Quality control of [177Lu]Lu-PSMA preparations using HPLC: effect of sample composition and ligand on recovery

• Published in: EJNMMI radiopharmacy and chemistry Vol. 7; no. 1; p. 24
• Main Authors: Aalbersberg, Else A., Cao, Tammie T., Geluk-Jonker, Martine M., Hendrikx, Jeroen J. M. A.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 27.09.2022; Springer Nature B.V; SpringerOpen
• Subjects: [177Lu]Lu-PSMA-617; [177Lu]Lu-PSMA-I&T; Area; Cancer therapies; Castration; Column interaction; Composition; Control methods; Dilution; High-performance liquid chromatography; HPLC; Imaging; Ligands; Liquid chromatography; Lutetium isotopes; Medical prognosis; Medicine; Medicine & Public Health; Metastases; Metastasis; Molecular Medicine; Nuclear Chemistry; Nuclear Medicine; Octreotide; Pharmacotherapy; Prostate cancer; PSMA; Quality control; Radioactivity; Radiology; Recovery; Research Article; Variability; Column interaction; PSMA; Lu]Lu-PSMA-I&T; [; HPLC; Lu]Lu-PSMA-617
• ISSN: 2365-421X; 2365-421X
• DOI: 10.1186/s41181-022-00178-9

Background [ 177 Lu]Lu-PSMA is used for the treatment of metastatic castration-resistant prostate cancer. For in-house productions, quality control methods are essential for ensuring product quality, and thus patient safety. During HPLC method development for quality control of [ 177 Lu]Lu-PSMA-I&T, we noticed an unpredictable variability in peak area and height with replicate measurements. After a run, irremovable radioactivity was measured over the whole the length of the HPLC column, with slightly higher activity at the beginning and end of the column. The uniform distribution suggests that [ 177 Lu]Lu-PSMA-I&T interacts with the column. As a result of the interaction, incomplete and variable recovery of injected activity was observed leading to the variability in peak area and height. Therefore the aim of this study was to (1) investigate the effect of sample composition on the interaction of [ 177 Lu]Lu-PSMA-I&T to the HPLC column (measured as recovery, peak area, and peak height), and (2) to compare this with same concentrations of the well-known [ 177 Lu]Lu-PSMA-617. Results Sample composition significantly affects recovery of [ 177 Lu]Lu-PSMA-I&T, leading to a change in peak area and height. Recovery was 24% when diluted with 0.1 mM octreotide, 38% with water, and increased to 95% when diluted with 0.7 mM unlabeled PSMA-I&T. Peak area and height decreased to 26% and 17% when diluted in octreotide and to 41% and 29% when diluted in water, compared to a dilution in PSMA-I&T. Further experiments showed that recovery (and consequently peak area and peak height) reached a plateau of > 99% at concentrations of 0.27 mM and higher. [ 177 Lu]Lu-PSMA-617 also interacts with the HPLC column, leading to lower, but less variable, recovery (9%). The low recovery of [ 177 Lu]Lu-PSMA-617 could not be prevented with addition of unlabeled PSMA-617. Conclusion [ 177 Lu]Lu-PSMA-I&T can undergo an irreversible binding with an HPLC column resulting in a decreased recovery. The recovery is can be highly dependent on sample composition. The addition of a surplus of unlabeled PSMA-I&T leads to an accurate analysis of [ 177 Lu]Lu-PSMA-I&T.