Analysis of the Influence of Boron Distribution on Compound Biological Effectiveness Values in Boron Neutron Capture Therapy.

Abstract

Boron neutron capture therapy (BNCT) is an innovative cancer treatment that uses the ¹⁰B(n,α)⁷Li reaction to selectively destroy cancer cells at the cellular level. In BNCT, the biological effectiveness of boron doses is typically assessed using the compound biological effectiveness (CBE) factor. This study analyzes the impact of boron distribution on CBE values based on the microdosimetric kinetic model and Monte Carlo simulations. Simulations were conducted on both macroscopic and microscopic scales. At the macroscopic level, the average dose absorbed by cells within tissues was modeled, whereas at the microscopic level, the microdosimetric lineal energy spectra and the microscopic dose absorbed by cell nuclei were simulated. The CBE values for various cells during BNCT were then derived from the Monte Carlo simulation data. Results indicate that although macroscopic boron concentrations had no significant impact on CBE values, the distribution of boron at the cellular level played a crucial role; CBE values increased as boron moved closer to the cell nucleus. This study proposes a method for calculating CBE values using Monte Carlo simulations, providing insights for evaluating CBE values and developing novel boron agents for BNCT.