Present Status Of Accelerator-Based Bnct

Aim: This work aims at giving an updated report of the worldwide status of Accelerator-Based BNCT (AB-BNCT).Background: There is a generalized perception that the availability of accelerators installed in hospitals, as neutron sources, may be crucial for the advancement of BNCT. Accordingly, in recent years a significant effort has started to develop such machines.Materials and methods: A variety of possible charged-particle induced nuclear reactions and the characteristics of the resulting neutron spectra are discussed along with the worldwide activity in suitable accelerator development.Results: Endothermic Li-7(p,n)Be-7 and Be-9(p,n)B-9 and exothermic Be-9(d,n)B-10 are compared. In addition to having much better thermo-mechanical properties than Li, Be as a target leads to stable products. This is a significant advantage for a hospital-based facility. Be-9(p,n)B-9 needs at least 4-5 MeV bombarding energy to have a sufficient yield, while Be-9(d,n)B-10 can be utilized at about 1.4 MeV, implying the smallest possible accelerator. This reaction operating with a thin target can produce a sufficiently soft spectrum to be viable for AB-BNCT. The machines considered are electrostatic single ended or tandem accelerators or radiofrequency quadrupoles plus drift tube Linacs.Conclusions: Li-7(p,n)Be-7 provides one of the best solutions for the production of epithermal neutron beams for deep-seated tumors. However, a Li-based target poses significant technological challenges. Hence, Be has been considered as an alternative target, both in combination with (p,n) and (d,n) reactions. Be-9(d,n)B-10 at 1.4 MeV, with a thin target has been shown to be a realistic option for the treatment of deep-seated lesions. (C) 2014 Greater Poland Cancer Centre. Published by Elsevier Sp. z o.o. All rights reserved.