In vivo variability of MRI radiomics features in prostate lesions assessed by a test-retest study with repositioning.
Authors
Affiliations (13)
Affiliations (13)
- German Cancer Research Center (DKFZ), Division of Radiology, Heidelberg, Germany.
- German Cancer Research Center (DKFZ), Division of Biostatistics, Heidelberg, Germany.
- German Cancer Research Center (DKFZ), Division of Medical Image Computing, Heidelberg, Germany.
- Medical Faculty of Heidelberg University, Heidelberg, Germany.
- Department of Urology, Heidelberg University Hospital, Heidelberg, Germany.
- German Cancer Research Center (DKFZ), Junior Clinical Cooperation Unit 'Multiparametric Methods for Early Detection of Prostate Cancer, Heidelberg, Germany.
- Institute of Pathology, Heidelberg University Hospital, Heidelberg, Germany.
- National Center for Tumor Diseases (NCT) Heidelberg, Heidelberg, Germany.
- Pattern Analysis and Learning Group, Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany.
- German Cancer Research Center (DKFZ), Division of Radiology, Heidelberg, Germany. [email protected].
- Medical Faculty of Heidelberg University, Heidelberg, Germany. [email protected].
- National Center for Tumor Diseases (NCT) Heidelberg, Heidelberg, Germany. [email protected].
- Department of Radiology (E010), German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany. [email protected].
Abstract
Despite academic success, radiomics-based machine learning algorithms have not reached clinical practice, partially due to limited repeatability/reproducibility. To address this issue, this work aims to identify a stable subset of radiomics features in prostate MRI for radiomics modelling. A prospective study was conducted in 43 patients who received a clinical MRI examination and a research exam with repetition of T2-weighted and two different diffusion-weighted imaging (DWI) sequences with repositioning in between. Radiomics feature (RF) extraction was performed from MRI segmentations accounting for intra-rater and inter-rater effects, and three different image normalization methods were compared. Stability of RFs was assessed using the concordance correlation coefficient (CCC) for different comparisons: rater effects, inter-scan (before and after repositioning) and inter-sequence (between the two diffusion-weighted sequences) variability. In total, only 64 out of 321 (~ 20%) extracted features demonstrated stability, defined as CCC ≥ 0.75 in all settings (5 high-b value, 7 ADC- and 52 T2-derived features). For DWI, primarily intensity-based features proved stable with no shape feature passing the CCC threshold. T2-weighted images possessed the largest number of stable features with multiple shape (7), intensity-based (7) and texture features (28). Z-score normalization for high-b value images and muscle-normalization for T2-weighted images were identified as suitable.