to solar and cosmic radiation

from hospitals...

...to Mars

The same software tools can be applied to study the effect of radiation to airline staff in intercontinental flights

The speedspeed of software execution is fundamental when the medical staff has to take quick decisions about the treatment planning of the patients

Even if recognized as more precise, Monte Carlo methods have not been used so far in clinical practice, because they are much slowerslower than analytical methods

MasterMaster--WorkerWorker modelmodelParallel execution of independent tasksVery typical in many scientific applicationsUsually applied in local clusters

AdequateAdequate speedspeed for clinical usage can be achieved by running the Monte Carlo-based software in

parallelparallel on a farm of inexpensive inexpensive PCsPCs

The emerging Grid Grid technology, adopted by the experiments at the CERN Large Hadron ColliderLarge Hadron Collider,

allows seamless access to geographically distributed computing resources

In the near future hospitals will be able to access PCs scattered all over the world for parallel processing, without even needing to own their own farm

of PCs

Any hospital

– even small ones, or in developing countries, that cannot even small ones, or in developing countries, that cannot afford expensive commercial software systemsafford expensive commercial software systems –

may have access to advanced software technologies and tools for radiotherapy

at very low or even no cost

Thanks to

G. Cosmo, J. Moscicki, A. Pfeiffer, CERN

G.A.P. Cirrone and G. Cuttone, INFN-LNS, Italy

F. Foppiano, IST-National Institute for Cancer Research, Italy

S. Larsson, Karolinska Institute, Sweden

L. Peralta, P. Rodrigues, A. Trindade, LIP, Portugal

G. Ghiso, S. Paolo Hospital of Savona, Italy

R. Taschereau, UCSF, USA

L. Archambault, L. Beaulieu, J.F. Carrier, V.H. Tremblay, Univ. Laval, Canada

Geant4 Collaboration

AIDA Collaboration