Langbein Thomas, Wurzer Alexander, Gafita Andrei, Robertson Andrew, Wang Hui, Arçay Ayça, Herz Michael, Wester Hans-Juergen, Weber Wolfgang A, Eiber Matthias
Department of Nuclear Medicine, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany;
Chair of Pharmaceutical Radiochemistry, Technical University of Munich, Garching, Germany.
J Nucl Med. 2022 May;63(5):742-745. doi: 10.2967/jnumed.121.262471. Epub 2021 Aug 12.
We investigated whether the time between synthesis and injection and the resulting decrease in specific activity affects the normal-organ and tumor uptake of the PSMA ligand F-rhPSMA-7.3 in patients with prostate cancer. The biodistribution of F-rhPSMA-7.3 on PET/CT scans obtained with a high specific activity (median, 178.9 MBq/µg; = 42) and a low specific activity (median, 19.3 MBq/µg; = 42) was compared. Tracer uptake by the parotid gland, submandibular gland, and spleen was moderately but significantly lower in the low-specific-activity group than in the high-specific-activity group (median SUV, 16.7 vs. 19.2; 18.1 vs. 22.3; and 7.8 vs. 9.6, respectively). No other statistically significant differences were found for normal organs or tumor lesions. A 10-fold decrease in specific activity has only minor effects on the biodistribution of F-rhPSMA-7.3. These findings suggest that F-labeled PSMA ligands can be centrally produced and shipped to PET clinics in a similar way to F-FDG.
我们研究了合成与注射之间的时间以及由此导致的比活度降低是否会影响前列腺癌患者中PSMA配体F-rhPSMA-7.3在正常器官和肿瘤中的摄取。比较了用高比活度（中位数，178.9 MBq/µg；n = 42）和低比活度（中位数，19.3 MBq/µg；n = 42）获得的PET/CT扫描上F-rhPSMA-7.3的生物分布。低比活度组中腮腺、颌下腺和脾脏的示踪剂摄取适度但显著低于高比活度组（中位数SUV分别为16.7对19.2；18.1对22.3；7.8对9.6）。在正常器官或肿瘤病变方面未发现其他统计学上的显著差异。比活度降低10倍对F-rhPSMA-7.3的生物分布仅有轻微影响。这些发现表明，F标记的PSMA配体可以像F-FDG一样在中心生产并运送到PET诊所。
