碘-123-碘右旋西替米特的人体剂量测定和生物分布：一种用于胆碱能毒蕈碱神经受体的单光子发射计算机断层扫描（SPECT）显像剂

Human dosimetry and biodistribution of iodine-123-iododexetimide: a SPECT imaging agent for cholinergic muscarinic neuroreceptors.

作者信息

Boundy K L, Barnden L R, Rowe C C, Reid M, Kassiou M, Katsifis A G, Lambrecht R M

机构信息

Department of Nuclear Medicine, Queen Elizabeth Hospital, Woodville, Australia.

出版信息

J Nucl Med. 1995 Jul;36(7):1332-8.

PMID:7790964

Abstract

UNLABELLED

Iodine-123-iododexetimide (IDEX) has recently been used for SPECT imaging of muscarinic cholinergic neuroreceptors (mAChR) in humans. We report the human radiation dosimetry, whole-body and normal cerebral distribution of IDEX.

METHODS

Serial whole-body planar and brain SPECT scans were performed over 24 hr in four normal subjects. Organ activity was calculated from attenuation-corrected geometric mean counts from ROIs drawn over visible organs. Thigh activity was used for background subtraction. Organ absorbed doses and effective dose were calculated using the MIRD schema. Brain SPECT was performed 6 hr postinjection in ten normal subjects. ROIs placed over cortical and subcortical structures were used to determine brain distribution.

RESULTS

The effective dose was 24.7 microSv/MBq. An average of 54% of IDEX remained in the body background. Decay-corrected brain uptake was 6.9% of injected dose at 1 hr, 8.6% at 6 hr and 8.1% at 24 hr. Regional brain distribution showed high uptake in striatum and cortex with low activity in thalamus and cerebellum. At 6 hr, activity relative to striatum was 70% for frontal and parietal cortex, 102% for occipital cortex, 54% for thalamus and 11% for cerebellum.

CONCLUSION

Iodine-123-IDEX produced high quality SPECT images with activity at 6 hr reflecting the known distribution of mAChR receptors. The favorable dosimetry of IDEX and high synthetic yield (50%-70%) suggest it to be a suitable agent for clinical studies.

摘要

未标记

碘 - 123 - 碘代右旋西替米特（IDEX）最近已用于人体毒蕈碱胆碱能神经受体（mAChR）的单光子发射计算机断层扫描（SPECT）成像。我们报告了IDEX的人体辐射剂量学、全身及正常脑内分布情况。

方法

对4名正常受试者在24小时内进行了系列全身平面和脑SPECT扫描。通过对可见器官上绘制的感兴趣区（ROI）经衰减校正后的几何平均计数来计算器官活性。使用大腿活性进行本底扣除。采用医学内照射剂量（MIRD）模式计算器官吸收剂量和有效剂量。对10名正常受试者在注射后6小时进行脑SPECT检查。通过放置在皮质和皮质下结构上的ROI来确定脑内分布。

结果

有效剂量为24.7微希沃特/兆贝可。平均54%的IDEX留在身体本底中。经衰变校正后，1小时时脑摄取量为注射剂量的6.9%，6小时时为8.6%，24小时时为8.1%。脑内区域分布显示纹状体和皮质摄取较高，丘脑和小脑活性较低。6小时时，相对于纹状体的活性，额叶和顶叶皮质为70%，枕叶皮质为102%，丘脑为54%，小脑为11%。