研究実績の概要 |
The original design of the study was modified to use accelerator-based neutron irradiation and gold nanoparticles combined with boron compounds for boron neutron capture therapy (BNCT). T98G cells were incubated with 0, 10, 20, or 40 ppm of BPA or boric acid and 50 nm gold nanoparticles to evaluate the absorbed neutron dose in the samples. The cells were placed in a phantom made of organic glass under the lithium target of the proton accelerator and irradiated for 1-2 hours with 2.0-2.3 MeV proton energy, 1-3 mA proton current, and 50-300 million events of epithermal neutron generation. The activation of gold in the samples was measured using a gamma spectrometer. The accumulation of gold in the cells was observed by electronic microscopy and measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The boron dose was estimated by Monte Carlo simulation from gold nanoparticle activation data. The cell survival data confirm the efficacy of the proton accelerator with the lithium target to produce a sufficient number of neutrons to initiate the boron neutron capture reaction within and close to tumor cells. The new approach in dosimetry for BNCT in the current study may allow us to determine the absorbed neutron dose using combined boron compounds containing an additional high-Z element. This approach may open up a new perspective in boron compound distribution and treatment efficacy evaluation that may lead to modification of such methods as isotope scanning and positron emission tomography (PET).
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