Zanini_BNCT.ppt

[email protected] - April 18th, 2005 1

Boron Neutron Capture Therapy:

tecnica e sorgenti

Alba Zanini


What’s BNCT

Boron Neutron Capture Therapy is a binary form of cancer therapy

It uses a boron-containing compound that preferentially concentrates in tumor sites

BPA Boronophenylalanine

BSH Sulfhydryl borane

The tumor site is irradiated by a neutron

beam

Neutrons interact with the boron in the tumor

damage is done to the tumor cell

10B 1n 11B* 7Li 4He

-photon


Emission of high LET and low range ions :

4He2+ (9 m) 7Li3+ (6 m)

• These ranges are comparable with the average cell diameter.

• The ionizations are responsible of the DNA double strand break and this effect is lethal at this effect is lethal at least in 95% of cases.least in 95% of cases.

10B (n,) 7Li10B + nth 11B* 7Li (1.01 MeV) + (1.78 MeV) (6 %)

10B + nth 11B* 7Li (0.84 MeV)+ (1.47MeV) + (0.48 MeV) (94 %)

BNCT Cell-killing mechanism(1.47 MeV)

(0.84 MeV)

(0.48 MeV)


Patologies treated with BNCT neutron source: REACTOR

Epithermal neutron to treat:

Brain tumour

• Fir-1 Espoo Helsinki, Finland;

• Massachusetts Institute of Technology;

• Brookhaven National Laboratory;

• Studsvik, Sweden;

• High Flux Reactor Petten, Netherlands;

Head and Neck tumour

• Kyoto University Reasearch Reactor, Japan

Thermal neutron to treat

Melanoma

• Massachusetts Institute of Technology;

• RA-6 Reactor at the Bariloche Atomic Center Buenos Aires, Argentina

Explanted Liver

• Triga Mark II reactor Pavia, Italy


Novel neutron sources for BNCT

• Reactors are large, expensive and subject to strict regulations, making them unsuitable for in-hospital treatment.

Disadvantages of nuclear reactors

• Charged-particle accelerators,

• compact neutron generators

• LINAC accelerator for radiotherapy (PHONES, INFN project).

SEARCH for in-hospital neutron sources:


Innovative Neutron Sources for in-hospital treatment

Compact neutron generator based on D-D or D-T fusion reaction.

Collaborations with Lawrence Berkeley National Laboratory (CA, USA), EUROSEA (To), S. Giovanni A. S. Hospital (To)

Phononeutron reaction (,n) in linear accelerator head.

Collaborations with INFN Trieste, Gemelli Hospital (Roma)


BSA and figures of merit

Thermal neutrons are nedeed for surface treatment (En < 0.04 eV)

Epithermal neutrons are nedeed for in depth treatment (0.04 eV< En < 10 keV) such as brain tumour.

epith [cm-2 s-1] 1E8-1E9

Df / epith [Gy cm2] < 2E-13

D /epith [Gy cm2] < 2E-13

Free beam parameters; IAEA recommended values

Beam Shaping Assembly

Study of different materials and

thicknesses in order to optimize the neutron

energy spectrum delivering highest dose

to the tumour and minimizing undesired

dose to patient’s body.

Zanini_BNCT.ppt

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