钴-55和钴-57的药代动力学与剂量测定

Pharmacokinetics and dosimetry of cobalt-55 and cobalt-57.

作者信息

Jansen H M, Knollema S, van der Duin L V, Willemsen A T, Wiersma A, Franssen E J, Russel F G, Korf J, Paans A M

机构信息

Department of Neurology, University of Groningen, The Netherlands.

出版信息

J Nucl Med. 1996 Dec;37(12):2082-6.

PMID:8970539

Abstract

UNLABELLED

The isotopes 55Co and 57Co have been evaluated for PET and SPECT imaging in several clinical brain studies. For clinical application of cobalt, it is important to know the delivered radiation dose. The biodistribution of 55Co in both rat and humans after intravenous (bolus)-administration was studied. Based on pharmacokinetic data, radiation dose calculations according to the MIRD system are presented. By combining present measurements with literature data on 60CoCl2, the radiation dose delivered by 56CoCl2 (T1/2 78.8 days) and 57CoCl2 (T1/2 = 270 days) could be assessed.

METHODS

Whole-body Co-PET was performed in two healthy volunteers and one rat after intravenous injection of 37 and 3.7 MBq (1 resp. 0.1 mCi) 55Co, respectively. Blood samples were withdrawn during 300 min in humans. In seven rats the 55Co-biodistribution was determined by postmortem analysis. The residence time of the liver (critical organ) was determined in rats and humans. Blood partition-data of 55Co were assessed resulting in basic pharmacokinetic data in humans. Based on these kinetic data, radiation dose was calculated using the MIRD protocol.

RESULTS

In both the humans and the rat, the liver and bladder retained the highest fractions of 55Co (about 50% resp. 40% of the administered dose). The liver residence time in humans was 8.6 hr. The free fraction 55Co in the human plasma was at maximum 12%. The total-body mean transit time was 152 min. The volume of the central compartment = 2.8 liter and the steady-state distribution volume = 48 liter.

CONCLUSION

From these results, according to the WHO recommendations for class II studies, 22.2 MBq (0.6 mCi) 55Co and 14.8 MBq (0.4 mCi) 57Co (excluding any radionuclide contamination) can be used.

摘要

未标注

在多项临床脑部研究中，已对同位素(^{55}Co)和(^{57}Co)用于正电子发射断层扫描（PET）和单光子发射计算机断层扫描（SPECT）成像进行了评估。对于钴在临床中的应用，了解所给予的辐射剂量很重要。研究了静脉推注给药后(^{55}Co)在大鼠和人体中的生物分布。根据药代动力学数据，给出了根据医学内照射剂量（MIRD）系统进行的辐射剂量计算。通过将当前测量结果与关于(^{60}CoCl_2)的文献数据相结合，可以评估(^{56}CoCl_2)（半衰期78.8天）和(^{57}CoCl_2)（半衰期 = 270天）所给予的辐射剂量。

方法

分别向两名健康志愿者和一只大鼠静脉注射37和3.7兆贝可（分别为1和0.1毫居里）(^{55}Co)后，进行全身钴PET检查。在人体中300分钟内采集血样。在七只大鼠中，通过死后分析确定(^{55}Co)的生物分布。确定了大鼠和人体中肝脏（关键器官）的滞留时间。评估了(^{55}Co)的血液分配数据，得出人体的基本药代动力学数据。基于这些动力学数据，使用MIRD方案计算辐射剂量。