Advances of LINAC-based boron neutron capture therapy in Korea

Boron neutron capture therapy (BNCT) has been attracting interest as a new radiation modality for cancer therapy because it can selectively destroy cancer cells while maintaining the healthy state of surrounding normal cells. Many experimental trials have demonstrated significant BNCT treatment efficacy using neutron beams from research reactors. However, nuclear reactor technology cannot be scaled to sites in hospitals delivering patient treatment. Therefore, compact accelerator-based neutron sources that could be installed in many hospitals are under development or have even been commissioned at many facilities around the world. In Korea, a radio-frequency (RF) linac-based BNCT (A-BNCT) facility is under development by DawonMedax (DM). It provides the highly efficient production of an epithermal neutron beam with an optimized neutron energy spectrum range of 0.1~10 keV. With a 2-mA 10-MeV proton beam from the accelerator, the irradiation port epithermal neutron flux is higher than 1 × 10⁹ n/cm²⋅s. Comprehensive verification and validation of the system have been conducted with the measurement of both proton and neutron beam characteristics. Significant therapeutic effects from BNCT have been confirmed by DM in both in vitro and in vivo non-clinical trials. Further, during exposure to epithermal neutrons, all other unintended radiation is controlled to levels meeting International Atomic Energy Agency (IAEA) recommendations. Recently, the Korean FDA has accepted an investigational new drug (IND) and the first-in-human clinical trial of BNCT is now being prepared. This paper introduces the principles of BNCT and accelerator-based neutron sources for BNCT and reports the recent advances of DM A-BNCT facility which is the main part of this paper.