放射性核素及其标记物的临床应用价值

随着人们对放射性核素认识的不断加深,放射性核素及其标记物已广泛应用于生物医学的基础研究和临床实践,为医学科学的发展和人类的健康事业做出了巨大的贡献。以放射性核素及其标记化合物为基础,将核科学技术应用于疾病的研究、诊断和治疗,形成了现代医学的一个重要分支——核医学。放射性核素及其标记物在肿瘤、心血管疾病和神经系统疾病的诊断、治疗决策、疗效评价及预后评估中起到重要的作用,其在疾病治疗、体外分析和生物医学研究中的重要作用也得到了肯定。     

放射性核素治疗骨转移癌的研究进展

概述了目前放射性核素治疗骨转移癌的现状及存在的问题。对一些放射性核素及其标记物在治疗骨转移癌方面的作用机理、特性、使用方法、临床评价及优点进行了评述，提出了今后如何在基础与临床应用方面进一步研究。     

放射性核素迁移研究的现状

综述了放射性核素迁移研究的历史发展过程和现状，着重叙述了放射性核索迁移研究中，实验室模拟研究、天然类比研究、计算机模拟研究和示踪研究的方法及其进展。     

放射性核素在矿物表面的吸附微观结构分析进展

放射性核素在矿物表面的吸附行为是影响其在环境中的浓度、迁移、转化及毒性的重要过程。本文简要介绍了放射性核素在吸附剂表面的吸附、沉淀、氧化还原反应的作用机理，针对放射性核素在矿物表面的微观吸附形态的研究中所使用的一些先进的实验分析方法，重点介绍了同步辐射X射线吸收精细结构（XAFS）技术、荧光分析以及理论计算等技术，并展望了放射性核素在矿物表面微观反应机制的研究趋势。     

环境放射化学研究中几个问题的讨论

本文从辐射环境保护和公众辐射防护的角度，讨论了放射性核素在环境中的迁移行为，放射性核素与环境介质的相互作用和放射性核素在环境中的形态等涉及到环境放射化学研究方向的问题，并讨论了它们之间相互依存的关系。     

茶汤中^3H,^14C等核素的探测

本文介绍了七大类４８个样品茶及其茶汤中＾３Ｈ、＾１４Ｃ、＾２３８Ｕ等放射性核素和总α，β辐射水平，及对人体所致有效剂量当量。     

125Ⅰ的生产现状与前景展望

放射性核素1255Ⅰ在生物医学、放射免疫体外诊断和近距离植入治疗肿瘤等方面得到广泛应用.本文简要介绍了125Ⅰ的生产工艺、国内生产现状及国内市场需求,并对国内反应堆辐照生产125Ⅰ的前景进行了展望.     

放射性治疗药物的发展现状与展望

放射性治疗药物是将放射性核素与载体结合，利用放射性核素适宜的射线能量和在组织中的射程，选择性集中照射病变组织，同时避免正常组织受损并获得预期治疗效果，现主要用于肿瘤治疗或缓解肿瘤相关症状等。放射性药物广泛应用于肿瘤诊疗、心肌显像、神经退行性疾病早期发现和炎症组织显像诊断等。近年来，随着靶向性配体的快速发展，以及新型医用核素广泛应用，放射性治疗药物受到了越来越多的关注，目前¹⁵³Sm、⁸⁹Sr、²²³Ra、⁹⁰Y、¹³¹I和¹⁷⁷Lu等核素常用于治疗癌症骨转移、肝癌、甲状腺癌等，且治疗上显示出较大潜力，相关放射性治疗药物的研究也迅速增加。本文就已上市和研究阶段放射性治疗药物的临床应用和发展现状进行介绍，以期为我国放射性治疗药物的研发提供参考。     

我国禁核试核素核查技术发展与展望

自1996年签署《全面禁止核试验条约》(CTBT)以来，我国在禁核试核查监测技术方面取得重要进展。作为唯一能够提供核爆炸定性证据的技术手段，核素核查技术研究经过二十年的发展，建立了满足台站和现场核素监测要求的取样与测量技术手段和禁核试北京放射性核素实验室，拥有了能够有效履行条约义务、保障我国国土和环境安全的技术能力，在周边各类核事件、核事故等应急监测中发挥了重要作用。本文简要回顾我国禁核试核素核查技术的发展历程、重要成果和技术现状，分析后续核素核查和监测技术发展的主要方向。     

