Wheeler F J, Nigg D W, Capala J, Watkins P R, Vroegindeweij C, Auterinen I, Seppälä T, Bleuel D
Center for Advanced Radiation Therapies, Idaho National Engineering and Environmental Laboratory, Idaho Falls 83415-3890, USA.
Med Phys. 1999 Jul;26(7):1237-44. doi: 10.1118/1.598618.
The potential efficacy of boron neutron capture therapy (BNCT) for malignant glioma is a significant function of epithermal-neutron beam biophysical characteristics as well as boron compound biodistribution characteristics. Monte Carlo analyses were performed to evaluate the relative significance of these factors on theoretical tumor control using a standard model. The existing, well-characterized epithermal-neutron sources at the Brookhaven Medical Research Reactor (BMRR), the Petten High Flux Reactor (HFR), and the Finnish Research Reactor (FiR-1) were compared. Results for a realistic accelerator design by the E. O. Lawrence Berkeley National Laboratory (LBL) are also compared. Also the characteristics of the compound p-Boronophenylaline Fructose (BPA-F) and a hypothetical next-generation compound were used in a comparison of the BMRR and a hypothetical improved reactor. All components of dose induced by an external epithermal-neutron beam fall off quite rapidly with depth in tissue. Delivery of dose to greater depths is limited by the healthy-tissue tolerance and a reduction in the hydrogen-recoil and incident gamma dose allow for longer irradiation and greater dose at a depth. Dose at depth can also be increased with a beam that has higher neutron energy (without too high a recoil dose) and a more forward peaked angular distribution. Of the existing facilities, the FiR-1 beam has the better quality (lower hydrogen-recoil and incident gamma dose) and a penetrating neutron spectrum and was found to deliver a higher value of Tumor Control Probability (TCP) than other existing beams at shallow depth. The greater forwardness and penetration of the HFR the FiR-1 at greater depths. The hypothetical reactor and accelerator beams outperform at both shallow and greater depths. In all cases, the hypothetical compound provides a significant improvement in efficacy but it is shown that the full benefit of improved compound is not realized until the neutron beam is fully optimized.
硼中子俘获疗法（BNCT）对恶性胶质瘤的潜在疗效是超热中子束生物物理特性以及硼化合物生物分布特性的重要函数。使用标准模型进行了蒙特卡罗分析，以评估这些因素对理论肿瘤控制的相对重要性。比较了布鲁克海文医学研究反应堆（BMRR）、佩滕高通量反应堆（HFR）和芬兰研究反应堆（FiR-1）现有的、特征明确的超热中子源。还比较了美国劳伦斯伯克利国家实验室（LBL）实际加速器设计的结果。此外，在比较BMRR和假设的改进反应堆时，使用了化合物对硼苯丙氨酸果糖（BPA-F）和一种假设的下一代化合物的特性。外部超热中子束诱导的剂量的所有成分在组织中随深度迅速下降。向更深部位输送剂量受到健康组织耐受性的限制，氢反冲和入射伽马剂量的降低允许更长时间的照射和在更深部位有更大的剂量。深度剂量也可以通过具有更高中子能量（反冲剂量不过高）和更向前峰值角分布的束流来增加。在现有设施中，FiR-1束流质量更好（氢反冲和入射伽马剂量更低）且具有穿透性中子能谱，发现在浅深度时比其他现有束流能提供更高的肿瘤控制概率（TCP）值。HFR在更深部位比FiR-1具有更大的向前性和穿透性。假设的反应堆和加速器束流在浅深度和更深部位都表现更优。在所有情况下，假设的化合物在疗效上有显著改善，但结果表明，在中子束完全优化之前，改进化合物的全部益处无法实现。
