Particle Physics Software aids Medicine

1. Precise physics models for radiation interactions with matter Open source code providing advanced technologies to developing countries at no cost Accurate geometry and material modeling Powerful data analysis tools The GRID for fast and cheap processing on distributed computing resources Friendly interface through the World Wide Web Particle Physics Software aids Medicine in the fight against cancer

2. cell Interaction of radiation with biological structures • Radiation can be electrons, photons, protons, ions, neutrons • Radiation interacting with molecules loses energy thanks to electric interactions If the energy deposited in a cell is sufficiently high, the cell dies This property of radiation is used to fight cancer: beams of radiation, or radioactive sources, are used to destroy tumour cells, while preserving the surrounding healthy tissue

3. Before the radiotherapy treatment experts study the configuration of the treatment with the help of software, to determine the optimal dose(energy deposited per unit of mass) to be delivered in the patient’s body Radiotherapywith external beams Direction of the beam Energy of the beam Time of exposure of the patient ... Brachytherapy with radioactive sources Number of radioactive sources needed Position of the sources in the body Time of exposure of the patient ...

4. How particle physics software responds to the challenge dosimetric system precise to develop a general purpose realistic geometry and material modeling with the capability of interface to CT images with a user-friendly interface low cost at adequate speed for clinical usage performing at

5. CMS ATLAS The CATANA proton beam line in Catania, Italy Ocular melanoma can be treated with a proton beam Software to model geometry The set-up of the proton beam line is optimized for cancer treatment by means of a software simulation Powerful software tools, originally developed to model complex geometryfor the detectors at the CERN Large Hadron Collider, allow to simulate the proton beam line realistically Monte Carlo simulation of the CATANA beam line

6. The geometry and material model of a patient’s anatomy can be reconstructed with great accuracy from Computerized Tomography images A special module interfaced to the Geant4 Toolkit allows to load CT images into a simulation application Thanks to a realistic anatomy, it is possible to study the effect of radiation on different tissues with great precision Commercial treatment planning software systems approximate all human tissues to water

7. Geant4 simulation ofprotonstrapped in theearth magnetic field purging magnet electrons A pure beam of photons is left for therapeutic usage photons The design of the magnetic field is optimized to deflect electrons away from the patient Sophisticated software tools have been developed in the Geant4 Simulation Toolkit to track particles in magnetic fields The same software tools are used to design the purging magnet of a new accelerator for radiotherapy

8. Atomic relaxation Fluorescence Auger effect Fe lines protons GaAs lines antiprotons Software developed for particle physics experiments provides an ample variety of precise physics models to describe radiation interactions with matter A sample of physics models for electron and photoninteractions with matter A sample of physics modelsfor hadron and ioninteractions with matter ions Bragg peak

9. Simulation Nucletron Data G. Ghiso, S. Guatelli S. Paolo Hospital Savona experimental mesurements F. Foppiano et al.,IST Genova superficial brachytherapy Distance along Z (mm) interstitial brachytherapy Particle physics software is subject to a rigorous validation by many independent users in diverse domains worldwide Validation is performed through comparison to experimental data: manufacturer data, protocol data, data from direct experiments Validation is especially important in sensitive applications, such as in medicine!

10. Particle physics softwareis intrinsicallymore precise, because of its capabilities to model • geometry • materials(e.g. body tissue) • physics interactions • realistically, then using these models • with Monte Carlo methods Central-Axis depth dose particle physics commercial 2/ndf (Geant4) = 0.52 2/ndf (Plato) = 6.71 2/ndf (TMS) = 0.81 Commercial treatment planning systems are based on analytical methods, because of speed constraints Often crude approximations in geometry, materials and physics are made to simplify the analytical calculations Precision is important! In some tumours sites (ex: larynx T2/T3-stage) a 5% underdosage will decrease local tumour control probability from ~75% to ~50%

11. Particle physics experiments need powerfulgraphic toolsto visualize complex detectors and tracks resulting from physics interactions These tools allow to visualize the effects of a radioactive source, enclosed in a special applicator, used for the therapy of skin cancer Visualisation tools in the Simulation Toolkit Particle tracksin a section of the ATLAS detector at the CERN Large Hadron Collider A brachytherapy source in a Leipzig applicator used to cure skin cancer The

12. 0.16 mGy =100% Isodose curves Data Analysis Tools originally developed for experiments at the Large Hadron Colliderallow to calculate quantities of clinical interest Dose at various radiation penetration depths AIDA(Abstract Interfaces forData Analysis) and Anaphe Analysis Tool

13. 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 World Wide Web, originally developed at CERN for particle physics experiments, offers a friendly user interface to configure, control and run software applications Type of brachytherapic source Phantom configuration Number of events Geant4 application Web interface

14. The powerful physics and geometrymodeling techniques enable versatile applications of the same code to many diverse medical problems Same simulation and analysis application software for: endocavitary brachytherapy (uterus, vagina, lung cancer) interstitial brachytherapy (prostate cancer) superficial brachytherapy (skin cancer) same software = lower cost to hospitals ...while commercial software is specialised for one specific application only

15. from hospitals... ...to Mars The versatility of particle physics software is such, that it is used to study not only the effect of radiation on human body in conventional applications like radiotherapy, but also in extreme conditions, such as on astronauts in interplanetary missions, where they are subject to solar and cosmic radiation The same software tools can be applied to study the effect of radiation to airline staff in intercontinental flights

16. The speed 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 slower than analytical methods Adequatespeed for clinical usage can be achieved by running the Monte Carlo-based software in parallel on a farm of inexpensive PCs Master-Workermodel Parallel execution of independent tasks Very typical in many scientific applications Usually applied in local clusters

17. 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 The emerging Grid technology, adopted by the experiments at the CERN Large Hadron Collider, allows seamless access to geographically distributed computing resources Any hospital – even small ones, or in developing countries, that cannot afford expensive commercial software systems – may have access to advanced software technologies and tools for radiotherapy at very low or even no cost

18. 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