Boron Neutron Capture Therapy (BNCT) for Treatment of Multiple Tumor Models

Radiation therapy is the therapeutic modality in which high energy radiations are used to kill tumor cells [1]. Conventional radiation therapy is a whole body radiation process resulting in numerous side effects, highlighting the need to identify alternative targeted therapy [1]. BNCT is a targeted therapy in which cancer cells accumulate boron and are subsequently bombarded with neutrons [2]. During this process, boron accepts the neutron and breaks into two nuclei, Lithium and Helium, releasing energy in the process. The path traveled by the released energy particles is approximately 10 μm in diameter, which is approximately the size of a single cancer cell [3]. The preferential boron accumulation by cancer cells and the short range of energy particles make BNCT a far more targeted therapy than whole body irradiation [3]. As a consequence of its relative specificity, BNCT produces fewer side effects than traditional radiation therapy [4]. One important aspect in the advancement of BNCT is the development of compounds which can deliver a high boron payload to the tumors. Accordingly, Dr. Hawthorne developed compounds Na3[1-(2’B10H9)-2-NH3B10H8] (MAC) and K[nido-7-CH3(CH2)15-7,8C2B9H11] (TAC) that can now deliver high concentration of boron into tumor cells. While other boron compounds had been developed previously, they all suffered from a lack of tumor targetability [5]. To circumvent this decreased targetability, compounds developed by Dr. Hawthorne were engineered such that hydrophobic compound is incorporated into the lipid membrane while the hydrophilic compound is encapsulated within the core of the rationally designed liposomes.