Research on the dose calculation of BNCT based on the time-varying boron concentration in pharmacokinetics

Boron Neutron Capture Therapy (BNCT) is a targeted radiotherapy that utilizes the nuclear reaction of 10B with thermal neutrons to destroy tumor cells while sparing healthy tissue. Its effectiveness relies on accurately modeling boron distribution. Current treatment planning systems use a fixed tumor-to-normal tissue (T/N) boron ratio, ignoring pharmacokinetics. This study improves BNCT dose calculations by integrating time-dependent boron concentrations from pharmacokinetic simulations. Firstly, this research improved the traditional two-compartment pharmacokinetic model to a three-compartment model to better represent boron distribution, accounting for different tumor locations. Two patient cases were simulated, and the comparisons were performed between the dose distributions obtained by the fixed T/N ratio method and the ones obtained by our pharmacokinetic-based approach. Results showed significant discrepancies between the two methods, with the maximum dose deviation in the tumor region reaching 11.386%. The pharmacokinetic-based method provided more accurate and individualized dose calculations. Secondly, the multi-objective optimization using the Basin Hopping algorithm was employed to determine the optimal irradiation time periods. This approach enhanced treatment efficacy by increasing the average dose and maximum dose in the gross tumor volume by ~4% within the same irradiation period, while minimizing damage to normal tissues. The optimized irradiation schedules resulted in improved dose delivery to the tumor while maintaining safe levels for normal tissues. Our findings highlight the importance of integrating pharmacokinetic data into BNCT treatment planning to improve dose accuracy and treatment outcomes.