Neutron Capture Enhanced Particle Therapy (NCEPT) is a novel approach to nuclear medicine that utilises neutron capture agents (NCAs – biologically inert compounds bearing 10B or 157Gd) to enhance the efficacy of charged particle therapy by leveraging the neutron cloud produced around the target site upon irradiation. NCAs capture these neutrons, then emit short range, high energy radiation, providing a highly localised dose to the target tissue. In effect, this approach is a temporally and spatially targeted radionuclide therapy, activated ‘on-demand’ within the patient by particle radiation, improving treatment selectivity and outcomes. This discovery presents an exciting new field of drug development for cancer.
Results of in vitro experiments performed with carbon and helium ion beams and two representative NCAs (10B-BPA and 157Gd-DOTA-TPP) show a dose dependent reduction in T98G glioblastoma cell viability for cells exposed to 3Gy of particle radiation and increasing NCA concentration. Cells immediately adjacent to the beam (no particle radiation, but still within the neutron cloud) also experienced reduced viability when they were treated with a neutron capture agent, showing that neutron capture was responsible for a great deal of the cell death.
Our group has recently performed in vivo studies on a U87MG glioblastoma xenograft mouse model, which showed a significant delay in tumour growth and reduction in volume for mice treated with BPA and Carbon ion radiation. Most excitingly, these results were replicated across repeat studies.
These in vitro and in vivo experiments with a commercially available neutron capture agent (BPA) provide a foundation for the development of other drug classes as NCAs (Figure 1E). This talk will discuss in further detail the promising results we have observed from NCEPT to date, and current efforts in our NCA development projects.