An in silico study on the effect of the radionuclide half-life on PET/CT imaging with PSMA-targeting radioligands
| Autor: | Gerhard Glatting, Peter Kletting, Nusrat Jihan Begum, Ambros J. Beer, Matthias Eiber |
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| Rok vydání: | 2020 |
| Předmět: |
Glutamate Carboxypeptidase II
Radioisotopes Radionuclide Physiologically based pharmacokinetic modelling business.industry Ligand In silico Radiochemistry Half-life General Medicine Ligands urologic and male genital diseases Affinities Dissociation constant Pharmacokinetics Positron Emission Tomography Computed Tomography Antigens Surface Medicine Computer Simulation Radiology Nuclear Medicine and imaging business Half-Life |
| Zdroj: | Nuklearmedizin - NuclearMedicine. 60:33-37 |
| ISSN: | 2567-6407 0029-5566 |
| Popis: | Aim The aim of this work was to systematically investigate the influence of the radionuclide half-life and affinity of prostate-specific membrane antigen (PSMA)-targeting ligands on the activity concentration for PET/CT imaging. Methods A whole-body physiologically-based pharmacokinetic (PBPK) model with individually estimated parameters of 13 patients with metastatic castration-resistant prostate cancer (mCRPC) was used to simulate the pharmacokinetics of PSMA-targeting radioligands. The simulations were performed with 68Ga (T1/2 = 1.13 h), 18F (T1/2 = 1.83 h), 64Cu (T1/2 = 12.7 h) and for different affinities (dissociation constants KD of 1–0.01 nM) and a commonly used ligand amount of 3 nmol. The activity concentrations were calculated at 1, 2, 3, 4, 8, 12, and 16 h after injection. Results The highest tumor uptake was achieved 1 h p. i. for 68Ga-PSMA. For 18F-PSMA, the highest tumor uptake was at 1 h p. i. and 2 h p.i for dissociation constants KD = 1 nM and KD = 0.1–0.01 nM, respectively. For 64Cu-PSMA, the highest tumor uptake was at 4 h p. i. for dissociation constant KD = 1 nM and at 4 h p. i. (9 patients) and 8 h p. i. (4 patients) for higher affinities. Compared to 68Ga-PSMA (1 h p. i.), the activity concentrations in the tumor for 18F-PSMA (2 h p. i.) increased maximum 1.3-fold with minor differences for all affinities. For 64Cu-PSMA (4 h p. i.), the improvements were in the range of 2.8 to 3.2-fold for all affinities. Conclusions The simulations indicate that the highest tumor-to-background ratio can be achieved after 4 hours in PET/CT using high-affinity 64Cu-PSMA. |
| Databáze: | OpenAIRE |
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