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A Physiologically Based Pharmacokinetic (PBPK) Model to Describe Organ Distribution of Ga-DOTATATE in Patients Without Neuroendocrine Tumors

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Journal EJNMMI Res
Date 2021 Aug 16
PMID 34398356
Citations 7
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Abstract

Background: Physiologically based pharmacokinetic (PBPK) models combine drug-specific information with prior knowledge on the physiology and biology at the organism level. Whole-body PBPK models contain an explicit representation of the organs and tissue and are a tool to predict pharmacokinetic behavior of drugs. The aim of this study was to develop a PBPK model to describe organ distribution of Ga-DOTATATE in a population of patients without detectable neuroendocrine tumors (NETs).

Methods: Clinical Ga-DOTATATE PET/CT data from 41 patients without any detectable somatostatin receptor (SSTR) overexpressing tumors were included. Scans were performed at 45 min (range 30-60 min) after intravenous bolus injection of Ga-DOTATATE. Organ (spleen, liver, thyroid) and blood activity levels were derived from PET scans, and corresponding DOTATATE concentrations were calculated. A whole-body PBPK model was developed, including an internalization reaction, receptor recycling, enzymatic reaction for intracellular degradation and renal clearance. SSTR2 expression was added for several organs. Input parameters were fixed or estimated using a built-in Monte Carlo algorithm for parameter identification.

Results: Ga-DOTATATE was administered with a median peptide amount of 12.3 µg (range 8.05-16.9 µg) labeled with 92.7 MBq (range 43.4-129.9 MBq). SSTR2 amounts for spleen, liver and thyroid were estimated at 4.40, 7.80 and 0.0108 nmol, respectively. Variability in observed organ concentrations was best described by variability in SSTR2 expression and differences in administered peptide amounts.

Conclusions: To conclude, biodistribution of Ga-DOTATATE was described with a whole-body PBPK model, where tissue distribution was mainly determined by variability in SSTR2 organ expression and differences in administered peptide amounts.

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References
1.
Reubi J, Schar J, Waser B, Wenger S, Heppeler A, Schmitt J . Affinity profiles for human somatostatin receptor subtypes SST1-SST5 of somatostatin radiotracers selected for scintigraphic and radiotherapeutic use. Eur J Nucl Med. 2000; 27(3):273-82. DOI: 10.1007/s002590050034. View

2.
Sabet A, Nagarajah J, Dogan A, Biersack H, Sabet A, Guhlke S . Does PRRT with standard activities of 177Lu-octreotate really achieve relevant somatostatin receptor saturation in target tumor lesions?: insights from intra-therapeutic receptor imaging in patients with metastatic gastroenteropancreatic.... EJNMMI Res. 2013; 3(1):82. PMC: 3877953. DOI: 10.1186/2191-219X-3-82. View

3.
Gospavic R, Knoll P, Mirzaei S, Popov V . Physiologically Based Pharmacokinetic (PBPK) Model for Biodistribution of Radiolabeled Peptides in Patients with Neuroendocrine Tumours. Asia Ocean J Nucl Med Biol. 2016; 4(2):90-7. PMC: 4938879. DOI: 10.7508/aojnmb.2016.02.005. View

4.
Sandstrom M, Velikyan I, Garske-Roman U, Sorensen J, Eriksson B, Granberg D . Comparative biodistribution and radiation dosimetry of 68Ga-DOTATOC and 68Ga-DOTATATE in patients with neuroendocrine tumors. J Nucl Med. 2013; 54(10):1755-9. DOI: 10.2967/jnumed.113.120600. View

5.
Hardiansyah D, Attarwala A, Kletting P, Mottaghy F, Glatting G . Prediction of time-integrated activity coefficients in PRRT using simulated dynamic PET and a pharmacokinetic model. Phys Med. 2017; 42:298-304. DOI: 10.1016/j.ejmp.2017.06.024. View