An Epithermal Neutron Source for Cancer Therapy

描述（由申请人提供）：我们建议开发一种基于硼中子俘获疗法（BNCT）的商业中子源，用于治疗脑癌和肝癌。含硼化合物被注射到病人的血液中，并在恶性肿瘤中积累。当用中子照射时，硼原子优先捕获中子并衰变，释放出杀死肿瘤但不会明显损害其他组织的短程辐射。BNCT主要在大型昂贵的核反应堆上进行了测试，这些核反应堆不能用于临床环境。所提出的这种来源相对便宜，体积小，可以在医院使用，而且操作安全。此外，它将被设计成产生理想的超热中子谱（与反应堆不同），并有望在短处理时间内产生足够的中子通量。提出的源包括一个使用D-T反应的rf等离子体快中子源和一个优化的紧凑慢化剂来减慢和准直中子。这些组件以一种新颖的方式组合在一起，为BNCT产生高通量、最佳的超热中子谱。氚的储存、补充和回收将由一个独立的真空系统来实现，以尽量减少辐射和爆炸危险。我们的设计是新颖的，因为它集成了等离子体中子源，使用优化的快中子靶和新的慢化剂材料和几何形状，以提高效率和紧凑性。初步分析表明，优化目标阳极的几何形状可以降低发电机所需的功率，并与适当设计的慢化剂相结合。蒙特卡罗n粒子（MCNP）分析将得到改进，以确定D-T发生器的几何形状，并采用慢慢剂配置，以产生最佳中子能量和最小功耗的中子束。为了便于水冷却，目标阳极上的离子束功率密度将小于每平方厘米150瓦。我们将使用放射治疗应用模拟环境（SERA）治疗程序创建一个用于剂量计算的源模型。为了比较，我们将使用MCNP程序在患者模型中计算剂量。快中子发生器将使用该研究所开发的计算机代码进行设计。先前的快中子源已经被制造和测试，证明了这些代码的有效性和研究所的技术技能。

DESCRIPTION (provided by applicant): We propose to develop a commercial neutron source for the treatment of brain and liver cancer based on boron neutron capture therapy (BNCT). Boron-containing compounds are injected into a patient's bloodstream and accumulate in a malignant tumor. When irradiated with neutrons, the boron atoms preferentially capture neutrons and decay, releasing short-range radiation that kills the tumor but does not appreciably damage other tissues. BNCT has been tested using primarily nuclear reactors that are large and expensive and cannot be used in a clinical setting. The proposed source is relatively inexpensive, compact enough to be used in hospitals and promises safe operation. In addition, it will be designed to produce an ideal epithermal neutron spectrum (unlike reactors) and is expected to produce enough neutron flux for short treatment times. The proposed source consists of an rf-plasma fast-neutron source using the D-T reaction and an optimized, compact moderator to slow and collimate the neutrons. These components are brought together in a novel fashion to produce a high-flux, optimum epithermal neutron spectrum for BNCT. Tritium storage, replenishing and recycling will be achieved by a self-contained vacuum system to minimize radiation and explosion hazards. Our design is novel in that it integrates the plasma neutron source using an optimized fast-neutron target with new moderator materials and geometries for greater efficiency and compactness. Preliminary analysis shows that optimizing the target-anode's geometry can decrease the required power to the generator when integrated with a properly designed moderator. This Monte-Carlo N-particle (MCNP) analysis will be improved to determine the D-T generator's geometry with a moderator configuration that will produce a neutron beam of optimum neutron energy and minimize power consumption. To facilitate water cooling, the ion beam power density on the target anode will be less than 150 Watts per square cm. We will create a source model for dose calculations using the Simulation Environment for Radiotherapy Application (SERA) treatment program. For comparison, we will calculate the dose in a patient model with the MCNP program. The fast-neutron generator will be designed using computer codes developed at the research institute. Prior fast neutron sources have been fabricated and tested demonstrating the efficacy of these codes and the research institute's technological skill.