1. Construction of a convenient head phantom for BNCT experiments in Tehran research reactor
E. Bavarnegin,Yaser Kasesaz, H. Khalafi
Nuclear Science and Technology Research Institute, Iran
I due argomenti trattati in questa tesina sono un breve review sulle motivazioni fisiche e la storia dell’adroterapia e una presentazione dei recenti progressi e delle nuove prospettive soprattutto in Italia.

2. BNCT – physical background
Per capire cos’è l’adroterapia bisogna illustrare cos’è la radioterapia: essa consiste nell’irraggiare con radiazioni o particelle ionizzanti individui colpiti da tumore per inattivare o distruggere le cellule neoplastiche risparmiando per quanto possibile il tessuto sano circostante. Praticamente fino allo scorso decennio la terapia radiante era effettuata prevalentemente con fotoni (raggi X o raggi gamma) e più limitatamente con elettroni.

3. Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba
BNCT beam parameters
BNCT with epithermal neutron beam
In air beam parameters
BNCT with Thermal neutron beam
Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba

4. TRR irradiation facilities
- TRR is a 5 MW MTR (Material Test Reactor)
- pool type research reactor
- Its fuel assemblies contain low enriched uranium fuel
- plates in the form of U3O8 Al alloy
- The reactor pool has two major parts, a stall-end and an open pool.
- The reactor core can operate in both parts of the pool for different purposes.

5. Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba
Thermal column of Tehran research reactor is feasible for BNCT.
Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba

6. Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba
Dosimetry in BNCT
BNCT beam parameters
In phantom parameters
The main purpose of phantom dosimetry is to measure the neutron and gamma fluence rate and absorbed dose distributions. Phantom dosimetry provides information, which can be used to verify a neutron beam.
Advantage Depth (AD)
Advantage Depth Dose Rate (ADDR)
Therapeutic Time (TT)
Therapeutic Gain (TG)
Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba 6

7. Main dose components in BNCT
Neutron reactions in tissue :
Thermal Neutrons:
Epithermal and fast neutrons:
1H(n,)2H
Gamma dose
14N(n,p)14C
Nitrogen dose
10B(n,α)7Li
Boron dose
Elastic scattering mainly with H
(backscattering p+ )
Per capire cos’è l’adroterapia bisogna illustrare cos’è la radioterapia: essa consiste nell’irraggiare con radiazioni o particelle ionizzanti individui colpiti da tumore per inattivare o distruggere le cellule neoplastiche risparmiando per quanto possibile il tessuto sano circostante. Praticamente fino allo scorso decennio la terapia radiante era effettuata prevalentemente con fotoni (raggi X o raggi gamma) e più limitatamente con elettroni.
Fast neutron dose
Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba

8. Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba
BNCT phantom
One of the requirements for BNCT at a nuclear research reactor is
construction of a phantom and measurements of physical dose distribution, Off-axis profiles, etc.
Therefore:
We have designed and constructed a head phantom for BNCT
experiments of Tehran research reactor
Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba

9. Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba
BNCT phantom
Characteristics of our designed head phantom for TRR BNCT experiments
The shape and dimension is close to a standard head model ( Snyder head model).
The materials are neurotically similar to the tissue
The design permits us the determination of all relevant doses at many location inside of the phantom. So the 3D dose- map can obtain.
There are places for dosimetric devices like gold foils, TLD and …
Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba

10. Design of TRR BNCT head phantom
An ellipsoidal acrylic walled anthropomorphic head phantom.
Dimensions are close to the Snyder head model.
Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba

11. Design of TRR BNCT head phantom
Acrylic base
An acrylic base was attached to the shell of the phantom
In order to insertion of detectors into the phantom volume, 31 ports were assumed in the phantom base.
ports
One port on the phantom center line and the others each on three concentric circles of 3.4, 6.2 and 9 cm diameter.
Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba

12. Design of TRR BNCT head phantom
point dose measurement devices, like ion chambers and gold foils can be held in position with an acrylic spacer at the end of tubes which can be inserted from the ports into the phantom volume.
Water was chosen for the interior of the phantom.
Place of TLDs and gold foils.
Side view of the phantom
Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba

13. Design of TRR BNCT head phantom
Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba

14. MCNP geometry of designed phantom
The thermal column of Tehran research reactor can be also a favorable facility for providing an epithermal neutron beam for BNCT.

15. Thermal neutron beam of TRR
Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba

16. Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba

17. Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba

18. Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba
Thermal column of TRR
Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba

19. Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba

20. Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba

21. Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba

22. Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba
Designed head phantom in front of the simulated epithermal neutron beam of TRR
Tallies
MCNP geometry,
(1) Core, (2) Pb block, (3) Al-caned graphite box, (4) Moderator, (5) air filled collimator, (6) Pb Reflector, (7) Bi gamma shield, (8) Cd filter, (9) Designed phantom,(10) water,(11) acrylic.
Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba

23. Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba
In phantom parameters for simulated epithermal neutron beam of TRR
Facility
ADDR
(cGy/min) AD
(cm) TT
(min)
Tumor: normal tissue 10B concentration (ppm)
THOR 50
8.9 25
65:18
FiR-1 45 9 30
R2-0 67
9.7 20
TRR 49
7.5
Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba

24. THANKS FOR YOUR KIND ATTENTION!!!
Per capire cos’è l’adroterapia bisogna illustrare cos’è la radioterapia: essa consiste nell’irraggiare con radiazioni o particelle ionizzanti individui colpiti da tumore per inattivare o distruggere le cellule neoplastiche risparmiando per quanto possibile il tessuto sano circostante. Praticamente fino allo scorso decennio la terapia radiante era effettuata prevalentemente con fotoni (raggi X o raggi gamma) e più limitatamente con elettroni.
Prof. Mauro Valente - CONICET & Universidad Nacional de Cordoba 24