153Sm─EDTMP注射液活度测量标准化研究

治疗用放射性药品活度与其用药安全性和有效直接相关。为了确保153Sm─EDTMP注射液用药安全有效,本工作对使用活度计测量Na188ReO4 溶液活度的方法进行了标准化研究。利用4π液闪、4πβ-γ符合方法,通过四家单位6套装置测量,确定153Sm─EDTMP注射液标准源的活度量值;再利用已知活度的标准源,对使用活度计测量153Sm─EDTMP注射液活度的方法进行了标准化研究,确定测量条件。     

89SrCl2注射液活度测量的标准化研究

为保障89SrCl2注射液用药剂量准确统一,本工作进行了89SrCl2注射液活度测量标准化研究.利用4π液闪、4πβ-γ符合方法,通过四家单位6套装置测量确定其活度标准量值.以4π电离室法为标准方法,对标准样品规格、样品量影响以及标定方法等进行系统研究,最后对三个地区9个实验室的16台活度计进行质控检验.结果表明,85%CRC系列活度计(CRC-15R和CRC-30BC)均在标准值的±5%以内.     

液闪三双符合比方法测量~(99)Tc放射性活度

液闪三双符合比(TDCR)方法采用3个光电倍增管对称放置的液闪计数器,利用三管符合和三对两管符合的计数计算液闪探测效率,从而得到放射性活度,不需要使用标准源对仪器进行效率刻度,是一种放射性活度绝对测量方法。由于具有无自吸收、制源简单、操作简便、一致性好等优点,已广泛应用于纯β衰变核素放射性活度的测量。介绍了液闪TDCR方法的基本原理和液闪TDCR活度测量装置,并绝对测量了纯β衰变核素99Tc放射性活度,测量不确定度小于0.3%。     

放射性药物~(188)Re标记DTPA的制备和在大鼠体内的分布

球囊导管内充盈β放射性核素防治经皮冠状动脉成形术(PTCA)后再狭窄是一种崭新的技术, 其中,188Re是一种常用的放射性核素。为了尽可能降低在万一球囊破裂的情况下高剂量放射性对人体的损害,利用二乙三胺五醋酸(DTPA)迅速从泌尿系统排出的特点,通过探索188Re标记DTPA的方法和条件,成功地制备了188Re-DTPA化合物,并研究出最佳的标记条件从而使标记产率达到90%以上。188Re-DTPA和188ReO4-在大鼠体内分布的研究结果显示,甲状腺和胃肠道的放射性水平188Re-DTPA组明显低于188ReO4-组,188Re-DTPA经肾脏排泄明显快于188ReO4-,用MIRDOSE 3.0软件估算体内重要脏器的吸收剂量同样也显示了这一结果。188Re-DTPA组和188ReO4-组甲状腺的吸收剂量分别为0.041 nGy/Bq和0.563 nGy/Bq,胃的吸收剂量分别为0.043 nGy/Bq和0.118 nGy/Bq。因此,实验结果认为在血管内照射治疗中188Re-DTPA明显优于188ReO4-。     

放射性药物^188Re标记DTPA的制备和在大鼠体内的分布

球囊导管内充盈β放射性核素防治经皮冠状动脉成形术(PTCA)后再狭窄是一种崭新的技术，其中，^188Re是一种常用的放射性核素。为了尽可能降低在万一球囊破裂的情况下高剂量放射性对人体的损害，利用二乙三胺五醋酸(DTPA)迅速从泌尿系统排出的特点，通过探索^188Re标记DTPA的方法和条件，成功地制备了^188Re-DTPA化合物，并研究出最佳的标记条件从而使标记产率达到90％以上。^188Re-DTPA和^188ReO4^-在大鼠体内分布的研究结果显示，甲状腺和胃肠道的放射性水平^188Re-DTPA组明显低于^188ReO4^-组，^188Re-DTPA经肾脏排泄明显快于^188ReO4^-，用MIRDOSE3．0软件估算体内重要脏器的吸收剂量同样也显示了这一结果。^188Re-DTPA组和^188ReO4^-组甲状腺的吸收剂量分别为0．041nGy/Bq和O．563nGy／Bq，胃的吸收剂量分别为0．043nGy／Bq和0．118nGy／Bq。因此，实验结果认为在血管内照射治疗中’~Re-DTPA明显优于^188ReO4^-。     

^131I放射性活度的相对测量

本文报道选用与样品源相同的核素作标准源,运用稳定性较好的探测仪器,控制样品源与标准源测量时的相同几何条件,进行比对源~(131)I活度的相对测量,~(131)I测量值为672.6±4.7Bqmg~(-1),与4πβ-γ符合活度基准测量值670.8±2.7Bqmg~(-1)和各比对单位上报结果平均活度671.1±1.7Bqmg~(-1)相对误差均低于3‰,比对结果颇为理想,说明相对测量方法乃是目前基层放射性监测单位测量放射性活度行之有效的方法。     

