Reproducibility of lung cancer radiomics features extracted from data-driven respiratory gating and free-breathing flow imaging in [18F]-FDG PET/CT

Abstract

Background Quality and reproducibility of radiomics studies are essential requirements for the standardisation of radiomics models. As recent data-driven respiratory gating (DDG) [18F]-FDG has shown superior diagnostic performance in lung cancer, we evaluated the impact of DDG on the reproducibility of radiomics features derived from [18F]-FDG PET/CT in comparison to free-breathing flow (FB) imaging. Methods Twenty four lung nodules from 20 patients were delineated. Radiomics features were derived on FB flow PET/CT and on the corresponding DDG reconstruction using the QuantImage v2 platform. Lin’s concordance factor (Cb) and the mean difference percentage (DIFF%) were calculated for each radiomics feature using the delineated nodules which were also classified by anatomical localisation and volume. Non-reproducible radiomics features were defined as having a bias correction factor Cb < 0.8 and/or a mean difference percentage DIFF% > 10. Results In total 141 features were computed on each concordance analysis, 10 of which were non-reproducible on all pulmonary lesions. Those were first-order features from Laplacian of Gaussian (LoG)-filtered images (sigma = 1 mm): Energy, Kurtosis, Minimum, Range, Root Mean Squared, Skewness and Variance; Texture features from Gray Level Cooccurence Matrix (GLCM): Cluster Prominence and Difference Variance; First-order Standardised Uptake Value (SUV) feature: Kurtosis. Pulmonary lesions located in the superior lobes had only stable radiomics features, the ones from the lower parts had 25 non-reproducible radiomics features. Pulmonary lesions with a greater size (defined as long axis length > median) showed a higher reproducibility (9 non-reproducible features) than smaller ones (20 non-reproducible features). Conclusion Calculated on all pulmonary lesions, 131 out of 141 radiomics features can be used interchangeably between DDG and FB PET/CT acquisitions. Radiomics features derived from pulmonary lesions located inferior to the superior lobes are subject to greater variability as well as pulmonary lesions of smaller size.

Reproducibility of the principal component analysis (PCA)‐based data‐driven respiratory gating on texture features in non‑small cell lung cancer patients with 18F‑FDG PET/CT

“…13,31,34 The reproducibility rate of this study was as high as the SAM-based DDG-PET study that 131/141 (92.9%) image features had reproducibility. 30 The similar high reproducibility of PCAbased DDG-PET and SAM-based DDG-PET suggests the potential for interchangeability of texture features between other DDG-PET methods and NG-PET. In contrast, some texture features associated with GLRLM and GLZLM were not reproducible because these matrix indices, which are known to be highly variable, are calculated from large scales with many voxels.…”

“…[22][23][24]37,38 Although several studies have demonstrated the reproducibility or variability between non-gated PET and external respiratory-gated PET methods, there are few studies on the novel DDG-based respiratory gating. [27][28][29][30] To the best of our knowledge, this is the first study to evaluate the reproducibility of PCA-based DDG on texture features in patients with NSCLC. In this study, total of 39/46 (84.8%) image features demonstrated repeatability based on adequate strength of agreement and non-significant variability.…”

“…Each patient had a single intrapulmonary lesion that was selected per the 10−64-mm size criterion and the 2.5 > SUV criterion. 5,30 Our institutional ethics committee approved this study (No. 2021-GB-029).…”

“…28 On the contrary, Grootjans et al reported that respiratory gating did not result in statistically significant differences in textural parameters between non-gated PET and respiratory-gated PET in the whole cohort. 29 Faist et al evaluated the reproducibility of image features extracted from SAM-based DDG and reported that most radiomics features had high reproducibility 30 The interpretation of previous results requires further evaluation.…”

“…Faist et al. evaluated the reproducibility of image features extracted from SAM‐based DDG and reported that most radiomics features had high reproducibility 30 The interpretation of previous results requires further evaluation. Additionally, the reproducibility of PCA‐based DDG has not been evaluated.…”