放射性核素有机迁移形式与性能评价

人们在以往的性能评价中大多注意地下水中放射性核素的无机迁移形式,而对其有机迁移形式则关注不够,这无疑会影响处置库系统性能评价的置信度。本文重点讨论了天然有机质在地下水中的分布及其对高放废物处置库系统性能评价的可能影响。最近研究结果表明:黏土岩一般为不透水层,DOC、HA和FA在黏土岩孔隙水中的质量浓度要远比在花岗岩地下水中的高。因此,对黏土岩中的预选场址要十分关注放射性核素有机迁移形式及其对性能评价的影响。花岗岩地下水中虽然DOC甚低,但是否可完全不考虑放射性核素有机迁移形式对性能评价的影响,现在未作定论,尚在进一步研究之中。     

Peptides radiolabelled with Re-186/188 and Tc-99m as potential diagnostic and therapeutic agents

Small peptide-based compounds have attracted an enormous interest as carrier molecules to selectively deliver radionuclides to target tissues, sparing critical normal organs. When looking for "matched pairs" of radionuclides,suitable for radiolabeling of peptides for diagnosis and therapy, technetium and rhenium represent an almost ideal constellation. The important role of technetium-99m and Re-186/188 is based on the decay characteristics, suitable for tumor diagnosis and therapy. Tc-99m and Re-188 are readily available by either a 99Mo/99mTc or the 188W/188Re radionuclide generator system. Furthermore, technetium and rhenium are chemically related and share structural as well as reactive similarities, which prompt an attractive "matched-pair" situation. This article shows an overview of 99mTc-and 186/188Re-radiolabeled peptides that have been tested for their potential use as imaging and therapeutic agents in oncological diseases.     

Development of calculation methodology for estimation of radionuclide composition in wastes generated at Fukushima Daiichi nuclear power station

ABSTRACT

A calculation methodology for estimating the radionuclide composition in the wastes generated at the Fukushima Daiichi nuclear power station has been developed by constructing a skeleton overview of the distribution of radionuclides considering the material balance in the system and calculation flowcharts of the transportation of radionuclides into the wastes. The wastes have a distinctive feature that their level of contamination includes considerable uncertainties because the process behind the contamination with the radionuclides released from the damaged fuel during and after the accident is not yet fully understood. Here, the developed method can explicitly specify the intrinsic uncertainties as a band to be included in the estimated radionuclide composition in the wastes and can quantitatively describe the uncertainties by calibration using analytically measured data on actual waste samples collected at the site. Further studies to improve the quality of the calculation method, the introduction of a stochastic approach to describe uncertainties, and acquiring a quantitative understanding of the spatial distribution of radionuclides inside the reactor building are suggested as important steps toward reasonable and sustainable waste management as an integral part of the decommissioning of the Fukushima Daiichi nuclear power station.     

正电子核素标记奥曲肽类似物的研究进展

奥曲肽是一种人工合成的含有8个氨基酸的生长抑素类似物,与生长抑素受体(SSTR)能够高特异性地结合。肿瘤细胞组织上常有一些生长抑素受体的过度表达,因此,应用正电子核素标记的奥曲肽及其类似物作为肿瘤示踪剂,对生长抑素受体阳性肿瘤进行诊断与治疗具有潜在的重要的临床意义。本文就正电子核素标记的奥曲肽类似物的研究现状进行综述。     

161Tb标记放射性药物的研究进展

放射性镧系元素¹⁶¹Tb与广泛使用的放射性核素¹⁷⁷Lu性质相似,且疗效更好,有望成为新型的放射性治疗核素。目前,应用¹⁶¹Tb的研究主要集中于¹⁶¹Tb标记生物分子的体内行为,以及与¹⁷⁷Lu相比,其对恶性肿瘤的疗效。初步的治疗研究表明,在相同的活度下,¹⁶¹Tb在肿瘤治疗方面比¹⁷⁷Lu更有效。本研究对¹⁶¹Tb的特性、制备及其标记放射性药物的研究进展进行综述,为治疗用放射性核素的开发及临床应用提供参考。     

Computer Code System DSOCEAN for Assessing the Collective Dose of Japanese due to Radionuclides Released to the Ocean from a Reprocessing Plant

A computer code system DSOCEAN has been developed for assessing the collective dose of Japanese due to radionuclides released to the ocean from a spent nuclear fuel reprocessing plant. This computer code system uses a box model which represents the transfer of radionuclides between boxes of seawater into which the ocean around Japan is divided. The code system consists of a series of three interlinked main computer codes, which estimates the exchange rates of radionuclides between the boxes, the radionuclide concentrations in each box, and the collective dose from various exposure pathways, respectively.