~(188)Re-DTPA的制备及生物分布研究

以SnCl2·2H2O为还原剂,还原188ReO-4并与DTPA直接配合获得188Re DTPA,优化了标记反应条件;对188Re DTPA和Na188ReO4在正常小鼠体内分布进行了比较。实验结果表明,在最佳标记条件下,188Re DT PA的标记率大于95%;标记物体外稳定,经生理盐水稀释后,其稳定性下降。188Re DTPA在小鼠体内血液清除快,在甲状腺、胃及其它组织中的摄取率明显低于Na188ReO4,主要经肾脏通过尿液排出体外。     

相加峰法测量125Ⅰ活度的随机相加修正研究

相加峰法是¹²⁵Ⅰ活度绝对测量最常用方法。相加峰法活度测量需要考虑计数率依赖的脉冲堆积随机相加效应影响。随机相加影响大小与设备性能有关。文章采用同批溶液制备不同活度的标准源,用归一比活度与相加峰计数率的拟合关系,以及二者的线性外推结果,得到了符合相加影响规律,确定了相加峰计数率与随机相加修正因子之间的依赖关系。此工作对掌握测量设备性能,准确计量¹²⁵Ⅰ具有重要意义。     

用灵敏值确定纯β核素的液闪测量效率

纯β核素液闪测量技术应用广泛,实际工作中往往需要确定核素的测量效率;但除~3H、~(14)C等半衰期较长的核素外,多无系列猝灭标准源,给工作带来很多不便。本文根据国外有关方面研究,做了以~3H标准源为基准、通过理论计算求出其它纯β核素在均相条件下的测量效率和猝灭校正曲线,进而求得放射性的活度。本方法使用简便、结果可靠,实用性强。     

188Re-MAG3的制备及动物体内评价

本工作着重研究了可用于PTCA(Percutaneous transluminal coronary angioplasty)后冠状动脉再狭窄防治的放射性标记化合物^188Re-MAG3的制备,并与Na^188ReO4的小鼠体内生物分布加以比较。结果表明,在 TechneScan MAG3锝药盒中加入酒石酸亚锡,控制标记条件,^188Re-MAG3的标记率可大于98％。^188Re-MAG3在小鼠体内的血液清除明显快于Na^188ReO4,甲状腺和胃肠道吸收明显低于Na^188ReO4,标记物主要经肾脏通过尿液排出体外。为降低PTCA后冠脉再狭窄的发生率,与Na^188ReO4相比,^188Re-MAG3更适于临床应用。     

^188 Re labeled MPEG-modified superparamagnetic nanogels：preparation and preliminary application in mice

Superparamagnetic poly（acrylamide） magnetic nanogels produced via photochemical method have been developed. After Hoffmann degradation of carbonyl, the nanogels with amino groups, or poly（acrylamide-vinyl amine） magnetic nanogels, were also obtained. And the magnetic nanogels were further modified by methoxy poly（ethylene glycol） （MPEG） for higher dispersibility and stability. The MPEG-modified magnetic nanogels were characterized by X-ray diffraction （XRD）, photo correlation spectroscopy （PCS） and scanning electron microscopy （SEM）, respectively. The MPEG-modified magnetic nanogels were labeled by ^188 Re radiopharmaceuticals and intravenously injected into tails of mice in the presence and absence of a 0.5 T external magnetic field targeted on the bellies. The radioactivity distribution was monitored in vivo. In the absence of magnetic field, the radioactivity was mainly distributed in liver, spleen, kidney, stomach and lung. In the presence of the magnetic field, the radioactivity was mainly accumulated on the targeted point, verifying the magnetically targeted character.     

188Re直接标记抗体方法研究

以2-巯基乙醇作为抗体的还原剂,葡萄糖酸钠作为中间弱配体,在pH5．0的条件下,以SnCl2快速还原”。ReO4^-,进行了单克隆抗体IgG的直接标记。探讨了影响标记率的因素。结果显示,优化后的标记条件为pH5．0,室温下标记3h,SnCl2用量2．66μmol,葡萄糖酸钠用量80μmol。该方法操作步骤简单方便,标记率较高,为94．4％±0．7％,标记物不需分离纯化,且有良好的体外稳定性,室温下可稳定保存8h。     

Remote calibration of ionization chambers for radioactivity calibration

A new calibration technique, referred to as e-trace, has been developed by the National Institute of Advanced Industrial Science and Technology (AIST). The e-trace technique enables rapid remote calibration of measurement equipment and requires minimal resources. We calibrated radioisotope calibrators of the Japan Radioisotope Association (JRIA) and the Nishina Memorial Cyclotron Center (NMCC) remotely and confirmed that remote calibration provided results that are consistent with the results obtained by existing methods within the limits of uncertainty. Accordingly, e-trace has been approved as the standard calibration method at AIST. We intend to apply remote calibration to radioisotope calibrators in hospitals and isotope facilities.     

