纳米铁核素靶向内照射治疗肿瘤的剂量学研究

【作者】 刘建庭；

【导师】 熊平；

【作者基本信息】 中南大学 ， 生物信息物理学， 2007， 硕士

【摘要】 目的：为定位治疗肿瘤提供一种新型的内照射放射源——纳米铁核素，着重考察纳米铁核素在体内的剂量学行为，为纳米铁核素靶向内照射治疗肿瘤的临床应用提供理论参考。研究方法：(1)自行制备试验用纳米铁核素，对其进行顺磁性和放射性活度等物理性能检测，确定最佳定位靶向系统；(2)应用LUDEP内照射辐射吸收剂量计算软件，估算常规无靶向内照射治疗肝癌时，靶器官肝脏及全身各器官的吸收剂量；(3)在三维旋转磁场定位仪作用下的靶向系统中，应用MIRD方法计算纳米铁核素对靶器官肝脏和全身其它器官的剂量贡献。结论：(1)纳米铁核素的物理半衰期为45.1天，最大能量为1.575MeV，平均能量为0.371 MeV，适合作为临床用放射性核素；(2)放射治疗时微小量的纳米铁核素可能逃离三维磁场定位仪工作区而顺着血流方向流向全身，但由于铁是人体必需的元素，少量的纳米铁核素沉积到人体其它器官不会造成机体中毒；(3)治疗结束撤去外加磁场后，纳米铁核素衰变后剩余的微量流向脾等全身器官，微小量的辐射衰变对沉积器官不会造成辐射损伤；(4)对比常规内照射计算结果和靶向内照射计算结果我们可以看出，给予相同的初始活度，本研究给予靶器官的吸收剂量比常规内照射大一个数量级，身体其它正常组织器官可能受到的辐射损伤明显减小，同时避免了放疗时组织的剂量耐受效应。更多还原

【Abstract】 PURPOSE: The purpose of this study was to provide a new nuclide type——nanometer-iron nuclide for targeted internal radionuclide therapy,and especially to investigate posology of nanometer-iron nuclide inhuman body. This paper served as a guideline for nanometer-iron nuclidebeing applied to targeted internal radionuclide therapy. METHED:(1)Prepared nanometer-iron nuclide by experiment and identified it’sphysics characters, such as paramagnetism, radioactity, then established aoptimum positioning targeted system for nanometer-iron nuclide;(2)Estimated the absorbed dose of the target organ liver and the otherorgans of the whole body in normal no-targeted internal radionuclidetherapy of liver cancer by a software LUDEP which used for calculatingthe dosage of internal radionuclide therapy; (3)Under the influence of thethree-dimensional magnetic locator, calculated the contribution ofnanometer-iron nuclide for target organ liver and the other organs of thewhole body by MIRD method. CONCLUSION: (1) The physicalcharacters of nanometer-iron nuclide up to the standard of clinicradionuclide, so nanometer-iron nuclide fit for a clinic radionuclide. Andmoreover derivatives generated by radioactive decay of thenanometer-iron nuclide was not radioactive and would not pollute thehuman body. (2)Trace nanometer-iron nuclide may escape from themagnetic field of the three-dimensional magnetic locator and thendiffused to the whole body along the direction of the bloodstream. Butiron is a necessary element for human body, so trace nanometer-ironnuclide which deposited in other organs would not cause poisoning.(3) When the outside magnetic field was removed, the rest of thenanometer-iron nuclide of radioactive decay diffused to the otherorgans, such as spleen. Trace sediment of the radioactive decay would notcause radioactive damage. (4) Compared the result of normal internalradionuclide therapy with that of targeted internal radionuclide therapy,we can see that the absorbed dose of target organ in targeted internalradionuclide therapy is one order greater in magnitude than that of innormal internal radionuclide therapy. Radioactive damage which other normal organ maybe suffered decreased greatly. Meanwhile, the dosetolerance effect of tissues maybe avoided in radiotherapy.更多还原