Imahori Y, Ueda S, Ohmori Y, Sakae K, Kusuki T, Kobayashi T, Takagaki M, Ono K, Ido T, Fujii R
Department of Neurosurgey, Kyoto Prefectural University of Medicine, Japan.
Clin Cancer Res. 1998 Aug;4(8):1833-41.
Based on pharmacokinetic findings of fluorine-18-labeled L-fluoroboronophenylalanine by positron emission tomography (PET), methods for estimating tumor 10B concentration were devised. In clinical practice of boron neutron capture therapy (BNCT) for high-grade gliomas, a large amount of L-boronophenylalanine (L-10B-BPA)-fructose solution is used. Under these conditions, a slow i.v. infusion of L-10B-BPA-fructose solution should be performed for BNCT; therefore, the changes over time in 10B concentration in the target tissue were estimated by convoluting the actual time course of changes in plasma 10B concentration with a PET-based weight function including the proper rate constants [K1 (ml/g/min), k2 (min(-1)), k3 (min(-1)), and k4 (min(-1))]. With this method, the estimated values of 10B concentration in gliomas were very close to the 10B levels in surgical specimens. This demonstrated the similarity in pharmacokinetics between fluorine-18-labeled L-fluoroboronophenylalanine and L-10B-BPA. This method, using the appropriate rate constant, permits the determination of tumor 10B concentration and is widely suitable for clinical BNCT, because the averaged PET data are enough to use in future patients without individual PET study.
基于正电子发射断层扫描（PET）对氟-18标记的L-氟硼苯丙氨酸的药代动力学研究结果，设计了估算肿瘤硼-10浓度的方法。在高级别胶质瘤的硼中子俘获疗法（BNCT）临床实践中，会使用大量的L-硼苯丙氨酸（L-10B-BPA）-果糖溶液。在这些条件下，进行BNCT时应缓慢静脉输注L-10B-BPA-果糖溶液；因此，通过将血浆硼-10浓度的实际时间变化过程与包含适当速率常数[K1（ml/g/min）、k2（min⁻¹）、k3（min⁻¹）和k4（min⁻¹）]的基于PET的权重函数进行卷积，来估算靶组织中硼-10浓度随时间的变化。用这种方法，胶质瘤中硼-10浓度的估算值与手术标本中的硼-10水平非常接近。这证明了氟-18标记的L-氟硼苯丙氨酸和L-10B-BPA在药代动力学上的相似性。这种使用适当速率常数的方法能够测定肿瘤硼-10浓度，并且广泛适用于临床BNCT，因为平均PET数据足以用于未来患者，无需进行个体PET研究。
