Spectral performance of a composite single-crystal filtered thermal neutron beam for BNCT research at the University of Missouri

Boron neutron capture therapy demonstrated in mice bearing EMT6 tumors following selective delivery of boron by rationally designed liposomes

“…Our continued progress was impeded only by the lack of access to an appropriate neutron source with which to perform therapeutic efficacy trials. The construction of a thermal neutron beam line at the University of Missouri Research Reactor has now permitted us to conduct these critical investigations (36).…”

“…Dose-limiting side effects have been encountered in several human and animal trials of BNCT that could at least in part be attributed to the relatively high relative biological effectiveness of the background epithermal, fast neutron, and γ-spectral components of the neutron beams (38). The thermal neutron beam constructed for our BNCT studies possesses minimal γ-and fast neutron contamination (36).…”

Validation and Comparison of the Therapeutic Efficacy of Boron Neutron Capture Therapy Mediated By Boron-Rich Liposomes in Multiple Murine Tumor Models

“…Cu/Au flux wires were affixed to the right or left flank (over the tumor) using tape before it was placed in a positioning gantry as described previously by Kueffer et al [38] The average neutron flux was previously determined to be 8.8 x 10 8 neutrons/cm 2 s (±7%) integrated over the (thermal) energy range of 0.0 to 0.414 eV. The neutron spectrum validation has previously been described by Brockman et al [14] Irradiation times varied from 30 to 90 minutes, and doses were determined using the sum of dose components from Table 1 . After the irradiation procedure, mice were monitored with daily tumor measurements until humane endpoints were met.…”

“…The total physical dose delivered in a BNCT treatment is the sum of all of the physical dose components [10] . Based on the beam characteristics as shown in Table 1 , there are two variables that determine total dose delivered to a tissue: the tissue boron concentration and the time length of irradiation [14] . The total biologic effective dose is much more complex, and must be determined experimentally with very specific endpoints [15] .…”

“…While most BNCT facilities still use a nuclear reactor as a neutron source, filtering methods have improved since the initial investigations into this therapy. These advances have resulted in improved neutron spectra, allowing reduced gamma and fast neutron dose components, as well as the use of epithermal neutrons to allow for deeper penetration into tissues and skin sparing [14] , [29] , [30] , [31] . Currently, there remains a need for new boron-delivery compounds and a critical assessment of clinical uses.…”