Predicting the effect of different folate doses on [68Ga]Ga-PSMA-11 organ and tumor uptake using physiologically based pharmacokinetic modeling

EJNMMI Research

Original Research

Berlinda J. de Wit-van der Veen¹  Alwin D. R. Huitema²  Jeroen J. M. A. Hendrikx³  Hinke Siebinga³ 

[1] Department of Nuclear Medicine, The Netherlands Cancer Institute, Amsterdam, The Netherlands;Department of Pharmacy and Pharmacology, The Netherlands Cancer Institute, Amsterdam, The Netherlands;Department of Clinical Pharmacy, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands;Department of Pharmacology, Princess Máxima Center for Pediatric Oncology, Utrecht, The Netherlands;Department of Pharmacy and Pharmacology, The Netherlands Cancer Institute, Amsterdam, The Netherlands;Department of Nuclear Medicine, The Netherlands Cancer Institute, Amsterdam, The Netherlands;

关键词: [Ga]Ga-PSMA-11;    Folate;    Folic acid;    PSMA;    PBPK model;   

DOI  :  10.1186/s13550-023-01008-y

 received in 2023-04-18, accepted in 2023-05-26,  发布年份 2023

来源: Springer

【 摘 要 】

BackgroundFolate intake might reduce [68Ga]Ga-PSMA-11 uptake in tissues due to a competitive binding to the PSMA receptor. For diagnostic imaging, this could impact decision making, while during radioligand therapy this could affect treatment efficacy. The relationship between folate dose, timing of dosing and tumor and organ uptake is not well established. The aim of this study was to develop a physiologically based pharmacokinetic (PBPK) model to predict the effect of folates on [68Ga]Ga-PSMA-11 PET/CT uptake in salivary glands, kidneys and tumors.MethodsA PBPK model was developed for [68Ga]Ga-PSMA-11 and folates (folic acid and its metabolite 5-MTHF), with compartments added that represent salivary glands and tumor. Reactions describing receptor binding, internalization and intracellular degradation were included. Model evaluation for [68Ga]Ga-PSMA-11 was performed by using patient scan data from two different studies (static and dynamic), while for folates data from the literature were used for evaluation. Simulations were performed to assess the effect of different folate doses (150 µg, 400 µg, 5 mg and 10 mg) on accumulation in salivary glands, kidney and tumor, also for patients with different tumor volumes (10, 100, 500 and 1000 mL).ResultsFinal model evaluation showed that predictions adequately described data for both [68Ga]Ga-PSMA-11 and folates. Predictions of a 5-MTFH dose of 150 µg and folic acid dose of 400 µg (in case of administration at the same time as [68Ga]Ga-PSMA-11 (t = 0)) showed no clinically relevant effect on salivary glands and kidney uptake. However, the effect of a decrease in salivary glands and kidney uptake was determined to be clinically relevant for doses of 5 mg (34% decrease for salivary glands and 32% decrease for kidney) and 10 mg (36% decrease for salivary glands and 34% decrease for kidney). Predictions showed that tumor uptake was not relevantly affected by the co-administration of folate for all different folate doses (range 150 µg–10 mg). Lastly, different tumor volumes did not impact the folate effect on [68Ga]Ga-PSMA-11 biodistribution.ConclusionUsing a PBPK model approach, high doses of folate (5 and 10 mg) were predicted to show a decrease of [68Ga]Ga-PSMA-11 salivary glands and kidney uptake, while intake by means of folate containing food or vitamin supplements showed no relevant effects. In addition, tumor uptake was not affected by folate administration in the simulated dose ranges (150 µg–10 mg). Differences in tumor volume are not expected to impact folate effects on [68Ga]Ga-PSMA-11 organ uptake.

【 授权许可】

CC BY   
© The Author(s) 2023

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