ABSTRACT
These days, externally activated therapies are being envisioned as the future of medicine, mainly cancer therapy [9, 10]. In such therapies, a nontoxic probe (sensitizer) is transformed into a toxic form following irradiation with an external source, such as visible/near-infrared (NIR) light, a magnetic field, X-rays, or thermal neutrons. These sensitizers are first targeted to diseased sites, even though off-target accumulation cannot be completely avoided. However, since the subsequent external radiation is focused only at the diseased site, the toxicity is limited only to the target site, with the probe remaining nontoxic at other, healthy sites. Therefore, such therapies promise to completely avoid off-target toxicity and therapy-related side effects, thus overcoming the major drawbacks associated with conventional therapies. Neutron capture therapy (NCT) was first suggested in 1936 by Locher [11]. BNCT relies on the selective accumulation of boronated sensitizers within tumor tissue, followed by their activation upon irradiation with low-energy neutrons [12]. Specifically, BNCT is based on the nuclear capture and fission reactions that occur when
boron-10 (10B), nonradioactive isotope of boron, is irradiated with low-energy (0.025 eV) thermal neutrons. This resulted in the production of high-linear-energy-transfer (LET) alpha particles (4He) and recoiling lithium-7 (7Li) nuclei, as shown in Fig. 6.1 [13].
