Association between textural and morphological tumor indices on baseline PET-CT and early metabolic response on interim PET-CT in bulky malignant lymphomas

Autor: Marilyne Kafrouni, Yassine Al Tabaa, Denis Mariano-Goulart, Fabien Vauchot, Guillaume Cartron, Fayçal Ben Bouallègue
Přispěvatelé: Service de médecine nucléaire [Montpellier], Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier), Physiologie & médecine expérimentale du Cœur et des Muscles [U 1046] (PhyMedExp), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), CHU Montpellier, Department of Clinical Hematology, Montpellier, France, Université de Montpellier (UM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)
Rok vydání: 2016
Předmět:
Zdroj: Medical Physics
Medical Physics, American Association of Physicists in Medicine, 2017, 44 (9), pp.4608-4619. ⟨10.1002/mp.12349⟩
ISSN: 2473-4209
0094-2405
DOI: 10.1002/mp.12349⟩
Popis: Purpose We investigated whether metabolic, textural and morphological tumoral indices evaluated on baseline PET-CT were predictive of early metabolic response on interim PET-CT in a cohort of patients with bulky Hodgkin and non-Hodgkin malignant lymphomas. Methods This retrospective study included 57 patients referred for initial PET-CT examination. In-house dedicated software was used to delineate tumor contours using a fixed 30% threshold of SUV max and then to compute tumoral metabolic parameters (SUV max, mean, peak, standard deviation, skewness and kurtosis, metabolic tumoral volume (MTV), total lesion glycolysis, and area under the curve of the cumulative histogram), textural parameters (Moran's and Geary's indices, energy, entropy, contrast, correlation derived from the gray-level co-occurrence matrix, area under the curve of the power spectral density, auto-correlation distance, and granularity), and shape parameters (surface, asphericity, convexity, surfacic extension, and 2D and 3D fractal dimensions). Early metabolic response was assessed on interim PET-CT using the Deauville 5-point scale and patients were ranked according to the Lugano classification as complete or not complete metabolic responders. The impact of the segmentation method (alternate threshold at 41%) and image resolution (Gaussian post-smoothing of 3, 5 and 7 mm) was investigated. The association of the proposed parameters with early response was assessed in univariate and multivariate analyses. Their added predictive value was explored using supervised classification by support vector machines (SVM). We evaluated in leave-one-out cross-validation three SVMs admitting as input vectors (1) MTV, (2) MTV + histological type, and (3) MTV + histology + relevant texture/shape indices. Results Features associated with complete metabolic response were low MTV (p=0.01), low TLG (p=0.003), high power spectral density AUC (p=0.007), high surfacic extension (p=0.006), low 2D fractal dimension (p=0.007), and low 3D fractal dimension (p=0.003). The prognostic value of these metrics was optimal with the 30% segmentation threshold and overall was progressively altered with decreasing image resolution. In cross-validation, the SVM accounting for texture and shape achieved the highest predictive value with ROC AUC of 0.82 and 80% accuracy (compared with 0.65 and 68% for MTV, and 0.68 and 61% for MTV + histology). Conclusions The combination of usual prognostic factors with appropriately chosen textural and shape parameters evaluated on baseline PET-CT improves the prediction of early metabolic response in bulky lymphoma. This article is protected by copyright. All rights reserved.
Databáze: OpenAIRE
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