Fragmentation experiments Status Report LNS C.Agodi TPS collaboration meeting Torino 5-6 novembre 2009

What is the contribution to Ion Therapy Treatment Planning ? The Treatment Planning Systems (TPS) is a complex computer system that helps both to design radiation treatments and to compute the dose to the patient. The optimal TPS should be interactive and evaluated in real time. Innovative contribution in this field is particularly needed in case of clinical ions beams. Computed Tomography Energy losses can be assessed via Monte Carlo simulation mainly to account for fragmentation nuclear processes. Cross section fragmentation data Planning Treatment Volume RBE table remodels the physical dose deposition including the hadron specificity Cross section fragmentation data LNS

Projectile fragmentation Reaction products : have velocity near to the primary beam; are emitted mostly in the forward direction The detection system has to be efficient in the interest angular region Projectile Reaction at Intermediate energy Target Nuclei Fragmentation LNS

In 2010 we plan to use different beams up to 80 AMeV. Our Measurements at LNS: The Experiment We already measured the 12C fragmentation on 197Au and 12C targets with 32 and 62 AMeV CS beams at LNS-INFN, Catania In 2010 we plan to use different beams up to 80 AMeV. An hodoscope (hodo big and hodo small) composed of two-fold and three-fold telescopes has been used for identify fragments produced in the reaction and measure the energy (θlab between 0° and ±20°) INFN Laboratory Nazionali del Sud , Catania - Sicily - Italy 12C beam from CS Target Hodo Big Hodo small LNS – INFN, Catania Superconducting cyclotron LNS LNS

Complete characterization Experimental set – up projectile fragment Complete characterization and coverage near 90% HODO-BIG: 89 three-folds telescopes array 4.5°-22.5° Si(50μm)-Si(300μm)-CsI(6cm) HODO-SMALL: 81 two-folds telescopes array 4.5°-4.5° Si(300μm)-CsI(10cm) LNS

FRAG (April 2009) 12C+12C,197Au,CH @62MeV LNS FRAG (April 2009) 12C+12C,197Au,CH @62MeV C + C N° ≈ 5·1012 I ~ 40 – 80 pA N° ≈ 1·1012 C + CH2 I ~ 40 – 60 pA C + Au N° ≈ 11·1012 I ~ 180 – 230 pA

DE-E plot LNS

Measured vs calculated angular differential cross sections

CHARGED PARTICLE PRODUCTION CROSS SECTION PRELIMINARY COMPARISONS – LNS DATA AT 62 AMeV Carbon incident General better agreement of JQMD with our modifications but still worse agreement in the intermediate part of the spectra LNS

Proposal of Experiment at SIS “Extensive study of nuclear reactions of interest for medical and space applications.” G.Cuttone, F.Marchetto, G.Raciti, E.Iarocci, V.Patera, C.Agodi, C.Sfienti, E.Rapisarda, M. De Napoli, F. Giacoppo, M.C. Morone, A. Sciubba, G.Battistoni, P.Sala, Sacchi, E.Spiriti, G.A.P.Cirrone, F.Romano INFN: LNS, LNF, Roma2, Roma3, Milan, Turin, Roma Tor Vergata S.Leray, M.D. Salsac, A.Boudard, J.E. Ducret, M. Labalme, F. Haas, C. Ray DSM/IRFU/SPhN CEA Saclay, IN2P3 Caen, Strasbourg, Lyon M. Durante, D. Schardt, R. Pleskac, T. Aumann, C. Scheidenberger, A. Kelic, M.V.Ricciardi, K.Boretzky, M. Heil, H. Simon, M. Winkler GSI P. Nieminen, G. Santin ESA LNS

GSI-GPAC: «Extensive study of nuclear reactions of interest for Medical and Space Applications»: S371 LNS

We can get the goal of 3% error in Double Differential Cross Section Estimation of the systematic errors on momentum and angle as reconstructed with ALADIN Assuming that the dependence of the acceptance on Pt can be determined with a 20% error then all the slopes should be determined with an accuracy better than 2.5 %, in the worst case (Z = 2) We can get the goal of 3% error in Double Differential Cross Section

Fragmentation measurements at GSI The G-PAC approved with high priority the key measurements: C+C @ 0.2, 0.4 and 1.0 AGeV C+Au @ 0.2, 0.4 AGeV O+C @ 0.2, 0.4 AGeV LNS

Fragmentation 2010 Analysis Exp.Apr.09 LNS@80AMeV S371@GSI LNS Hadrotherapy Analysis Exp.Apr.09 LNS@80AMeV (deadline proposal 12/09) S371@GSI LNS

12C Fragmentation measurements In order to perform a systematic study of projectile fragmentation intermediate energies, we measured the 12C fragmentation cross section on different targets at 32 and 62 AMeV at LNS. New mixed inner radiation field ! projectile target projectile fragment target fragment Outer radiation fields Interaction of the radiation with the spacecraft hulls, the body... Target Fragments Projectile fragments … lower charge … lower charge than target than primaries … high LET … mixed LET … short ranges … long ranges LNS

Sezione d’urto di produzione di particelle cariche ( particelle α) CONFRONTO PRELIMINARE – DATI LNS (12C at 62 AMeV) In generale miglior accordo con il JQMD con le nostre modifiche . Resta comunque una discrepanza notevole nella parte intermedia dello spettro LNS

Why fragmentation measurement in hadrontherapy? LNS Why fragmentation measurement in hadrontherapy? Light ions Advantages Better Spatial selectivity in dose deposition: Bragg Peak Reduced lateral and longitudinal diffusion High Conformal dose deposition High Biological effectiveness Treatment of highly radiation resistent tumours, sparing surrounding OAR Disadvantages Fall of dose in the tumour target region Unwanted dose in normal tissue behind the target volume An extensive database on nuclear fragmentation cross sections and fluences are needed at therapeutic energy region Il metodo Monte Carlo in radioterapia - pratica clinica e strumenti tecnologici 17

Disadvantages of carbon ions LNS Disadvantages of carbon ions Nuclear Fragmentation of 12C beam in the interaction processes with: energy degraders, biological tissues Further problem different biological effectiveness of the fragments Mitigation and attenuation of the primary beam Dose over the Bragg Peak : p ~ 1-2 % C ~ 15 % Ne ~ 30 % Production of fragments with higher range vs primary ions

Carbon ions advantages LNS Carbon ions advantages Lower lateral and longitudinal diffusion vs. proton More precise energy deposition Optimal RBE profile - penetration depth position. Online PET for depth deposition monitoring Good Compromise between RBE and OER.

Our Measurements at LNS: The Experiment Target Hodo Small Hodo Big E CsI(Tl) The Hodo-small, set up at a distance of 80 cm from the target consisted of 81 two-fold telescopes: 300 µm Silicon detectors 1x1 cm2 of active area followed by a 1x1 cm2 and 10 cm long CsI(Tl) and covered the angular range θlab=±4.5°. The Hodo-big, set up at a distance of 0.6 m from the target, consisted of 89 three-fold telescopes 50 µm + 300 µm Silicon detectors both having 3x3 cm2 surface followed by a 6 cm long CsI(Tl)of the same surface. It covered the angular range θlab between ±4.5° and ±20° LNS