放射性药物内照射剂量计算软件(Ⅰ)--源器官衰变数的计算

为快速、准确的计算核衰变数，本工作在简要介绍计算模式的基础上提出了一个用VB6.0编制的专门软件BIKNC1.0。验算结果表明，该软件可用于实际计算核衰变数。     

Application of the Monte Carlo method to the analysis of measurement geometries for the calibration of a HP Ge detector in an environmental radioactivity laboratory

A gamma spectrometer including an HP Ge detector is commonly used for environmental radioactivity measurements. The efficiency of the detector should be calibrated for each geometry considered. Simulation of the calibration procedure with a validated computer program is an important auxiliary tool for environmental radioactivity laboratories. The MCNP code based on the Monte Carlo method has been applied to simulate the detection process in order to obtain spectrum peaks and determine the efficiency curve for each modelled geometry. The source used for measurements was a calibration mixed radionuclide gamma reference solution, covering a wide energy range (50-2000 keV). Two measurement geometries - Marinelli beaker and Petri boxes - as well as different materials - water, charcoal, sand - containing the source have been considered. Results obtained from the Monte Carlo model have been compared with experimental measurements in the laboratory in order to validate the model.     

Dosimetric calibration of solid state detectors with low energy β sources

A PTW Optidos plastic scintillation and a PTW natural diamond detectors were calibrated in terms of absorbed dose to water with β fields produced by ⁹⁰Sr + ⁹⁰Y and ⁸⁵Kr reference sources. Each source was characterized at the Italian National Metrological Institute - the Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti of ENEA (ENEA-INMRI) - for two different series, 1 and 2, of ISO reference β-particle radiation fields. Beam flattening filters were used for the series 1 β fields to give uniform absorbed dose rates over a large area at a source-to-reference plane distance of 30 cm. The series 2 β fields were produced at source-to-reference plane distance of 10 cm, without the beam flattening filters, in order to obtain higher absorbed dose rates.The reference absorbed dose rate values were directly determined by the Italian national standard for β-particle dosimetry (a PTW extrapolation ionization chamber) for the series 1 β fields and by a calibrated transfer standard chamber, (a Capintec thin fixed-volume parallel plate ionization chamber) for the series 2 β fields. Finally the two solid state detectors were calibrated in terms of absorbed dose to water with the series 2 β field.The expanded uncertainties of the calibration coefficients obtained for the plastic scintillation dosimeter were 10% and 12% (2SD) for the ⁹⁰Sr + ⁹⁰Y and the ⁸⁵Kr sources, respectively. The expanded uncertainties obtained for the diamond dosimeter were 10% (2SD) and 16% (2SD) for the ⁹⁰Sr + ⁹⁰Y and the ⁸⁵Kr sources, respectively.The good results obtained with the ⁹⁰Sr + ⁹⁰Y and the ⁸⁵Kr β sources encourage to implement this procedure to calibrate this type of detectors at shorter distances and with other β sources of interest in brachytherapy, for example the ¹⁰⁶Ru source.     

Synthesis of highly concentrated,carrier free ^188Re—mercaptoacetyltriglycine

Chelation of ^188Re to compounds such as MAG3 will further reduce the radiation dose to the patient in case of balloon rupture through the rapid excretion from the body.In order to prepae highly concentrated,carrier free ^188Re-MAG3,Sbenzoyl mercaptoacetyltriglycine(S-Bz-MAG3) was synthesized.labeled with carrier free ^188Re.the overall yield of S-Bz-MAG3 is higher than those published in the literature,Dependence of the labeling yield of ^188Re-MAG3 upon concentrations of reducing agent,pH,reaction time,etc.was examined and optimum conditions were confirmed.The concentration procedure was succeeded with Sep-Pak C18 cartridge to obtain highly concentrated ^188Re-MAG3.In the case of optimun conditions.the labeling yield of 188Re-MAG3 was more than 98%.Radiochemical purity of ^188ReMAG3 was more than 92% after 24 hour storage at room temperature.     

188W-188Re发生器的制备和质量控制

为了优化^188W-^188Re发生器的制备工艺，对^188W-^188Re发生器的制备及质量控制进行了研究，并测定了^188W在Al2O3上的吸附容量。结果表明：发生器淋洗效率大于85％，^188W漏穿率小于10^-6，^188Re放射性核纯度大于99.90％，放化纯度大于99％，洗脱液细菌、细菌内毒素含量合格。