Quantifying Tumor Heterogeneity from Multiparametric Magnetic Resonance Imaging of Prostate Using Texture Analysis
by
, ,
Saleh T. Alanezi
1,2,*
,
Frank Sullivan
3,4,
Christoph Kleefeld
2,
John F. Greally
5,
Marcin J. Kraśny
2,
Peter Woulfe
6,
Declan Sheppard
6,7,† and
Niall Colgan
2,† 1
Physics Department, Faculty of Science, Northern Border University, Arar 1321, Saudi Arabia
2
School of Physics, College of Science and Engineering, National University of Ireland Galway, H91 CF50 Galway, Ireland
3
Prostate Cancer Institute, Department of Radiation Oncology, Galway Clinic, H91 HHT0 Galway, Ireland
4
School of Medicine, College of Medicine, Nursing, National University of Ireland Galway, H91 TK33 Galway, Ireland
5
Department of Pathology, Galway Clinic, H91 HHT0 Galway, Ireland
6
Department of Radiology, Galway Clinic, H91 HHT0 Galway, Ireland
7
Department of Radiology, University Hospital Galway, H91 YR71 Galway, Ireland
*
Author to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Cancers 2022, 14(7), 1631; https://doi.org/10.3390/cancers14071631
Submission received: 10 March 2022
/
Accepted: 16 March 2022
/
Published: 23 March 2022
(This article belongs to the Collection Advances in Diagnostic and Interventional Radiology in Oncology)
Simple Summary
Prostate cancer (PCa) occurs in males at a rate of 21.8%, predominantly at the customary primary site. High cure rates are possible through early detection and therapy when the tumor is still restricted to the prostate. These tumors do not grow rapidly, allowing for periods of up to 20 years between diagnosis and death. Multiparametric MRI (mp-MRI) is used as a non-invasive approach to diagnose PCa in subjects. This imaging method uses MR imaging with at least one functional MRI sequence to detect and characterize PCa. The use of multiparametric magnetic resonance imaging has refined the diagnosis of prostate cancer in radiology. Malignancy-modified critical features in tissue composition, such as heterogeneity, are associated with adverse tumor biology. Heterogeneity can be quantified through texture analysis, an effective technique for reviewing tumor images acquired in routine clinical practice. This study focused on identifying and quantifying tumor heterogeneity from prostate mp-MRI utilizing texture analysis.
Abstract
(1) Background: Multiparametric MRI (mp-MRI) is used to manage patients with PCa. Tumor identification via irregular sampling or biopsy is problematic and does not allow the comprehensive detection of the phenotypic and genetic alterations in a tumor. A non-invasive technique to clinically assess tumor heterogeneity is also in demand. We aimed to identify tumor heterogeneity from multiparametric magnetic resonance images using texture analysis (TA). (2) Methods: Eighteen patients with prostate cancer underwent mp-MRI scans before prostatectomy. A single radiologist matched the histopathology report to single axial slices that best depicted tumor and non-tumor regions to generate regions of interest (ROIs). First-order statistics based on the histogram analysis, including skewness, kurtosis, and entropy, were used to quantify tumor heterogeneity. We compared non-tumor regions with significant tumors, employing the two-tailed Mann–Whitney U test. Analysis of the area under the receiver operating characteristic curve (ROC-AUC) was used to determine diagnostic accuracy. (3) Results: ADC skewness for a 6 × 6 px filter was significantly lower with an ROC-AUC of 0.82 (p = 0.001). The skewness of the ADC for a 9 × 9 px filter had the second-highest result, with an ROC-AUC of 0.66; however, this was not statistically significant (p = 0.08). Furthermore, there were no substantial distinctions between pixel filter size groups from the histogram analysis, including entropy and kurtosis. (4) Conclusions: For all filter sizes, there was poor performance in terms of entropy and kurtosis histogram analyses for cancer diagnosis. Significant prostate cancer may be distinguished using a textural feature derived from ADC skewness with a 6 × 6 px filter size.
