1. Proposal for a new INFN experiment
Proposal for a new INFN experiment on fragmentation for hadrontherapy applications
G. Battistoni

2. Target fragmentation & proton RBE
Currently the contribution of target fragments and of the increasing RBE near the PB is implicit (ICRU reccommendation RBE=1.1)
Lately has been pointed out possible impact of variable proton RBE on clinical NCTP values
RBE=1.1
Variable RBE
Wedenberg 2014 Med Phys

3. What about Target Fragmentation?
Target fragmentation in proton therapy: gives contribution also outside the tumor region!
Cell killed by ionization
Recoil fragment generated
About 10% of biological effect in the entrance channel due to secondary fragments
Largest contributions of recoil fragments expected from
He, C, Be, O, N
These might be the source of an RBE>1.1
more damage than expected to healthy tissues!!
R=1/40
R=1/8
250 MeV proton beam in water
Entrance channel 0.5 KeV/mum and 0.2 Gy -> about 3% cell killing
Bragg peak 2.5 keV/mum and 2 Gy ‘_ about 60% cell killing
Cancers 2015,7 Tommasino & Durante

4. p➜ X (C,O) scattering @200 MeV
p-N elastic interaction and the light fragment production (p,d,t) are quite well known. More uncertainty on He fragments.Missing data on heavy fragments (A>4), largely unknown.Available nuclear models in MC code not yet reliable
Very low energy, very short range fragments!!
Cancers 2015,7 Tommasino & Durante
Analitic model results on p+O

5. p scattering on Brain tissue @200 MeV
MC (FLUKA) prediction of production of heavy fragments for 200 MeV p on “BRAIN” : production of He & C
dN/dlog(E[GeV])
4He
12C
dN/dlog(E[GeV])
15 μm range
15 μm range
for RBE: the knowledge of dσ/dE is mandatory!!
Ekin tot (GeV)
Ekin tot (GeV)

6. Radiobiology desiderata
To implement sound radiobiological models the requirements is a improvement of the knowledge of the p-> patient (i.e. p-> H,C,O that are the 98% of human body mass ) interaction at MeV.
Measure the heavy fragment (Z>2) production cross section with maximum uncertainty of 5%
Measure the fragment energy spectrum (i.e. ds/dE) with an energy resolution of the order of 1 MeV/A
Charge ID at the level of 2-3%
Isotopic ID at the level of 5%
Not needed accurate angular measurement
If possible study also the light ions productions

7. A new exp. is being proposed
FOOT:
FragmentatiOn Of Target
Rm1, Rm2, LNF, Bo, Mi, To, Pi, Na, TIFPA, LNS
To perform a fragmentation measurement in the
Inverse Kinematics Approach:
100 – 300 MeV/u C,O,N beams against a H-rich target
Detector designed for: Z-id, A-id, Energy, Angle C
CH2
The fragmentation cross section on H can be obtained by subtraction.

8. DE/DX & TOF measurement
The FOOT Detector
BGO calorimeter
Combines magnetic, TOF and calorimetric measurements
Beam monitor
Drift chamber
~ 1.5 m
Start
counter
DE/DX & TOF measurement
Plastic scint
Drift Chamber
Permanent
Magnet (0.8 T)

9. Interaction region Silicon Pixel Vertex Detector Permanent
Magnet (0.8 T)
C or CH2 Target
Permanent
Magnet (0.8 T)
0.75 cm
Silicon Pixel
Vertex Detector
0.75 cm

10. Hallbach geometry for Magnet
Hallback geometry provides uniform transverse magnetic field in a cylindrical geometry: B field proportional to ln(Rout/Rin)
B=0.8T
Thick=8cm
Rin=3.5 cm

11. Complementary approach for the measurement of light fragments
P and He fragments are emitted with a broader angular distribution with respect to heavier fragments
P and He fragment can have long range, can easily punch through the calorimeter
Difficult to cover all Z,A with a single detector design
In order to contain light fragments calorimeter should be quite thick: if a separate system can be used for lighter Z fragments we can build a cheaper absorption detector
Complementary equipment to be inserted between target and magnet for low Z fragments:
Emulsion Cloud Chamber

12. Courtesy of G. De Lellis

13. ECC structure ECC structure: Not homogeneous structure
6 consecutive emulsion films
56 nuclear emulsion layers (300 m) interleaved with 56 lead plates (1 mm)
12.5cm
10.2cm
film 62
6 consecutive emulsions
film 57
film 56
1 mm lead layer
300 μm nuclear emulsion
film 2
film 1

14. Beam exposure of ECC test to be proposed @CNAO
30°≤ α ≤ 90°
Beam (p or C-12)
PMMA
ECC

15. N.B. Emulsion can track light ions at large angle, up to tgθ ~ 3
Courtesy of G. De Lellis

16. Beams & Facilities
Possible facility: CNAO, HIT, HIMAC, GSI, BNL, (LNS)
CNAO: Experimental room would be ok: 16O beam would be necessary
GSI : uncertain (NO) beam availability
HIT: ~ok, experimental room a bit small
HIMAC, BNL : ok, but expensive and with logistic difficulties
MED-AUSTRON ?? Not yet explored, could be an opportunity
LNS : ok for low energy (80 MeV/nucl)
Time schedule for data taking:

17. Other proposal: Aachen experiment
Experimental tests performed at the Cooler Synchrotron (COSY) facility

18. Other possible future experiments about fra gmentation
A big question mark on the possibility of the carbon beam at Archede

19. Altra proposta INFN correlata con FOOT
MoVe IT: Modeling and Verification for Ion beam Treatment planning
Project to coordinate INFN expertise in the field of modeling and radiobiology for exploiting this information in producing advanced, biologically adapted treatment planning, and new devices for its verification.
New implementations in the TPS involve target fragmentation, radiobiological effectiveness (RBE) and treatment of intra-tumor heterogeneity, such as hypoxia.
Output of the project, beyond scientific publications, will be permanent infrastructures in INFN-LNS, CNAO, and TIFPA, novel TPS software algorithms, and patented irradiation devices.
XPR
Trento, Napoli, LNS, Torino, Milano, CNAO