Boron neutron capture therapy (BNCT) is an experimental treatment modality which depends on a sufficient cellular uptake of Boron ((10)B) followed by an exposure to a thermal neutron beam from a nuclear reactor. High energetic particles (4He and 7Li) are created during the neutron capture reaction and produce DNA damages, which lead to cell killing. Regarding BNCT, the short radiation range of He- and Li-particles is decisive for the distribution of (10)B. Until now, BNCT has been lacking for therapeutically effective concentrations of (10)B. Twenty-four hours after the combined use of our 'Bioshuttle'-p-borono-phenylalanine(10)-constructs ('Bioshuttle'-p-BPA(10)) and neutron-irradiation, an obvious reduction of the radiation-resistant HeLa-S cells could be observed. No cells were alive 72 h after the incubation with 'Bioshuttle'-p-BPA(10) followed by neutron irradiation. A post-mitotic cell death could be assumed based on flow cytometrical data.