Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
Department of Oncology, University of Turku and Turku University Hospital, Turku, Finland.
Eur J Nucl Med Mol Imaging. 2021 Oct;48(11):3723-3731. doi: 10.1007/s00259-021-05346-8. Epub 2021 Apr 12.
This phase 1 open-label study evaluated the uptake kinetics of a novel theranostic PET radiopharmaceutical, F-rhPSMA-7.3, to optimise its use for imaging of prostate cancer.
Nine men, three with high-risk localised prostate cancer, three with treatment-naïve hormone-sensitive metastatic disease and three with castration-resistant metastatic disease, underwent dynamic 45-min PET scanning of a target area immediately post-injection of 300 MBq F-rhPSMA-7.3, followed by two whole-body PET/CT scans acquired from 60 and 90 min post-injection. Volumes of interest (VoIs) corresponding to prostate cancer lesions and reference tissues were recorded. Standardised uptake values (SUV) and lesion-to-reference ratios were calculated for 3 time frames: 35-45, 60-88 and 90-118 min. Net influx rates (K) were calculated using Patlak plots.
Altogether, 44 lesions from the target area were identified. Optimal visual lesion detection started 60 min post-injection. The F-rhPSMA-7.3 signal from prostate cancer lesions increased over time, while reference tissue signals remained stable or decreased. The mean (SD) SUV (g/mL) at the 3 time frames were 8.4 (5.6), 10.1 (7) and 10.6 (7.5), respectively, for prostate lesions, 11.2 (4.3), 13 (4.8) and 14 (5.2) for lymph node metastases, and 4.6 (2.6), 5.7 (3.1) and 6.4 (3.5) for bone metastases. The mean (SD) lesion-to-reference ratio increases from the earliest to the 2 later time frames were 40% (10) and 59% (9), respectively, for the prostate, 65% (27) and 125% (47) for metastatic lymph nodes and 25% (19) and 32% (30) for bone lesions. Patlak plots from lesion VoIs signified almost irreversible uptake kinetics. K, SUV and lesion-to-reference ratio estimates showed good agreement.
F-rhPSMA-7.3 uptake in prostate cancer lesions was high. Lesion-to-background ratios increased over time, with optimal visual detection starting from 60 min post-injection. Thus, F-rhPSMA-7.3 emerges as a very promising PET radiopharmaceutical for diagnostic imaging of prostate cancer.
NCT03995888 (24 June 2019).
本研究为一项新型放射性诊疗用正电子发射断层扫描（PET）放射性药物 F-rhPSMA-7.3 的Ⅰ期开放性研究，旨在优化其在前列腺癌成像中的应用，以评估其摄取动力学。
9 名男性患者（3 名局部高危前列腺癌患者、3 名未经治疗的激素敏感转移性疾病患者和 3 名去势抵抗性转移性疾病患者）在注射 300MBq F-rhPSMA-7.3 后立即进行 45 分钟的目标区域动态 PET 扫描，随后在注射后 60 分钟和 90 分钟进行两次全身 PET/CT 扫描。记录前列腺癌病灶和参考组织的感兴趣区（VOI）。计算 3 个时间框架（35-45min、60-88min 和 90-118min）的标准化摄取值（SUV）和病灶与参考比值。使用 Patlak 图计算净摄取率（K）。
共在目标区域发现 44 个病灶。60min 后开始进行最佳的视觉病灶检测。前列腺癌病灶的 F-rhPSMA-7.3 信号随时间增加，而参考组织信号保持稳定或减少。3 个时间框架的平均（SD）SUV（g/ml）分别为前列腺病灶 8.4（5.6）、10.1（7）和 10.6（7.5）、淋巴结转移灶 11.2（4.3）、13（4.8）和 14（5.2）、骨转移灶 4.6（2.6）、5.7（3.1）和 6.4（3.5）。从最早到后两个时间框架，病灶与参考比值的平均（SD）增加分别为 40%（10）和 59%（9），用于前列腺，65%（27）和 125%（47）用于转移性淋巴结，25%（19）和 32%（30）用于骨病变。病灶 VOI 的 Patlak 图表明摄取动力学几乎是不可逆的。K、SUV 和病灶与参考比值的估计值具有良好的一致性。
F-rhPSMA-7.3 在前列腺癌病灶中的摄取量很高。病灶与背景的比值随时间增加，60min 后开始进行最佳的视觉检测。因此，F-rhPSMA-7.3 作为一种很有前途的前列腺癌诊断成像用正电子发射断层扫描放射性药物出现。
NCT03995888（2019 年 6 月 24 日）。
