Pfob Christian H, Ziegler Sibylle, Graner Frank Philipp, Köhner Markus, Schachoff Sylvia, Blechert Birgit, Wester Hans-Jürgen, Scheidhauer Klemens, Schwaiger Markus, Maurer Tobias, Eiber Matthias
Department of Nuclear Medicine, Technische Universität München, Klinikum rechts der Isar; Ismaningerstrasse 22, 81675, Munich, Germany.
Chair of Pharmaceutical Radiochemistry, Department Chemie, Technische Universität München, Walther-Meissner-Str. 3, 85748, Garching, Germany.
Eur J Nucl Med Mol Imaging. 2016 Oct;43(11):1962-70. doi: 10.1007/s00259-016-3424-3. Epub 2016 May 20.
Positron emission tomography (PET) agents targeting the prostate-specific membrane antigen (PSMA) are currently under broad clinical and scientific investigation. (68)Ga-PSMA HBED-CC constitutes the first (68)Ga-labelled PSMA-inhibitor and has evolved as a promising agent for imaging PSMA expression in vivo. The aim of this study was to evaluate the whole-body distribution and radiation dosimetry of this new probe.
Five patients with a history or high suspicion of prostate cancer were injected intravenously with a mean of 139.8 ± 13.7 MBq of (68)Ga-PSMA HBED-CC (range 120-158 MBq). Four static skull to mid-thigh scans using a whole-body fully integrated PET/MR-system were performed 10 min, 60 min, 130 min, and 175 min after the tracer injection. Time-dependent changes of the injected activity per organ were determined. Mean organ-absorbed doses and effective doses (ED) were calculated using OLINDA/EXM.
Injection of a standard activity of 150 MBq (68)Ga-PSMA HBED-CC resulted in a median effective dose of 2.37 mSv (Range 1.08E-02 - 2.46E-02 mSv/MBq). The urinary bladder wall (median absorbed dose 1.64E-01 mGv/MBq; range 8.76E-02 - 2.91E-01 mGv/MBq) was the critical organ, followed by the kidneys (median absorbed dose 1.21E-01 mGv/MBq; range 7.16E-02 - 1.75E-01), spleen (median absorbed dose 4.13E-02 mGv/MBq; range 1.57E-02 - 7.32E-02 mGv/MBq) and liver (median absorbed dose 2.07E-02 mGv/MBq; range 1.80E-02 - 2.57E-02 mGv/MBq). No drug-related pharmacological effects occurred.
The use of (68)Ga-PSMA HBED-CC results in a relatively low radiation exposure, delivering organ doses that are comparable to those of other (68)Ga-labelled PSMA-inhibitors used for PET-imaging. Total effective dose is lower than for other PET-agents used for prostate cancer imaging (e.g. (11)C- and (18)F-Choline).
靶向前列腺特异性膜抗原（PSMA）的正电子发射断层扫描（PET）药物目前正在广泛的临床和科学研究中。（68）Ga-PSMA HBED-CC是首个（68）Ga标记的PSMA抑制剂，已发展成为一种在体内成像PSMA表达的有前景的药物。本研究的目的是评估这种新探针的全身分布和辐射剂量学。
5例有前列腺癌病史或高度怀疑患有前列腺癌的患者静脉注射平均139.8±13.7 MBq的（68）Ga-PSMA HBED-CC（范围120 - 158 MBq）。在注射示踪剂后10分钟、60分钟、130分钟和175分钟，使用全身完全集成的PET/MR系统进行四次从颅骨到大腿中部的静态扫描。确定每个器官注射活度的时间依赖性变化。使用OLINDA/EXM计算平均器官吸收剂量和有效剂量（ED）。
注射150 MBq标准活度的（68）Ga-PSMA HBED-CC导致中位有效剂量为2.37 mSv（范围1.08E - 02 - 2.46E - 02 mSv/MBq）。膀胱壁（中位吸收剂量1.64E - 01 mGv/MBq；范围8.76E - 02 - 2.91E - 01 mGv/MBq）是关键器官，其次是肾脏（中位吸收剂量1.21E - 01 mGv/MBq；范围7.16E - 02 - 1.75E - 01）、脾脏（中位吸收剂量4.13E - 02 mGv/MBq；范围1.57E - 02 - 7.32E - 02 mGv/MBq）和肝脏（中位吸收剂量2.07E - 02 mGv/MBq；范围1.80E - 02 - 2.57E - 02 mGv/MBq）。未发生与药物相关的药理作用。
使用（68）Ga-PSMA HBED-CC导致相对较低的辐射暴露，所提供的器官剂量与用于PET成像的其他（68）Ga标记的PSMA抑制剂相当。总有效剂量低于用于前列腺癌成像的其他PET药物（例如（11）C-和（18）F-胆碱）。
