A <scp>gate</scp> evaluation of the sources of error in quantitative<sup>90</sup>Y PET

Strydhorst, Jared; Carlier, Thomas; Dieudonné, Arnaud; Conti, Maurizio; Buvat, Irène

doi:10.1118/1.4961747

Cited by 13 publications

(19 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Y-90 imaging involves SPECT via bremsstrahlung photons or PET via very low probability (~3.2 × 10 −5 ) positrons in the presence of increased singles events from bremsstrahlung photons and gammas from natural radioactivity in Lu-based crystals used in some PET systems. Due to these attributes of Y-90, positive bias in cold regions and underestimation in regions of interest are reported in many Y-90 PET papers (Carlier et al (2015), Pasciak et al (2014) and Strydhorst et al (2016)). Those reports conclude that the bias is introduced by the current standard PET reconstruction algorithms that enforce a nonnegativity constraint in the image domain.…”

Section: Introductionmentioning

confidence: 99%

A PET reconstruction formulation that enforces non-negativity in projection space for bias reduction in Y-90 imaging

2018

View full text Add to dashboard Cite

Most existing PET image reconstruction methods impose a nonnegativity constraint in the image domain that is natural physically, but can lead to biased reconstructions. This bias is particularly problematic for Y-90 PET because of the low probability positron production and high random coincidence fraction. This paper investigates a new PET reconstruction formulation that enforces nonnegativity of the projections instead of the voxel values. This formulation allows some negative voxel values, thereby potentially reducing bias. Unlike the previously reported NEG-ML approach that modifies the Poisson log-likelihood to allow negative values, the new formulation retains the classical Poisson statistical model. To relax the non-negativity constraint embedded in the standard methods for PET reconstruction, we used an alternating direction method of multipliers (ADMM). Because choice of ADMM parameters can greatly influence convergence rate, we applied an automatic parameter selection method to improve the convergence speed. We investigated the methods using lung to liver slices of XCAT phantom. We simulated low true coincidence count-rates with high random fractions corresponding to the typical values from patient imaging in Y-90 microsphere radioembolization. We compared our new methods with standard reconstruction algorithms and NEG-ML and a regularized version thereof. Both our new method and NEG-ML allow more accurate quantification in all volumes of interest while yielding lower noise than the standard method. The performance of NEG-ML can degrade when its user-defined parameter is tuned poorly, while the proposed algorithm is robust to any count level without requiring parameter tuning.

show abstract

Section: Introductionmentioning

confidence: 99%

A PET reconstruction formulation that enforces non-negativity in projection space for bias reduction in Y-90 imaging

2018

View full text Add to dashboard Cite

show abstract

“…The use of correct point spread function (PSF) modeling and TOF reconstruction kept background variability and noise at acceptable levels [ 98 ]. This was further corroborated in a fully Monte Carlo-based simulation in which 90 Y quantitation is compared to that of 18 F [ 99 ]. It was found that, relative to 18 F, the image quality was only slightly poorer in 90 Y for a similar positron emission rate.…”

Section: Reviewmentioning

confidence: 75%

The physics of radioembolization

et al. 2018

View full text Add to dashboard Cite

Radioembolization is an established treatment for chemoresistant and unresectable liver cancers. Currently, treatment planning is often based on semi-empirical methods, which yield acceptable toxicity profiles and have enabled the large-scale application in a palliative setting. However, recently, five large randomized controlled trials using resin microspheres failed to demonstrate a significant improvement in either progression-free survival or overall survival in both hepatocellular carcinoma and metastatic colorectal cancer. One reason for this might be that the activity prescription methods used in these studies are suboptimal for many patients.In this review, the current dosimetric methods and their caveats are evaluated. Furthermore, the current state-of-the-art of image-guided dosimetry and advanced radiobiological modeling is reviewed from a physics’ perspective. The current literature is explored for the observation of robust dose-response relationships followed by an overview of recent advancements in quantitative image reconstruction in relation to image-guided dosimetry.This review is concluded with a discussion on areas where further research is necessary in order to arrive at a personalized treatment method that provides optimal tumor control and is clinically feasible.

