Secondary radiation measurements for particle therapy applications: nuclear fragmentation produced by $^4$He ion beams in a PMMA target

TL;DR

This study measures the nuclear fragmentation of $^4$He ion beams in PMMA, providing essential data for optimizing particle therapy treatment planning and benchmarking Monte Carlo simulations.

Contribution

First-time measurement of absolute fluxes and energy spectra of fragments from $^4$He beams in PMMA at multiple energies and angles for therapy applications.

Findings

Fragment fluxes and spectra characterized at various angles.

Data supports optimization of treatment planning software.

Benchmark data for Monte Carlo simulation validation.

Abstract

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 $^4$He 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 $^4$He ion beams of 102, 125 and 145 MeV/u 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 $^4$He beams in clinical routine and the relative benchmarking of Monte Carlo algorithm predictions.