Thermal neutron (n (thermal))

A thermal neutron is a free neutron that has been slowed down to thermal equilibrium with its environment, typically possessing a kinetic energy of approximately 0.025 eV (Barth et al., 2012). In medical science, thermal neutrons are not biological targets such as receptors or enzymes, but rather serve as the external physical trigger for Boron Neutron Capture Therapy (BNCT) (IAEA, 2001). BNCT is a binary treatment modality where a boron-10 isotope is delivered to tumor cells via specialized carriers, followed by irradiation with a thermal neutron beam (Barth et al., 2012; Sauerwein et al., 2012). When a thermal neutron is captured by a boron-10 nucleus, it undergoes a nuclear reaction producing high-energy alpha particles and lithium-7 nuclei (Sauerwein et al., 2012). These particles have a very short range in tissue (5-9 micrometers), which is approximately the diameter of a single cell, allowing for highly localized destruction of tumor cells while sparing surrounding healthy tissue (Barth et al., 2012; Moss, 2014). Consequently, the thermal neutron acts as a catalyst for localized radiotherapy rather than a traditional pharmacological ligand (IAEA, 2001). This approach is primarily investigated for the treatment of invasive tumors such as glioblastoma multiforme and recurrent head and neck cancers (Barth et al., 2012).

Other names

Slow neutronLow-energy neutron

Thermal neutron capture by Boron-10 isotopes, leading to the emission of high-energy alpha particles and lithium-7 nuclei that induce localized cellular damage (Barth et al., 2012; Sauerwein et al., 2012).