Characterisation of an Accelerator-Based Neutron Source for BNCT Versus Beam Energy
Characterisation of an Accelerator-Based Neutron Source for BNCT Versus Beam Energy
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BNCT 加速器中子源与束流能量的表征
DOI：
10.1016/s0168-9002(01)01402-4
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
R. Tinti
中科院分区：
文献类型：
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作者：
S. Agosteo;G. Curzio;F. d'Errico;R. Nath;R. Tinti
10 B中的中子俘获产生高能α粒子，其在组织中具有高线性能量转移。与光子相比，这导致更高的细胞杀伤和更高的相对生物学有效性。使用适当设计的硼化合物，其优先定位在癌细胞而不是健康组织中，硼中子捕获疗法（BNCT）具有在对正常组织的最小毒性内提供更高的肿瘤治愈率的潜力。这种临床方法需要热中子源，通常是核反应堆，其注量率足以在合理的治疗时间（分钟）内递送杀肿瘤剂量。热中子不会深入组织，因此BNCT仅限于浅表或其他可触及的病变。在这项工作中，我们研究了基于加速器的热中子源的皮肤黑色素瘤的BNCT的可行性。该源的设计是通过MCNP蒙特卡罗模拟热化的快中子束，所产生的7 MeV的氘核撞击厚靶铍。在意大利莱尼亚罗国立大学的货车德格拉夫加速器上的一个实验装置中，对几种氘能（3.0-6.5MeV）的中子场进行了表征。用活化技术测量了热中子和超热中子注量，用过热液滴探测器（SDD）测定了快中子谱。这些中子能谱和剂量学研究表明，在目前的设计中，快中子剂量高得不可接受。目前的设计，以克服这个问题的修改。
Neutron capture in10B produces energetic alpha particles that have a high linear energy transfer in tissue. This results in higher cell killing and a higher relative biological effectiveness compared to photons. Using suitably designed boron compounds which preferentially localize in cancerous cells instead of healthy tissues, boron neutron capture therapy (BNCT) has the potential of providing a higher tumor cure rate within minimal toxicity to normal tissues. This clinical approach requires a thermal neutron source, generally a nuclear reactor, with a fluence rate sufficient to deliver tumorcidal doses within a reasonable treatment time (minutes). Thermal neutrons do not penetrate deeply in tissue, therefore BNCT is limited to lesions which are either superficial or otherwise accessible. In this work, we investigate the feasibility of an accelerator-based thermal neutron source for the BNCT of skin melanomas. The source was designed via MCNP Monte Carlo simulations of the thermalization of a fast neutron beam, generated by 7MeV deuterons impinging on a thick target of beryllium. The neutron field was characterized at several deuteron energies (3.0–6.5MeV) in an experimental structure installed at the Van De Graaff accelerator of the Laboratori Nazionali di Legnaro, in Italy. Thermal and epithermal neutron fluences were measured with activation techniques and fast neutron spectra were determined with superheated drop detectors (SDD). These neutron spectrometry and dosimetry studies indicated that the fast neutron dose is unacceptably high in the current design. Modifications to the current design to overcome this problem are presented.