Secondary radiation measurements for particle therapy applications: Nuclear fragmentation produced by 4He ion beams in a PMMA target
Nowadays there is a growing interest in particle therapy treatments exploiting
light ion beams against tumors due to their enhanced relative biological
effectiveness and high space selectivity. In particular promising results are
obtained by the use of 4He projectiles. Unlike the treatments performed
using protons, the beam ions can undergo a fragmentation process when
interacting with the atomic nuclei in the patient body. In this paper the results
of measurements performed at the Heidelberg Ion-Beam Therapy center are
reported. For the first time the absolute fluxes and the energy spectra of the
fragments—protons, deuterons, and tritons—produced by 4He ion beams of
102, 125 and 145 MeV u?1 energies on a poly-methyl methacrylate target
were evaluated at different angles. The obtained results are particularly
relevant in view of the necessary optimization and review of the treatment
planning software being developed for clinical use of 4He beams in clinical
routine and the relative bench-marking of Monte Carlo algorithm predictions.