Division of Nuclear Medicine, Russell H. Morgan Department of Radiology, Johns Hopkins University, Baltimore, Maryland 21287, USA.
J Nucl Med. 2010 Oct;51(10):1592-9. doi: 10.2967/jnumed.110.077669. Epub 2010 Sep 16.
Prior estimates of radiation-absorbed doses from (82)Rb, a frequently used PET perfusion tracer, yielded discrepant results. We reevaluated (82)Rb dosimetry using human in vivo biokinetic measurements.
Ten healthy volunteers underwent dynamic PET/CT (6 contiguous table positions, each with separate (82)Rb infusion). Source organ volumes of interest were delineated on the CT images and transferred to the PET images to obtain time-integrated activity coefficients. Radiation doses were estimated using OLINDA/EXM 1.0.
The highest mean absorbed organ doses (μGy/MBq) were observed for the kidneys (5.81), heart wall (3.86), and lungs (2.96). Mean effective doses were 1.11 ± 0.22 and 1.26 ± 0.20 μSv/MBq using the tissue-weighting factors of the International Commission on Radiological Protection (ICRP), publications 60 and 103, respectively.
Our current (82)Rb dosimetry suggests reasonably low radiation exposure. On the basis of this study, a clinical (82)Rb injection of 2 × 1,480 MBq (80 mCi) would result in a mean effective dose of 3.7 mSv using the weighting factors of the ICRP 103-only slightly above the average annual natural background exposure in the United States (3.1 mSv).
先前对（82）Rb 的辐射吸收剂量的估计值，（82）Rb 是一种常用于 PET 灌注示踪剂的元素，得到了不一致的结果。我们使用人体体内生物动力学测量重新评估了（82）Rb 的剂量测定。
十名健康志愿者接受了动态 PET/CT（6 个连续的体位，每个体位都有单独的（82）Rb 输注）。在 CT 图像上划定感兴趣的源器官体积，并将其转移到 PET 图像上以获得时间积分的活性系数。使用 OLINDA/EXM 1.0 估计辐射剂量。
观察到最高的平均吸收器官剂量（μGy/MBq）为肾脏（5.81）、心脏壁（3.86）和肺部（2.96）。使用国际辐射防护委员会（ICRP）的组织权重因子 60 和 103，平均有效剂量分别为 1.11 ± 0.22 和 1.26 ± 0.20 μSv/MBq。
我们目前的（82）Rb 剂量测定值表明辐射暴露相当低。根据这项研究，使用 ICRP 103 仅加权因子的临床（82）Rb 注射 2×1480 MBq（80 mCi）将导致平均有效剂量为 3.7 mSv，略高于美国的平均年自然背景暴露量（3.1 mSv）。
