A project aimed at the development of an accelerator facility devoted to Boron Neutron Capture Therapy (BNCT) is ongoing at the National Atomic Energy Commission of Argentina. In a first stage of development, the accelerator will be capable of delivering proton or deuteron beams of 30 mA at about 1.4 MeV which is suitable for neutron production through the ⁹Be(d,n) reaction. In this context, deep-tumor treatment capabilities of neutron beams produced by this reaction have been thoroughly studied in the last few years. Our previous studies based on a Snyder head phantom showed very encouraging results for a neutron field produced by bombarding a thin Be target (8 mm) with a 30 mA beam of 1.45 MeV deuterons.
In this work we evaluate the performance of the proposed neutron source for the treatment of a real patient with diagnosed glioblastoma multiforme (GBM). The patient's head with a 4.2 cm³ tumor within the occipital lobe of the brain was modeled by 11025 voxels from a computed tomography stack. The absorbed dose rate was computed via the Monte Carlo N-Particle code (MCNP) and the neutron beam direction was determined based on the location of the lesion using the NCTPlan code, a treatment planning code widely used in BNCT. The results derived from the simulations were assessed prescribing 11 Gy-Eq as the peak dose to normal brain, according to clinical protocols.
Preliminary results show that a significant peak dose of 47 Gy-Eq can be delivered to the tumor with the proposed scheme in a single-field irradiation of 60 minutes while keeping the average whole brain dose lower than 4 Gy-Eq. These results are comparable to those obtained with the ⁷Li(p,n)⁷Be reaction, which provides a better quality neutron field for BNCT. Moreover, the dose performances obtained with the proposed neutron source are comparable to those achieved in reported phase I/II clinical trials.
These promising results strengthen the prospects for a potential use of the ⁹Be(d,n)¹⁰B reaction for BNCT brain tumor treatments and for the implementation of an operational AB-BNCT facility in Argentina in the relatively short term.