Impact of an External Magnetic Field on Biomaterial Usage in Carbon Ion Therapy for Meningioma

This comprehensive investigation probes the effects of axial magnetic fields on carbon ion therapy, with a focus on biomaterials for cranial substitution in the treatment of meningioma. The study employs validated computational simulations using FLUKA and PHITS Monte Carlo codes to assess dose distribution, secondary neutron production (SNP), and overall therapeutic efficacy under magnetic fields of 0.35T and 1.5T. Distinct biomaterials(PTFE, Alumina, and Ti Alloy)are evaluated for their magnetic responsiveness and dosimetric properties, aiming to optimize treatment outcomes. The simulations reveal that the presence of a magnetic field does not significantly alter the neutron fluence energy distribution within cranial tissues or PTFE, indicating the non-susceptibility of neutrons to magnetic influences. Noteworthy, the study demonstrates a minimal variation in the depth of the Bragg peak for both the cranium and PTFE under 1.5T, with a maximum difference of 2.4mm at 250 MeV/n. In contrast, substantial discrepancies in Bragg peak depths between the cranium and denser materials like Alumina and Ti Alloy are observed, with differences up to 10.8mm, signifying distinct interactions with the magnetic field. These results highlight the potential of PTFE as a promising candidate for cranial reconstruction in MRI-GCIRT, presenting closely matched dose distributions to the cranium and underscoring its suitability for enhancing precision in carbon ion therapy. The findings provide crucial insights for clinical practice, guiding the strategic selection of biomaterials to improve patient outcomes in the treatment of meningioma.