Booij J, Busemann Sokole E, Stabin M G, Janssen A G, de Bruin K, van Royen E A
Graduate School of Neurosciences, Department of Nuclear Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
Eur J Nucl Med. 1998 Jan;25(1):24-30.
This study reports on the biodistribution and radiation dosimetry of iodine-123-labelled N-omega-(flu- oropropyl)-2beta-carbomethoxy-3beta-(4-iodophenyl)tropane ([123I]FP-CIT), a promising radioligand for the imaging of dopamine transporters. In 12 healthy volunteers, conjugate whole-body scans were performed up to 48 h following intravenous injection of approximately 100 MBq [123I]FP-CIT. Attenuation correction was performed using a transmission whole-body scan obtained prior to injection of the radioligand, employing a 123I flood source. Blood samples were taken and urine was freely collected up to 48 h after injection of the radiotracer. For each subject, the percentage of injected activity measured in regions of interest over brain, striatum, lungs and liver were fitted to a multicompartmental model to give time-activity curves. The cumulative urine activity curve was used to model the urinary excretion rate and, indirectly, to predict faecal excretion. Using the MIRD method, nine source organs were considered in estimating absorbed radiation doses for organs of the body. The images showed rapid lung uptake and hepatobiliary excretion. Diffuse uptake and retention of activity was seen in the brain, especially in the striatum. At 48 h following the injection of [123I]FP-CIT, mean measured urine excretion was 60%+/-9% (SD), and mean predicted excretion in faeces was 14%+/-1%. In general, the striatum received the highest absorbed dose (average 0.23 mGy/MBq), followed by the urinary bladder wall (average 0.054 mGy/MBq) and lungs (average 0.043 mGy/MBq). The average effective dose equivalent of [123I]FP-CIT was estimated to be 0.024 mSv/MBq. The amount of [123I]FP-CIT required for adequate dopamine transporter imaging results in an acceptable effective dose equivalent to the patient.
本研究报告了碘-123标记的N-ω-（氟丙基）-2β-甲氧羰基-3β-（4-碘苯基）托烷（[123I]FP-CIT）的生物分布和辐射剂量学，它是一种用于多巴胺转运体成像的有前景的放射性配体。在12名健康志愿者中，静脉注射约100 MBq [123I]FP-CIT后进行长达48小时的全身联合扫描。使用在注射放射性配体之前获得的全身透射扫描进行衰减校正，采用123I泛源。在注射放射性示踪剂后采集血样并自由收集尿液直至48小时。对于每个受试者，在脑、纹状体、肺和肝的感兴趣区域测量的注射活度百分比被拟合到一个多室模型以给出时间-活度曲线。累积尿活度曲线用于模拟尿排泄率，并间接预测粪便排泄。使用MIRD方法，在估计身体各器官的吸收辐射剂量时考虑了九个源器官。图像显示肺摄取迅速且有肝胆排泄。在脑中可见弥漫性摄取和活度滞留，尤其是在纹状体。注射[123I]FP-CIT后48小时，平均测量的尿排泄为60%±9%（标准差），平均预测的粪便排泄为14%±1%。一般来说，纹状体接受的吸收剂量最高（平均0.23 mGy/MBq），其次是膀胱壁（平均0.054 mGy/MBq）和肺（平均0.043 mGy/MBq）。[123I]FP-CIT的平均有效剂量当量估计为0.024 mSv/MBq。获得足够的多巴胺转运体成像所需的[123I]FP-CIT量导致对患者可接受的有效剂量当量。
