In:
Molecular Imaging and Biology, Springer Science and Business Media LLC, Vol. 24, No. 1 ( 2022-02), p. 115-125
Abstract:
We present here a Zr-89-labeled inhibitor of prostate-specific membrane antigen (PSMA) as a complement to the already established F-18- or Ga-68-ligands. Procedures The precursor PSMA-DFO (ABX) was used for Zr-89-labeling. This is not an antibody, but a peptide analogue of the precursor for the production of [ 177 Lu]Lu-PSMA-617. The ligand [ 89 Zr]Zr-PSMA-DFO was compared with [ 68 Ga]Ga-PSMA-11 and [ 18 F]F-JK-PSMA-7 in vitro by determination of the K d value, cellular uptake, internalization in LNCaP cells, biodistribution studies with LNCaP prostate tumor xenografts in mice, and in vivo by small-animal PET imaging in LNCaP tumor mouse models. A first-in-human PET was performed with [ 89 Zr]Zr-PSMA-DFO on a patient presenting with a biochemical recurrence after brachytherapy and an ambiguous intraprostatic finding with [ 18 F]F-JK-PSMA-7 but histologically benign cells in a prostate biopsy 7 months previously. Results [ 89 Zr]Zr-PSMA-DFO was prepared with a radiochemical purity ≥ 99.9% and a very high in vitro stability for up to 7 days at 37 °C. All radiotracers showed similar specific cellular binding and internalization, in vitro and comparable tumor uptake in biodistribution experiments during the first 5 h. The [ 89 Zr]Zr-PSMA-DFO achieved significantly higher tumor/background ratios in LNCaP tumor xenografts (tumor/blood: 309 ± 89, tumor/muscle: 450 ± 38) after 24 h than [ 68 Ga]Ga-PSMA-11 (tumor/blood: 112 ± 57, tumor/muscle: 58 ± 36) or [ 18 F]F-JK-PSMA-7 (tumor/blood: 175 ± 30, tumor/muscle: 114 ± 14) after 4 h ( p 〈 0.01). Small-animal PET imaging demonstrated in vivo that tumor visualization with [ 89 Zr]Zr-PSMA-DFO is comparable to [ 68 Ga]Ga-PSMA-11 or [ 18 F]F-JK-PSMA-7 at early time points (1 h p.i.) and that PET scans up to 48 h p.i. clearly visualized the tumor at late time points. A late [ 89 Zr]Zr-PSMA-DFO PET scan on a patient with biochemical recurrence (BCR) had demonstrated intensive tracer accumulation in the right (SUV max 13.25, 48 h p.i.) and in the left prostate lobe (SUV max 9.47), a repeat biopsy revealed cancer cells on both sides. Conclusion [ 89 Zr]Zr-PSMA-DFO is a promising PSMA PET tracer for detection of tumor areas with lower PSMA expression and thus warrants further clinical evaluation.
Type of Medium:
Online Resource
ISSN:
1536-1632
,
1860-2002
DOI:
10.1007/s11307-021-01632-x
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2022
detail.hit.zdb_id:
2079211-6
SSG:
12
