Radiomic Features From Diffusion-Weighted MRI of Retroperitoneal Soft-Tissue Sarcomas Are Repeatable and Exhibit Change After Radiotherapy

Imogen Thrussell; Jessica M Winfield; Matthew R Orton; Aisha B Miah; Shane H Zaidi; Amani Arthur; Khin Thway; Dirk C Strauss; David J Collins; Dow-Mu Koh; Uwe Oelfke; Paul H Huang; James P B O'Connor; Christina Messiou; Matthew D Blackledge

doi:10.3389/fonc.2022.899180

Radiomic Features From Diffusion-Weighted MRI of Retroperitoneal Soft-Tissue Sarcomas Are Repeatable and Exhibit Change After Radiotherapy

Front Oncol. 2022 Jul 18:12:899180. doi: 10.3389/fonc.2022.899180. eCollection 2022.

Authors

Imogen Thrussell^{1

2}, Jessica M Winfield^{1

2}, Matthew R Orton^{1

2}, Aisha B Miah^{1

3}, Shane H Zaidi^{1

3}, Amani Arthur^{1

2}, Khin Thway^{3

4}, Dirk C Strauss⁵, David J Collins^{1

2}, Dow-Mu Koh^{1

2}, Uwe Oelfke¹, Paul H Huang⁶, James P B O'Connor^{1

7

8}, Christina Messiou^{1

2}, Matthew D Blackledge^{1

2}

Affiliations

¹ Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, United Kingdom.
² Department of Radiology, The Royal Marsden National Health Service (NHS) Foundation Trust, Sutton, United Kingdom.
³ Sarcoma Unit, The Royal Marsden National Health Service (NHS) Foundation Trust, London, United Kingdom.
⁴ Department of Histopathology, The Royal Marsden National Health Service (NHS) Foundation Trust, London, United Kingdom.
⁵ Department of Surgery, The Royal Marsden National Health Service (NHS) Foundation Trust, London, United Kingdom.
⁶ Division of Molecular Pathology, The Institute of Cancer Research, London, United Kingdom.
⁷ Division of Cancer Sciences, University of Manchester, Manchester, United Kingdom.
⁸ Department of Radiology, The Christie Hospital, Manchester, United Kingdom.

Abstract

Background: Size-based assessments are inaccurate indicators of tumor response in soft-tissue sarcoma (STS), motivating the requirement for new response imaging biomarkers for this rare and heterogeneous disease. In this study, we assess the test-retest repeatability of radiomic features from MR diffusion-weighted imaging (DWI) and derived maps of apparent diffusion coefficient (ADC) in retroperitoneal STS and compare baseline repeatability with changes in radiomic features following radiotherapy (RT).

Materials and methods: Thirty patients with retroperitoneal STS received an MR examination prior to treatment, of whom 23/30 were investigated in our repeatability analysis having received repeat baseline examinations and 14/30 patients were investigated in our post-treatment analysis having received an MR examination after completing pre-operative RT. One hundred and seven radiomic features were extracted from the full manually delineated tumor region using PyRadiomics. Test-retest repeatability was assessed using an intraclass correlation coefficient (baseline ICC), and post-radiotherapy variance analysis (post-RT-IMS) was used to compare the change in radiomic feature value to baseline repeatability.

Results: For the ADC maps and DWI images, 101 and 102 features demonstrated good baseline repeatability (baseline ICC > 0.85), respectively. Forty-three and 2 features demonstrated both good baseline repeatability and a high post-RT-IMS (>0.85), respectively. Pearson correlation between the baseline ICC and post-RT-IMS was weak (0.432 and 0.133, respectively).

Conclusions: The ADC-based radiomic analysis shows better test-retest repeatability compared with features derived from DWI images in STS, and some of these features are sensitive to post-treatment change. However, good repeatability at baseline does not imply sensitivity to post-treatment change.

Keywords: DWI (diffusion weighted imaging); Intraclass correlation coefficient (ICC); apparent diffusion coefficient (ADC); radiomics; radiotherapy; repeatability; soft-tissue sarcoma.

Abstract

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