By using DSOCEAN, two calculations were carried out to estimate the collective dose from a liquid effluent. One is associated with a routine release of radionuclides from a hypothetical reprocessing plant. The other is an application of the code system to disposal of liquid radioactive waste to the surface water of the ocean. The calculated results identified important radionuclides and exposure pathways.     

Peptides radiolabeled with Re-186/188 and Tc-99m as potential diagnostic and therapeutic agents

Small peptide-based compounds have attracted an enormous interest as carrier molecules to selectively deliver radionuclides to target tissues, sparing critical normal organs. When looking for ＂matched pairs＂ of radionuclides, suitable for radiolabeling of peptides for diagnosis and therapy, technetium and rhenium represent an almost ideal constellation. The important role of technetium-99m and Re-186/188 is based on the decay characteristics, suitable for tumor diagnosis and therapy. Tc-99m and Re-188 are readily available by either a ^99Mo/^99mTc or the ^188w/^188Re radionuclide generator system Furthermore, technetium and rhenium are chemically related and share structural as well as reactive similarities, which prompt an attractive ＂matched-pair＂ situation. This article shows an overview of ^99mTc- and ^186/188Re-radiolabeled peptides that have been tested for their potential use as imaging and therapeutic agents in oncological diseases.     

Recent advances in medical radionuclide production and future perspective of compact medical cyclotrons

In recent years, many radiopharmaceuticals bearing different kind of radionuclides have been largely used in diagnostic and therapeutic studies, especially of cancer. The basic principle of radiodiagnosis and raditherapy is ensuring as low as radiation dose absorption by patients. Sometimes, the radionuclides having very short half-lives, and very interesting decay characteristics are required for this purpose. The use of short-lived radionuclides necessitates their productions just at the application sites. This necessity has provoked the development of compact particle accelerators. Nowadays, the radionuclide applications in diagnostic and therapeutic nuclear medicine are continuously escalation, and future perspective of these applications will strongly be depended on two important factors as being 1) increasing the variety of cyclotron-produced radionuclides, 2) design of new radiopharmaceuticals having different and specific metabolic pathways in normal and cancer tissues. For improvement of the first factor, new nuclear reactions should eventually be examined using new target materials. In this context, the targeting chemistry will be an essential role in this field. As the second factor, improvement of new radiopharmaceuticals will strongly be dependent on the biofunctional researches of new chemical agents and development of their radiolabeling techniques. The radionuclide production has evidently become more and more easy by using the compact medical cyclotrons. For this reason, the application of different radionuclides will be able to have an important role in the future either for scientific and technical applications or medical diagnostic and therapeutic studies. As a consequence of this progress, the basic nuclear scientists, especially nuclear and radiopharmaceutical chemists will be seeking professionals in the next new century.     

基于武器级铀的核弹头内部炸药的放射性核素分析

在军备控制核查技术领域,核弹头拆卸认证是重要的研究对象。本文分析了基于武器级铀的核弹头(即铀弹头)内部炸药的放射性核素的产生、种类和数目,旨在研究炸药中放射性核素的被动式探测法是否可用于铀弹头中拆卸出的炸药的来源鉴别。结果表明,在铀弹头内部炸药中,短寿命放射性核素(~(16)N、~(15)O、~(13)N和~(11)C)的数目太少(少于1个),因此在铀弹头拆卸后,无法通过探测这些短寿命放射性核素来实现炸药的来源鉴别。而对于存放时间超过30a、内部结构遵从模型1(由Steve Fetter提出)的铀弹头,拆卸后炸药中的长寿命放射性核素(~(14)C)可被检测出来,进而能为炸药的来源鉴别提供重要依据。     

整合素素αⅤβ3受体显像剂18F标记RGD肽的研究进展

血管新生是肿瘤生长、转移过程中不可缺少的生物过程。整合素α_Ⅴβ₃受体在新生血管内皮细胞和多种肿瘤细胞表面高表达,在肿瘤血管新生中起着关键作用,目前已成为肿瘤诊断与治疗的一个重要靶点。精氨酸-甘氨酸-天冬氨酸（Arg-Gly-Asp, RGD）肽可特异性地与整合素α_Ⅴβ₃受体结合,¹⁸F标记的RGD肽类化合物PET显像可无创、动态地定量监测整合素α_Ⅴβ₃受体表达,在肿瘤早期诊断、疗效监测及抗血管新生评价上发挥着重要作用。本文就近年来国内外¹⁸F标记RGD 肽在肿瘤α_Ⅴβ₃受体显像中的研究进展作简要综述。