Increased cell killing effect in neutron capture enhanced proton beam therapy

Area of Science:

• Oncology
• Medical Physics
• Radiotherapy

Background:

• Proton beam therapy (PBT) generates thermal neutrons.
• Neutron capture reactions with boron are proposed for enhanced PBT (NCEPBT).
• The cell killing effect of NCEPBT requires further investigation.

Purpose of the Study:

• To evaluate the cell killing effect of NCEPBT.
• To determine the impact of boron concentration on NCEPBT efficacy.
• To assess the relative biological effectiveness (RBE) of NCEPBT.

Main Methods:

• Monte Carlo simulations to model neutron distribution.
• Irradiation of human cancer cell lines (HSG, MG63, SAS, G-361) with X-rays, PBT, and NCEPBT.
• Varying boronophenylalanine concentrations (20 and 80 ppm) during NCEPBT.

Main Results:

• Neutrons from PBT were uniformly distributed in simulations.
• NCEPBT with 80 ppm boron showed significantly higher RBE values across all tested cell lines compared to PBT alone.
• RBE values increased with higher boron concentrations, indicating enhanced cell killing.

Conclusions:

• NCEPBT demonstrates an increased cell killing effect, particularly at higher boron concentrations.
• The findings support the clinical potential of NCEPBT.
• Further research into NCEPBT is warranted for its clinical application.