Monte Carlo study of ⁶Li ion irradiation and ¹⁸⁶Re-induced DNA damage

Heavy-ion irradiation has attracted interest because of its favorable energy deposition characteristics, while radionuclide irradiation may provide an additional contribution to heavy-ion irradiation. In this study, we investigated the energy deposition and DNA damage characteristics of ⁶Li ion beams and DNA damage induced by ¹⁸⁶Re decay. We also explored a combined irradiation concept linking external ⁶Li ion irradiation with radionuclide decay. At total kinetic energies of 700-1500 MeV, ⁶Li ions produced Bragg peak depths of 4.66-20.79 cm in a heterogeneous head phantom, covering most target depths considered in the model, with 43-115 double-strand breaks per nucleus. ¹⁸⁶Re decay also produced substantial DNA damage. Because radionuclide use can be limited by supply and availability, we further examined the in-hospital production of ¹⁸⁶Re using a small proton accelerator. Low-energy proton irradiation of tungsten targets produced ¹⁸⁶Re at practically relevant activity levels, supporting the feasibility of this production route. These results connect particle transport, radionuclide decay, DNA damage, and radionuclide production, provide a new framework for exploring combined irradiation approaches, and lay the groundwork for further experimental validation.