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Seche, E ; Sabattier, R ; Bajard, JC ; Blondiaux, G ; Breteau, N ; Spotheim-Maurizot, M ; Charlier, M

Direct effect in DNA radiolysis. Boron neutron capture enhancement of radiolysis in a medical fast-neutron beam

Radiation Research 158 (3) 292-301

par Administrateur - publié le

Abstract :

This paper is devoted to the study of the molecular basis of the boron neutron capture enhancement of fast-neutron radiotherapy. Plasmid DNA was irradiated with a medical fastneutron beam in the presence of either B-10 or B-11. The number of induced SSBs and DSBs was much higher in samples containing B-11 compared to B-11. The additional breaks are attributed to the nuclear reaction B-10(n, alpha)Li-7 induced by the capture by B-10 of thermal neutrons produced in the medium by scattering and slowing down of neutrons. Irradiation in the presence of DMSO (OH radical scavenger) allows the number of nonscavengeable breaks to be determined. The ratio DSB/SSB, is within the range of those observed with heavy ions, in good agreement with the hypothesis that the additional breaks are due to alpha particles and recoil lithium nuclei.