Neutron Source For Neutron Capture Therapy Of Cancer

Neutron Source For Neutron Capture Therapy Of Cancer Tissues At Kyiv Research Reactor STCU Workshop "From Science to Business" 11 – 12 October 2006, Kyiv Olena GRITZAY Tel 380 44 5253987 ogritzay@kinr. kiev. ua Institute for Nuclear Research NAS Ukraine Kyiv 1

Today NCT is a promising form of radiation therapy. It includes 2 interconnected features: • the infusion or delivery of a capture compound, which preferentially concentrates in the tumor, • then the irradiation of the tumor site by neutrons. As the isotope B-10 is often used as the neutron capture agent, in this case NCT is called Boron Neutron Capture Therapy (BNCT). 2

Why 10 B? The large cross section of thermal neutron interactions with B-10 isotope ( th 4 000 barn) causes high probability of a slitting of boron nucleus onto He and Li. As ionization capability of He and Li ions is high, and their runs are short, then the cells, preferably enriched by boron, are killed and the healthy cells are damaged much less. 3

Thermal neutrons? No. Why? Tumor (in brain) is located on depths 3 -10 cm. nth • low penetrating capability • high skin dose The most suitable neutrons for BNCT are neutrons with energy in the region from 1 e. V to 10 ke. V (epithermal), because their direct tissue damage is smaller than for thermal or fast neutrons. Such epithermal neutron beams may be formed at nuclear 4 research reactors.

No necessity to build a new reactor, because the ready-made one may be used after reconstruction that does not touch on basic functional modules The concept of the source consists in transformation of the reactor radiation into epithermal radiation. 5

BNCT facility in world Facility HFR MITR-II BMRR (Petten) (USA) … KRR (Kyiv) Power (MW) Status 3 … 10 plan … ? 45 3 operated 6

Stage of Development: Calculations have shown that an epithermal neutron source, which meets requirements of BNCT, can be constructed at the Kyiv research reactor by means of replacement of materials filling thermal column with special composition. Neutron filter of Ni-60 can essential improve therapeutic source parameters. 7

KRR Thermal Column Reconstruction 2 1 • I – TC (untill reconstruction): A– the first block, B– the second block. 3 4 I A B D 3 5 D 1 6 380 II • II – Geometry for MCNP calculations (vertical cross section through the core center) 108 1 2 3 4 5 6 7 8 8 D 2

Advantages of BNCT method: • a possibility to destroy tumors without highly traumatic surgical operation • a possibility to give high radiation doses in malignant cells and at that do not destroy healthy ones 9

Areas of Applications: • oncology, especially treating tumors in brain • veterinary medicine 10

Contact information Olena Gritzay Tel 380 44 5253987 ogritzay@kinr. kiev. ua Institute for Nuclear Research NAS Ukraine Kyiv Technology Reference: Alexander Sich alex. sich@stcu. int 11