Boron Neutron Capture Therapy

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 [1]. 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 μm) 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.