Suzuki Minoru, Sakurai Yoshinori, Masunaga Shinichiro, Kinashi Yuko, Nagata Kenji, Ono Koji
Radiation Oncology Research Laboratory, Research Reactor Institute, Kyoto University, Osaka, Japan.
Int J Radiat Oncol Biol Phys. 2004 Mar 1;58(3):892-6. doi: 10.1016/j.ijrobp.2003.09.084.
We performed a computational study to investigate the feasibility of borocaptate sodium (BSH)/lipiodol-boron neutron capture therapy (BSH/lipiodol-BNCT) for multiple liver tumors using Simulation Environment for Radiotherapy Applications (SERA), a currently available BNCT treatment planning system.
Three treatment plans for BSH/lipiodol-BNCT using two or three epithermal neutron beams in one fraction were generated for 4 patients with multiple liver tumors using the SERA system. The (10)B concentrations in the tumor and the liver assumed in the study were 197.3 and 15.3 ppm, respectively; and were obtained from experimental studies in animals. The therapeutic gain factors for the liver tumors, defined as the minimum dose to the tumor/maximum dose to the liver, and the inhomogeneity index of the thermal neutron fluence for the whole of the liver, defined as the maximum neutron fluence - minimum neutron fluence/mean neutron fluence, were evaluated in each plan.
Three epithermal neutron beams incident on the anterior, posterior, and right side of the patient can deliver the most homogeneous distribution of thermal neutron fluence to the whole of the liver and provide the greatest therapeutic gain factors for tumors in the right lobe and approximately equal therapeutic gain factors for tumors in the left lobe, compared with the two opposed (anterior-posterior) and two orthogonal (anterior-right) beams.
From a dosimetric viewpoint, the BSH/lipiodol-BNCT treatment plan using three epithermal neutron beams is the most suitable for the treatment of multiple liver tumors.
我们使用现有的硼中子俘获疗法（BNCT）治疗计划系统——放射治疗应用模拟环境（SERA），进行了一项计算研究，以探讨硼酸钠（BSH）/碘油 - 硼中子俘获疗法（BSH/碘油 - BNCT）治疗多发性肝肿瘤的可行性。
使用SERA系统为4例多发性肝肿瘤患者生成了三个BSH/碘油 - BNCT治疗计划，这些计划采用一次分割使用两束或三束超热中子束。研究中假设肿瘤和肝脏中的硼 - 10浓度分别为197.3 ppm和15.3 ppm；这些数据来自动物实验研究。在每个计划中评估了肝肿瘤的治疗增益因子，定义为肿瘤的最小剂量/肝脏的最大剂量，以及整个肝脏热中子注量的不均匀性指数，定义为最大中子注量 - 最小中子注量/平均中子注量。
与两束相对（前后）和两束正交（前右）的中子束相比，入射到患者前侧、后侧和右侧的三束超热中子束可以为整个肝脏提供最均匀的热中子注量分布，为右叶肿瘤提供最大的治疗增益因子，为左叶肿瘤提供大致相等的治疗增益因子。
从剂量学角度来看，使用三束超热中子束的BSH/碘油 - BNCT治疗计划最适合治疗多发性肝肿瘤。
