Cutler P D, Schwarz S W, Anderson C J, Connett J M, Welch M J, Philpott G W, Siegel B A
Division of Radiation Sciences, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
J Nucl Med. 1995 Dec;36(12):2363-71.
We present biodistribution and dosimetry results for 64Cu-benzyl-TETA-MAb 1A3 from 15 human subjects injected with this tracer as determined by serial PET imaging of the torso.
PET imaging was used to quantify in vivo tracer biodistribution at two time points after injection. Absorbed dosimetry calculated using MIRD-11 and the updated MIRDOSE3 was compared with estimates obtained using rat biodistribution data.
By measuring activity concentrations in the torso, and extrapolating for the whole body using standard organ and tissue volumes, we were able to account for 93% of the injected radiopharmaceutical over a range of imaging times from 0 to 36 hr postinjection. Based on PET imaging and the MIRD-11 schema, the liver and spleen are the critical organs with average absorbed doses of 0.12 and 0.10 mGy/MBq (0.44 and 0.39 rad/mCi). The revised MIRDOSE3 scheme yields similar values for these and other organs but also results in a dose of 0.14 mGy/MBq (0.53 rad/mCi) to the heart wall. In the rat, the large intestine is the critical organ at 0.14 mGy/MBq (0.52 rad/mCi), while liver and kidneys each receive 0.11 mGy/MBq (0.41 rad/mCi). Some disparities in absorbed doses determined by these methods are evident but are a result of dissimilar biodistributions in rats and humans. For most organs, rat extrapolated values are higher than the human measurements with PET.
This study shows that torso PET imaging can quantitatively measure the whole-body biodistribution of a radiopharmaceutical as long as it has relatively slow pharmacokinetics.
我们展示了15名注射了示踪剂64Cu-苄基-TETA-MAb 1A3的人类受试者的生物分布和剂量测定结果，这些结果通过对躯干进行连续PET成像来确定。
PET成像用于在注射后两个时间点对体内示踪剂生物分布进行定量。使用MIRD-11和更新后的MIRDOSE3计算的吸收剂量与使用大鼠生物分布数据获得的估计值进行比较。
通过测量躯干中的活性浓度，并使用标准器官和组织体积外推至全身，我们能够在注射后0至36小时的一系列成像时间内，解释93%的注射放射性药物。基于PET成像和MIRD-11模式，肝脏和脾脏是关键器官，平均吸收剂量分别为0.12和0.10 mGy/MBq（0.44和0.39 rad/mCi）。修订后的MIRDOSE3方案对这些器官和其他器官得出了相似的值，但也得出心脏壁的剂量为0.14 mGy/MBq（0.53 rad/mCi）。在大鼠中，大肠是关键器官，剂量为0.14 mGy/MBq（0.52 rad/mCi），而肝脏和肾脏各接受0.11 mGy/MBq（0.41 rad/mCi）。这些方法确定的吸收剂量存在一些差异，但这是大鼠和人类生物分布不同的结果。对于大多数器官，大鼠外推值高于PET测量的人体值。
本研究表明，只要放射性药物的药代动力学相对较慢，躯干PET成像就可以定量测量其全身生物分布。
