The Influence of Specific Activity on the Biodistribution of 18 F-rhPSMA-7.3: A Retrospective Analysis of Clinical PET Data

The Journal of Nuclear Medicine

article

Thomas Langbein¹  Alexander Wurzer²  Andrei Gafita¹  Andrew Robertson¹  Hui Wang¹  Ayça Arçay¹  Michael Herz¹  Hans-Juergen Wester²  Wolfgang A. Weber¹  Matthias Eiber¹ 

[1] Department of Nuclear Medicine, Klinikum rechts der Isar, School of Medicine, Technical University of Munich;Chair of Pharmaceutical Radiochemistry, Technical University of Munich;Ahmanson Translational Theranostics Division, Department of Molecular and Medical Pharmacology, UCLA;Department of Nuclear Medicine, Akdeniz University

关键词: PSMA;    PET/CT;    biodistribution;    molar activity;    18F;   

DOI  :  10.2967/jnumed.121.262471

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

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 18F-rhPSMA-7.3 in patients with prostate cancer. Methods: The biodistribution of 18F-rhPSMA-7.3 on PET/CT scans obtained with a high specific activity (median, 178.9 MBq/µg; n = 42) and a low specific activity (median, 19.3 MBq/µg; n = 42) was compared. Results: 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 SUVmean, 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. Conclusion: A 10-fold decrease in specific activity has only minor effects on the biodistribution of 18F-rhPSMA-7.3. These findings suggest that 18F-labeled PSMA ligands can be centrally produced and shipped to PET clinics in a similar way to 18F-FDG.

【 授权许可】

CC BY