High spatial resolution microdosimetry with monolithic Delta E-E detector on C-12 beam: Monte Carlo simulations and experiment

Nuclear fragmentation produced in 12C ion therapeutic beams contributes significantly to the Relative Biological Effectiveness (RBE)—weighted dose in the distal edge of the Spread out Bragg Peak (SOBP) and surrounding tissues in out-of-field. Complex mixed radiation field originated by the therapeutic 12C ion beam in a phantom is difficult to measure. This study presents a new method to characterise the radiation field produced in a 12C ion beam using a monolithic Delta E-E telescope which provides the capability to identify the particle components of the mixed radiation field as well as the microdosimetric spectra that allows derivation of the RBE based on a radiobiological model.