Boron Neutron Capture Therapy (BNCT)

Boron Neutron Capture Therapy (BNCT) is a binary radiotherapy modality that combines the principles of targeted drug delivery with neutron irradiation to selectively destroy cancer cells[1][5]. The therapy operates through a two-step process: first, a boron-10 containing compound is administered to the patient, which selectively accumulates in tumor cells; second, the target area is irradiated with low-energy thermal neutrons or epithermal neutrons that become thermalized in tissue[5][8]. The therapeutic effect relies on the nuclear capture reaction that occurs when boron-10 atoms capture thermal neutrons, resulting in the formation of unstable boron-11 which immediately undergoes nuclear fission to produce high-energy alpha particles (helium-4) and recoil lithium-7 nuclei[1][3]. These particles have high linear energy transfer (LET) properties and very short path lengths (5-9 micrometers, approximately the diameter of a single cell), allowing them to deposit their destructive energy primarily within the boron-containing tumor cells while sparing adjacent normal tissue[6][9]. The effectiveness of BNCT depends critically on achieving sufficient boron-10 concentration in tumor cells (typically 20-50 μg boron-10 per gram of tumor) and favorable tumor-to-normal tissue concentration ratios (>3-4:1)[5]. The two boron delivery agents most commonly used in clinical settings are boronophenylalanine (BPA) and sodium borocaptate (BSH), though research continues to develop more effective delivery systems with higher boron content and improved tumor selectivity[5][9]. BNCT has been used to treat various malignancies including high-grade gliomas, recurrent head and neck cancers, melanomas, and hepatocellular carcinoma[1][5]. As of 2023, clinical implementation remains limited, with availability primarily in Japan[10]. Ongoing research focuses on developing more efficient boron delivery agents, optimizing neutron sources (shifting from nuclear reactors to accelerator-based systems), and expanding clinical applications to other cancer types[2][3].

Other names

Boron-10 nuclear captureNeutron capture therapy of cancer (NCT)Boron neutron capture therapeutics

BNCT's mechanism of action involves the nuclear capture and fission reaction of boron-10 atoms with thermal neutrons. This reaction generates high linear energy transfer (LET) alpha particles and produces recoil lithium-7 nuclei. These high-energy particles then induce DNA double-strand breaks, primarily within the boron-containing tumor cells.