Depth-dose evaluation for gadolinium neutron capture therapy

钆中子俘获疗法的深度剂量评估

• 批准号: 03680197
• 负责人: MATSUMOTO Tetsuo
• 金额: $ 1.02万
• 依托单位: Musashi Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03680197/
• 关键词: Gadolinium; Neutron capture; Neutron transport code; Dose distribution; capture gamma-rays; Internal conversion electrons; Phantom; 中性子; ファニトム; 熱外中性子; 2次元中性子輸送コ-ド

The isotope gadolinium (^<157>Gd) has been suggested as an alternative neutron capture (NCT) agent to ^<10>B. Possible advantages of Gd-NCT are as follows : (i) thermal neutron cross sections (245,000 barn) for ^<157>Gd is 66 times larger than that of ^<10>B. (ii) gadolinium neutron capture reactions produce prompt gamma-rays with relatively low energy accompanying by emission of low energy conversion and Auger electrons. (iii) gadolinium is used as a contrast medium for magnetic resonance imaging (MRI) and may lead to an effective Gd-NCT compound.In this study the depth-dose distributions were evaluated by phantom experiments and calculations for possible application of Gd-NCT. The experiments were carried out at the irradiation port in the experimental beam hole (7R) of JRR3M. The distributions of thermal neutron flux and gamma-ray dose rate in a tumor-simulated phantom were measured by gold foil activation, TLDs and film methods. A two-dimensional neutron-coupled gamma-ray transport code (DOT3.5) was also employed for the calculations of neutron and capture gamma-ray fluence rates.The calculations and experiments showed that (i) a significant dose can be delivered to a tumor when Gd is accumulated in the tumor. (ii) the dose distribution was a function of storongly interrelated parameters such as gadolinium concentrations, tumor site and collimator aperture (neutron beam size). (iii) the Gd-NCT by thermal neutrons appears to be strong potential for treatment of superficial tumors.

同位素钆（^<157>Gd）已被建议作为^ B的替代中子捕获（NCT）剂<10>。Gd-NCT可能的优点如下：（i）^ Gd的热中子截面（245，000 barn）<157>比^ B大66倍<10>。(ii)钆中子俘获反应产生具有相对低能量的瞬发γ射线，伴随着低能量转换和俄歇电子的发射。(iii)本文通过体模实验和计算，对Gd-NCT的深度-剂量分布进行了研究，为Gd-NCT的应用提供了理论依据。实验在JRR 3 M实验束孔（7 R）中的照射口处进行。用金箔活化法、热释光法和胶片法测量了模拟肿瘤体模中热中子注量率和γ射线剂量率的分布。采用二维中子耦合γ射线输运程序（DOT 3.5）计算了中子和俘获γ射线注量率，计算和实验表明：（i）当肿瘤中积累Gd时，可以向肿瘤输送显着的剂量。(ii)剂量分布是强烈相关的参数的函数，例如钆浓度、肿瘤位置和准直器孔径（中子束尺寸）。(iii)利用热中子的Gd-NCT似乎具有治疗浅表肿瘤的强大潜力。

项目成果

Tetsuo Matsumoto: "Evaluation of depth-dose distributions for gadolinium neutron capture therapy." Proceedings of the 5th International Symposium on Neutron Capture Therapy for Cancer. (1993)

Tetsuo Matsumoto：“钆中子俘获疗法深度剂量分布的评估。”

Tetsuo Matsumoto: "Transport calculations of depth-dose distributions for gadolinium neutron capture therapy." Phys. Med. Biol.37. 155-162 (1992)

Tetsuo Matsumoto：“钆中子俘获疗法深度剂量分布的传输计算。”

Tetsuo Matsumoto et al.: "Phantom experiment of depth-dose distributions for gadolinium neutron capture therapy." Proceedings of the 5th International Symposium Advanced Neutron Energy Research.(1993)

Tetsuo Matsumoto 等人：“钆中子俘获疗法深度剂量分布的幻影实验。”