Dataset Information

Improved image reconstruction of ⁸⁹Zr-immunoPET studies using a Bayesian penalized likelihood reconstruction algorithm.

ABSTRACT:

Purpose

The aim of this study was to evaluate the use of a Bayesian penalized likelihood reconstruction algorithm (Q.Clear) for ⁸⁹Zr-immunoPET image reconstruction and its potential to improve image quality and reduce the administered activity of ⁸⁹Zr-immunoPET tracers.

Methods

Eight ⁸⁹Zr-immunoPET whole-body PET/CT scans from three ⁸⁹Zr-immunoPET clinical trials were selected for analysis. On average, patients were imaged 6.3?days (range 5.0-8.0?days) after administration of 69?MBq (range 65-76?MBq) of [⁸⁹Zr]Zr-DFO-daratumumab, [⁸⁹Zr]Zr-DFO-pertuzumab, or [⁸⁹Zr]Zr-DFO-trastuzumab. List-mode PET data was retrospectively reconstructed using Q.Clear with incremental ?-values from 150 to 7200, as well as standard ordered-subset expectation maximization (OSEM) reconstruction (2-iterations, 16-subsets, a 6.4-mm Gaussian transaxial filter, "heavy" z-axis filtering and all manufacturers' corrections active). Reduced activities were simulated by discarding 50% and 75% of original counts in each list mode stream. All reconstructed PET images were scored for image quality and lesion detectability using a 5-point scale. SUV_max for normal liver and sites of disease and liver signal-to-noise ratio were measured.

Results

Q.Clear reconstructions with ? = 3600 provided the highest scores for image quality. Images reconstructed with ?-values of 3600 or 5200 using only 50% or 25% of the original counts provided comparable or better image quality scores than standard OSEM reconstruction images using 100% of counts.

Conclusion

The Bayesian penalized likelihood reconstruction algorithm Q.Clear improved the quality of ⁸⁹Zr-immunoPET images. This could be used in future studies to improve image quality and/or decrease the administered activity of ⁸⁹Zr-immunoPET tracers.

SUBMITTER: Kirchner J

PROVIDER: S-EPMC7815860 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature

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Publications

Improved image reconstruction of <sup>89</sup>Zr-immunoPET studies using a Bayesian penalized likelihood reconstruction algorithm.

Kirchner Julian J O'Donoghue Joseph A JA Becker Anton S AS Ulaner Gary A GA

EJNMMI physics 20210119 1

<h4>Purpose</h4>The aim of this study was to evaluate the use of a Bayesian penalized likelihood reconstruction algorithm (Q.Clear) for <sup>89</sup>Zr-immunoPET image reconstruction and its potential to improve image quality and reduce the administered activity of <sup>89</sup>Zr-immunoPET tracers.<h4>Methods</h4>Eight <sup>89</sup>Zr-immunoPET whole-body PET/CT scans from three <sup>89</sup>Zr-immunoPET clinical trials were selected for analysis. On average, patients were imaged 6.3 days (rang ...[more]

PMID: 33469848

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Project description:PurposeTargeted delivery in vivo remains an immense roadblock for the translation of nanomaterials into the clinic. The greatest obstacle is the mononuclear phagocyte system (MPS), which sequesters foreign substances from general circulation and causes accumulation in organs such as the liver and spleen. The purpose of this study was to determine whether attaching an active targeting antibody, 5B1, to the surface of gold nanoparticles and using clodronate liposomes to deplete liver and splenic macrophages could help to minimize uptake by MPS organs, increase targeted delivery to CA19.9-positive pancreatic tumors, and enhance pancreatic tumor delineation.ProceduresTo produce the antibody-gold nanoparticle conjugate (Ab-AuNP), the Ab was conjugated to p-isothiocyanatobenzyl-desferrioxamine (p-SCN-DFO) and subsequently conjugated to NHS-activated gold nanoparticles. The Ab-AuNP was characterized by transmission electron microscopy (TEM) and atomic force microscopy (AFM). Modified Lindmo assay was performed to assess binding affinity and internalization potential in vitro. The Ab-AuNP was radiolabeled with 89Zr and injected into CA19.9-positive BxPc-3 pancreatic orthotopic tumor-bearing mice pretreated with or without clodronate liposomes for PET imaging and biodistribution studies. Inductively coupled plasma-optical emission spectrometry (ICP-OES) analysis was used to confirm delivery of gold nanoparticles to BxPc-3 pancreatic subcutaneous xenografts.ResultsMice pretreated with clodronate liposomes in an orthotopic setting demonstrated decreased liver uptake at early time points (12.2 ± 2.3 % ID/g vs. 22.8 ± 3.8 % ID/g at 24 h) and increased tumor uptake at 120 h (13.8 ± 8.0 % ID/g vs. 6.0 ± 1.2 % ID/g). This allowed for delineation of orthotopic pancreatic xenografts in significantly more mice treated with clodronate (6/6) than in mice not treated with clodronate (2/6) or mice injected with gold nanoparticles labeled with a nonspecific antibody (0/5).ConclusionsThe combination of clodronate liposomes and an active targeting antibody on the surface of gold nanoparticles allowed for PET/CT imaging of subcutaneous and orthotopic pancreatic xenografts in mice.

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Dataset Information

Improved image reconstruction of ⁸⁹Zr-immunoPET studies using a Bayesian penalized likelihood reconstruction algorithm.

Purpose

Methods

Results

Conclusion

Publications

Improved image reconstruction of <sup>89</sup>Zr-immunoPET studies using a Bayesian penalized likelihood reconstruction algorithm.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Dataset Information

Improved image reconstruction of 89Zr-immunoPET studies using a Bayesian penalized likelihood reconstruction algorithm.

Purpose

Methods

Results

Conclusion

Publications

Improved image reconstruction of <sup>89</sup>Zr-immunoPET studies using a Bayesian penalized likelihood reconstruction algorithm.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Improved image reconstruction of ⁸⁹Zr-immunoPET studies using a Bayesian penalized likelihood reconstruction algorithm.