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

Fragmentation experimentsFragmentation experiments

LNSLNS

Status Report

C.Agodi TPS collaboration meeting

Torino 5-6 novembre 2009

What is the contribution to Ion Therapy Treatment Planning ?

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.

Energy losses can be assessed via Monte Carlo simulation mainly to account for fragmentation nuclear processes.

Cross section fragmentation data

RBE table remodels the physical dose deposition including the hadron

specificity

Cross section fragmentation data

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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.

Planning Treatment Volume

Computed Tomography

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

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Projectile

Reaction atIntermediate energy

Target

Nuclei Fragmentation

12C beam from CS

Target

Hodo Big Hodo small

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Our Measurements at LNS: The ExperimentOur 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.

INFN Laboratory Nazionali del Sud , Catania - Sicily - Italy

Superconducting cyclotron

LNS – INFN, Catania

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°)

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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)

projectile fragment

Experimental set – up

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FRAG (April 2009) 12C+12C,197Au,CH @62MeV

C + C N° ≈ 5·1012

I ~ 40 – 80 pA

C + CH2 N° ≈ 1·1012

I ~ 40 – 60 pA

C + Au N° ≈ 11·1012

I ~ 180 – 230 pA

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E-E plot

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Measured vs calculated angular differential cross Measured vs calculated angular differential cross sectionssections

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

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“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.RomanoINFN: LNS, LNF, Roma2, Roma3, Milan, Turin, Roma Tor Vergata

S.Leray, M.D. Salsac, A.Boudard, J.E. Ducret, M. Labalme, F. Haas, C. RayDSM/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. SantinESA

Proposal of Experiment at SIS

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

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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

Estimation of the systematic errors on momentum and angle as reconstructed

with ALADIN

Fragmentation measurements at GSIFragmentation measurements at GSI

The G-PAC approved with high priority the key measurements:

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•C+C @ 0.2, 0.4 and 1.0 AGeV

•C+Au @ 0.2, 0.4 AGeV

•O+C @ 0.2, 0.4 AGeV

Hadrotherapy

Analysis Exp.Apr.09

LNS@80AMeV (deadline proposal 12/09)

S371@GSI

Fragmentation 2010

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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.

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New mixed inner radiation field !

New mixed inner radiation field !

projectile

target

projectile fragment

target fragment

Outer radiation fields

Interaction of the radiation withthe spacecraft hulls, the body... Target Fragments Projectile fragments Target Fragments Projectile fragments

… … lower chargelower charge … lower charge … lower charge than target than primariesthan target than primaries… … high LET … mixed LET high LET … mixed LET … … short ranges … long rangesshort ranges … long ranges

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

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Why fragmentation measurement in hadrontherapy?

Disadvantages

Disadvantages

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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

•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

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

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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.

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Our Measurements at LNS: The ExperimentOur Measurements at LNS: The Experiment

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°

Hodo SmallHodo Small

TargetTarget

Hodo BigHodo Big

E CsI(Tl)