Comparison of quantitative whole body PET parameters on [68Ga]Ga-PSMA-11 PET/CT using ordered Subset Expectation Maximization (OSEM) vs. bayesian penalized likelihood (BPL) reconstruction algorithms in men with metastatic castration-resistant prostate cancer

Ayati, N; McIntosh, L; Buteau, J; Alipour, R; Pudis, M; Daw, N; Jackson, P; Hofman, MS

Author(s): Ayati, N; McIntosh, L; Buteau, J; Alipour, R; Pudis, M; Daw, N; Jackson, P; Hofman, MS;
Details: Publication Year 2024-05-06,Volume 24,Issue #1,Page 57
Journal Title: Cancer Imaging
Publication Type: Research article
Abstract: BACKGROUND: PSMA PET/CT is a predictive and prognostic biomarker for determining response to [(177)Lu]Lu-PSMA-617 in patients with metastatic castration resistant prostate cancer (mCRPC). Thresholds defined to date may not be generalizable to newer image reconstruction algorithms. Bayesian penalized likelihood (BPL) reconstruction algorithm is a novel reconstruction algorithm that may improve contrast whilst preventing introduction of image noise. The aim of this study is to compare the quantitative parameters obtained using BPL and the Ordered Subset Expectation Maximization (OSEM) reconstruction algorithms. METHODS: Fifty consecutive patients with mCRPC who underwent [(68)Ga]Ga-PSMA-11 PET/CT using OSEM reconstruction to assess suitability for [(177)Lu]Lu-PSMA-617 therapy were selected. BPL algorithm was then used retrospectively to reconstruct the same PET raw data. Quantitative and volumetric measurements such as tumour standardised uptake value (SUV)max, SUVmean and Molecular Tumour Volume (MTV-PSMA) were calculated on both reconstruction methods. Results were compared (Bland-Altman, Pearson correlation coefficient) including subgroups with low and high-volume disease burdens (MTV-PSMA cut-off 40 mL). RESULTS: The SUVmax and SUVmean were higher, and MTV-PSMA was lower in the BPL reconstructed images compared to the OSEM group, with a mean difference of 8.4 (17.5%), 0.7 (8.2%) and - 21.5 mL (-3.4%), respectively. There was a strong correlation between the calculated SUVmax, SUVmean, and MTV-PSMA values in the OSEM and BPL reconstructed images (Pearson r values of 0.98, 0.99, and 1.0, respectively). No patients were reclassified from low to high volume disease or vice versa when switching from OSEM to BPL reconstruction. CONCLUSIONS: [(68)Ga]Ga-PSMA-11 PET/CT quantitative and volumetric parameters produced by BPL and OSEM reconstruction methods are strongly correlated. Differences are proportional and small for SUVmean, which is used as a predictive biomarker. Our study suggests that both reconstruction methods are acceptable without clinical impact on quantitative or volumetric findings. For longitudinal comparison, committing to the same reconstruction method would be preferred to ensure consistency.
Publisher: BioMed Central
Keywords: Humans; Male; *Positron Emission Tomography Computed Tomography/methods; *Prostatic Neoplasms, Castration-Resistant/diagnostic imaging/pathology; *Gallium Radioisotopes; *Gallium Isotopes; *Bayes Theorem; Aged; Middle Aged; Retrospective Studies; *Algorithms; Oligopeptides; Edetic Acid/analogs & derivatives; Whole Body Imaging/methods; Radiopharmaceuticals; Aged, 80 and over; Neoplasm Metastasis; Image Processing, Computer-Assisted/methods; Dipeptides/therapeutic use; Bayesian penalized likelihood (BPL); Image reconstruction; Metastatic castration-resistant prostate cancer (mCRPC); Ordered subset expectation maximization (OSEM); Psma pet/ct
Department(s): Cancer Imaging; Physical Sciences
Publisher's Version: https://doi.org/10.1186/s40644-024-00702-x
Open Access at Publisher's Site: https://doi.org/10.1186/s40644-024-00702-x
Terms of Use/Rights Notice: Refer to copyright notice on published article.

Creation Date: 2024-06-25 07:58:46

Last Modified: 2024-06-25 08:02:37