99mTc-TRODAT-1内照射辐射吸收剂量的计算

为估测^99mTc-TRODAT-1在全身靶器官的内照射辐吸收剂量及生物学分布，对3例帕金森病患者（PD）、2例原发性震颤（ET）患者静脉注射^99mTc-TRODAT-1后，用双探头SPECT采集24h内系列全身前、后位图像；利用ROI技术获各时相全身各脏器的摄取放射性活度，采用Microcal Origin5.0应用程序中的非线性拟合方法得到全脏器的时间－放射性曲线，通过各种源器官的累积活度计算出放射性核素的滞留时间，然后由美国MIRDOSE3．1应用程序得到各靶器官的内照射辐照吸收剂量，另外，注药后3h离断层显像，实验结果显示，^99mTc-TRODAT-1全身各脏器内照射辐射吸收剂量均较小，脑断层显像，纹状体影像清晰。^99mTc-TRODAT-1人体应用安全，是一种优良的多巴胺转运体（DAT）显像剂。

Calculation of the internal radiation absorbed dose of 99mTc-TRODAT-1

To evaluate the radiobiodistribution and internal dosimetry of 99mTc-TRODAT-1 in human target organs. Three patients with Pakinson' s disease (PD) and two patients with essential tremor (ET) were included. After injection of 99mTc-TRODAT-1 intravenously, serial whole body scans were aquired during the following 24h by dual-head SPECT. Radioactivity uptakes were estimated applying ROI technique and radioactivity-time curves in target organs were obtained with non-linear regression analysis in terms of Microcal Origin 5.0 software. Residence time was calculated from the accumulative activity. All data of the residence times were input to the MIRDOSE 3.1 software to create the organ-absorbed dose. Brain tomography for each patient was performed 3h post injection. The experimental results showed that the internal absorbed dose from 99mTc-TRODAT-1 in target organs was small and the striatum was clearly imaged. Also, demonstrates that 99mTc-TRODAT-1 is a safe and ideal radio tracer to visualize the changes of dopamine transporter in striatum.