show abstract

“…They are summarised in Table 5. Some studies focused on qualitative and detection performances through image quality reports [34,52,54,55,57,[59][60][61], such as the CRC and the background variation (BV) following the NEMA NU-2 standards and guidelines [33]. Some other studies focused on a more quantitative evaluation on activity concentrations trough RC AC [22, 34, 36, 44, 48-51, 53, 56, 58, 59, 61].…”

Section: Discussionmentioning

confidence: 99%

“…Elschot et al [52] in 2013 showed through DVH that 90 Y dosimetry is more precise for PET than SPECT imaging. Strydhorst et al [55] in 2016 showed in their study that the bremsstrahlung radiation had negligible effects on PET-image image quality using Monte Carlo simulations. D'Arienzo et al [56] in 2017 concluded that the post-SIRT dosimetry is possible even in conditions of low statistics and high random fraction, granted that accurate PET calibration is performed and acquisition durations are sufficiently long.…”

Section: Discussionmentioning

confidence: 99%

Yttrium-90 Quantitative Phantom Study Using Digital Photon Counting PET

Labour

Boissard

Baudier

et al. 2021

Preprint

View full text Add to dashboard Cite

Background: PET imaging of 90Y-microspheres distribution following radioembolisation is a challenging task due to the count-starved statistics from the low branching ratio producing e+/e- pairs during 90Y decay. The recent PET systems using silicon photo-multipliers technology has shown better 90Y image quality compared to photo-multiplier tubes. The aim of the present study was to quantitatively evaluate the impact of 90Y imaging conditions and reconstruction parameters on the dosimetry calculations using a digital photon counting PET.Methods: Quantitative PET and dosimetry accuracy were evaluated using two uniform cylindrical phantoms specific for PET calibration validation. A body phantom with an 9:1 hot sphere-to-background ratio was scanned at different activity concentrations of 90Y. Reconstructions were performed using OSEM algorithm with varying parameters. Time-of-flight and point-spread function modellings were included in all reconstructions. Absorbed dose calculations were carried out using Voxel S-Values convolution and were compared to reference Monte Carlo simulations. Dose-volume histograms and root-mean-square deviations were used to evaluate reconstruction parameter sets. Thanks to listmode data, datasets for phantoms and patients were rebinned into varying lengths of time to assess the influence of acquisition duration on the calculation of absorbed dose. Results: A 2 mm full width at half maximum post-reconstruction Gaussian filter size can be used for image reconstruction, keeping the same accuracy as when no filter is applied for dosimetry purposes and reducing noise. Larger filter sizes should not be used. An acquisition duration of more than 10 min/bed reduces image noise but has no significant impact in the quantification of phantom and patient data for the digital photon counting PET. 3 iterations with 10 subsets was found suitable for large spheres whereas 1 iteration with 30 subsets could improve dosimetry for smaller spheres. Conclusion: The choice of iterations and subsets combination depends on the size of the spheres. However, one should be careful on this choice, depending on the imaging conditions and setup. This study can be useful in this choice for future studies for more accurate 90Y post-dosimetry using a digital photon counting PET.

show abstract

A gate evaluation of the sources of error in quantitative⁹⁰Y PET

Cited by 13 publications

References 35 publications

A PET reconstruction formulation that enforces non-negativity in projection space for bias reduction in Y-90 imaging

A PET reconstruction formulation that enforces non-negativity in projection space for bias reduction in Y-90 imaging

The physics of radioembolization

Yttrium-90 Quantitative Phantom Study Using Digital Photon Counting PET

Contact Info

Product

Resources

About

A gate evaluation of the sources of error in quantitative90Y PET

Cited by 13 publications

References 35 publications

A PET reconstruction formulation that enforces non-negativity in projection space for bias reduction in Y-90 imaging

A PET reconstruction formulation that enforces non-negativity in projection space for bias reduction in Y-90 imaging

The physics of radioembolization

Yttrium-90 Quantitative Phantom Study Using Digital Photon Counting PET

Contact Info

Product

Resources

About

A gate evaluation of the sources of error in quantitative⁹⁰Y PET