Pharmaco-thermodynamics of deuterium-induced oedema in living rat brain via 1H2O MRI: implications for boron neutron capture therapy of malignant brain tumours.
Pharmaco-thermodynamics of deuterium-induced oedema in living rat brain via 1H2O MRI: implications for boron neutron capture therapy of malignant brain tumours.
复制标题
通过 1H2O MRI 观察活体大鼠脑中氘诱导水肿的药热动力学：对恶性脑肿瘤的硼中子捕获治疗的影响。
DOI：
10.1088/0031-9155/50/9/014
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
SpringerJr,CharlesS
中科院分区：
文献类型：
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作者：
Medina,DanielC;Li,Xin;SpringerJr,CharlesS
除了在代谢和生理研究中作为示踪剂的常见用途外，氘还具有抗肿瘤活性，并提供对γ辐射的保护。最近对氚的兴趣源于寻找能够改善中子透过率的替代方案，同时在恶性脑瘤的硼中子俘获治疗中减少健康组织的辐射剂量沉积。尽管有这种潜在的临床应用，但氚会导致脑水肿，这对中子俘获治疗是不利的。在这项研究中，5只成年雄性大鼠用氚水进行滴定，同时通过水质子磁共振成像监测脑水肿。这份报告得出的结论是，氢以及氢引起的脑水肿，具有均匀的脑生物分布。在16%的稳态血液中，当饮用水中的氚同位素含量为25%时，观察到大鼠脑内平均水肿量的变化为9±2%(p值<；0.001)，这可能是饮用高氚水的哺乳动物出现神经和行为异常的原因。此外，本报告还利用简单的线性输运计算，估计了水肿胀对热中子增强和有效剂量减少因子的影响。虽然体液氚增加了热中子通量的透过率，减少了剂量沉积，但水肿胀却有相反的作用，因为它增加了感兴趣的体积，如脑体积。在水体积增加9%的情况下，热中子增强和有效剂量减少因子可以减少多达10%的∼。
In addition to its common usage as a tracer in metabolic and physiological studies, deuterium possesses anti-tumoural activity and confers protection against γ-irradiation. A more recent interest in deuterium emanates from the search for alternatives capable of improving neutron penetrance whilst reducing healthy tissue radiation dose deposition in boron neutron capture therapy of malignant brain tumours. Despite this potential clinical application, deuterium induces brain oedema, which is detrimental to neutron capture therapy. In this study, five adult male rats were titrated with deuterated drinking water while brain oedema was monitored via water proton magnetic resonance imaging. This report concludes that deuterium, as well as deuterium-induced brain oedema, possesses a uniform brain bio-distribution. At a steady-state blood fluid deuteration value of 16%, when the deuterium isotope fraction in drinking water was 25%, a mean oedematous volume change of 9±2%(p-value< 0.001) was observed in the rat brain—this may account for neurological and behavioural abnormalities found in mammals drinking highly deuterated water. In addition to characterizing the pharmaco-thermodynamics of deuterium-induced oedema, this report also estimates the impact of oedema on thermal neutron enhancement and effective dose reduction factors using simple linear transport calculations. While body fluid deuteration enhances thermal neutron flux penetrance and reduces dose deposition, oedema has the opposite effect because it increases the volume of interest, eg, the brain volume. Thermal neutron enhancement and effective dose reduction factors could be reduced by as much as∼ 10% in the presence of a 9% water volume increase (oedema).