Investigation the potential of Boron neutron capture therapy (BNCT) to treat the lung cancer

Abstract

Introduction: Boron neutron capture therapy (BNCT) is recommended to treat the glioblastoma tumor. It is well known that neuron beams are more effective treatment than photon beams to treat hypoxia tumors due to interaction of neutron with nucleus and production of heavy particles such as 7Li and alpha particle. In this study to evaluate the suitability of BNCT for treating of lung cancer, the dose distributions of neutron beam were calculated in lung tumor volume and in peripheral organs at risk (OARs). Materials and Methods: Dose distribution in Boron neutron capture therapy to treat lung cancer was calculated by MCNPX (2.6.0) code. A 3×3×3 cm3 tumor was located in left lung of ORNL phantom and was irradiated with a rectangular field of neutron positioned at surface source distance (SSD) of 10 cm. recommended spectrum of MIT (Massachusetts Institute of Technology) was used. Tumor was loaded with different concentrations of Boron 0, 10, 30 and 60 ppm. Dose delivered to OARs such as heart, spinal cord, right lung … were calculated. Results: The results show that neutron flux significantly decreased followed to penetrate in lung tissue. Neutron flux decreased in all energy bins of irradiated MIT spectrum; maximum fall- off occurred in the range of epithermal energy. Dose distribution was not depended to SSD. The absorbed dose in tumor was 2.16×10-14, 2.6×10-14, 3.44×10-14 and 4.72×10-14 Gy(per one irradiated neutron from source) for boron concentration of 0, 10, 30 and 60 ppm, respectively. From the OARs, the heart tissue absorbed the maximum dose of 1.66×10-15 Gy (per one irradiated neutron from source). Conclusion: Our simulated model was successful to calculated organ doses in BNCT. As the boron concentration in lung tumor increases, absorbed dose increased while dose uniformity trended downward. Our results show that the MIT neutron source is suitable to treat deep lung tumors while OVRs’ dose maintains within the threshold dose.