Computational assessment of deep-seated tumor treatment capability of the 9Be(d,n)10B reaction for accelerator-based Boron Neutron Capture Therapy (AB-BNCT)

Authors:   Capoulat M. E., Minsky D. M., Kreiner A. J.
Journal: Physica Medica
https://dx.doi.org/10.1016/j.ejmp.2013.07.001
Abstract: The 9Be(d,n)10B reaction was studied as an epithermal neutron source for brain tumor treatment through Boron Neutron Capture Therapy (BNCT). In BNCT, neutrons are classified according to their energies as thermal (<0.5eV), epithermal (from 0.5eV to 10keV) or fast (>10keV). For deep-seated tumors epithermal neutrons are needed. Since a fraction of the neutrons produced by this reaction are quite fast (up to 5-6MeV, even for low-bombarding energies), an efficient beam shaping design is required. This task was carried out (1) by selecting the combinations of bombarding energy and target thickness that minimize the highest-energy neutron production; and (2) by the appropriate choice of the Beam Shaping Assembly (BSA) geometry, for each of the combinations found in (1). The BSA geometry was determined as the configuration that maximized the dose deliverable to the tumor in a 1h treatment, within the constraints imposed by the healthy tissue dose adopted tolerance. Doses were calculated through the MCNP code.The highest dose deliverable to the tumor was found for an 8μm target and a deuteron beamof1.45MeV. Tumor weighted doses ≥40Gy can be delivered up to about 5cm in depth, withamaximum value of 51Gy at a depth of about 2cm. This dose performance can be improved byrelaxing the treatment time constraint and splitting the treatment into two 1-h sessions. Thesegood treatment capabilities strengthen the prospects for a potential use of this reaction in BNCT.