Overview of Boron Neutron Capture Therapy in 2022.

In April 2022, the National Cancer Institute of the United States organized a 3-day seminar, dedicated to boron neutron capture therapy (BNCT). This short article summarizes a presentation from that event, which is intended to provide an overview of activities currently underway worldwide to make BNCT available for patient treatments. This overview does not claim to be exhaustive but shows a great deal of activity in all areas necessary for the complex therapy that is BNCT. A rapid increase in the number of BNCT centers can be expected over the next few years, coupled with the introduction of novel drugs for BNCT. It will be a major challenge to all stakeholders to create clinical networks that can conduct the necessary prospective clinical trials in a short time and in high quality.

Importance of radiobiological studies for the advancement of boron neutron capture therapy (BNCT).

Boron neutron capture therapy (BNCT) is a tumour selective particle radiotherapy, based on the administration of boron carriers incorporated preferentially by tumour cells, followed by irradiation with a thermal or epithermal neutron beam. BNCT clinical results to date show therapeutic efficacy, associated with an improvement in patient quality of life and prolonged survival. Translational research in adequate experimental models is necessary to optimise BNCT for different pathologies. This review recapitulates some examples of BNCT radiobiological studies for different pathologies and clinical scenarios, strategies to optimise boron targeting, enhance BNCT therapeutic effect and minimise radiotoxicity. It also describes the radiobiological mechanisms induced by BNCT, and the importance of the detection of biomarkers to monitor and predict the therapeutic efficacy and toxicity of BNCT alone or combined with other strategies. Besides, there is a brief comment on the introduction of accelerator-based neutron sources in BNCT. These sources would expand the clinical BNCT services to more patients, and would help to make BNCT a standard treatment modality for various types of cancer. Radiobiological BNCT studies have been of utmost importance to make progress in BNCT, being essential to design novel, safe and effective clinical BNCT protocols.

Simulation study of accelerator based quasi-mono-energetic epithermal neutron beams for BNCT.

Filtered neutron techniques were applied to produce quasi-mono-energetic neutron beams in the energy range of 1.5-7.5 keV at the accelerator port using the generated neutron spectrum from a Li (p, n) Be reaction. A simulation study was performed to characterize the filter components and transmitted beam lines. The feature of the filtered beams is detailed in terms of optimal thickness of the primary and additive components. A computer code named "QMNB-AS" was developed to carry out the required calculations. The filtered neutron beams had high purity and intensity with low contamination from the accompanying thermal, fast neutrons and γ-rays.