Thermal neutron irradiation field design for boron neutron capture therapy of human explanted liver

The experimental determination of the relative biological effectiveness of thermal neutron factors is fundamental in Boron Neutron Capture Therapy. Present values have been obtained using mixed beams consisting of both neutrons and photons of various energies. A common weighting factor has been used for both thermal and fast neutron doses, although such an approach has been questioned. At the nuclear reactor of the Institut Laue-Langevin a pure low-energy neutron beam has been used to determine thermal neutron relative biological effectiveness factors. Different tumor cell lines, corresponding to glioblastoma, melanoma, and head and neck squamous cell carcinoma, and non-tumor cell lines (lung fibroblast and embryonic kidney) have been irradiated using an experimental arrangement designed to minimise neutron-induced secondary gamma radiation. Additionally, the cells were irradiated with photons at a medical linear accelerator, providing reference data for comparison with that from neutron irradiation. Survival and proliferation were studied after irradiation, yielding the Relative Biological Effectiveness corresponding to the damage of thermal neutrons for the different tissue types.

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Synthesis and Evaluation of Dodecaboranethiol Containing Kojic Acid (KA-BSH) as a Novel Agent for Boron Neutron Capture Therapy

Cells ◽

10.3390/cells9061551 ◽

2020 ◽

Vol 9 (6) ◽

pp. 1551 ◽

Cited By ~ 1

Author(s):

Koji Takeuchi ◽

Yoshihide Hattori ◽

Shinji Kawabata ◽

Gen Futamura ◽

Ryo Hiramatsu ◽

...

Keyword(s):

Tumor Cells ◽

Neutron Irradiation ◽

Boron Neutron Capture Therapy ◽

Neutron Capture ◽

Kojic Acid ◽

Alpha Particles ◽

Neutron Capture Therapy ◽

Survival Times ◽

Boron Neutron Capture ◽

Biodistribution Studies

Boron neutron capture therapy (BNCT) is a form of tumor-cell selective particle irradiation using low-energy neutron irradiation of boron-10 (10B) to produce high-linear energy transfer (LET) alpha particles and recoiling 7Li nuclei (10B [n, alpha] 7Li) in tumor cells. Therefore, it is important to achieve the selective delivery of large amounts of 10B to tumor cells, with only small amounts of 10B to normal tissues. To develop practical materials utilizing 10B carriers, we designed and synthesized novel dodecaboranethiol (BSH)-containing kojic acid (KA-BSH). In the present study, we evaluated the effects of this novel 10B carrier on cytotoxicity, 10B concentrations in F98 rat glioma cells, and micro-distribution of KA-BSH in vitro. Furthermore, biodistribution studies were performed in a rat brain tumor model. The tumor boron concentrations showed the highest concentrations at 1 h after the termination of administration. Based on these results, neutron irradiation was evaluated at the Kyoto University Research Reactor Institute (KURRI) with KA-BSH. Median survival times (MSTs) of untreated and irradiated control rats were 29.5 and 30.5 days, respectively, while animals that received KA-BSH, followed by neutron irradiation, had an MST of 36.0 days (p = 0.0027, 0.0053). Based on these findings, further studies are warranted in using KA-BSH as a new B compound for malignant glioma.

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