Thrussell Imogen, Winfield Jessica M, Orton Matthew R, Miah Aisha B, Zaidi Shane H, Arthur Amani, Thway Khin, Strauss Dirk C, Collins David J, Koh Dow-Mu, Oelfke Uwe, Huang Paul H, O'Connor James P B, Messiou Christina, Blackledge Matthew D
Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, United Kingdom.
Department of Radiology, The Royal Marsden National Health Service (NHS) Foundation Trust, Sutton, United Kingdom.
Front Oncol. 2022 Jul 18;12:899180. doi: 10.3389/fonc.2022.899180. eCollection 2022.
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).
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.
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).
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.
基于大小的评估是软组织肉瘤（STS）肿瘤反应的不准确指标，这促使人们需要针对这种罕见且异质性疾病开发新的反应成像生物标志物。在本研究中，我们评估了腹膜后STS患者磁共振扩散加权成像（DWI）及其表观扩散系数（ADC）衍生图的放射组学特征的重测重复性，并将基线重复性与放疗（RT）后放射组学特征的变化进行比较。
30例腹膜后STS患者在治疗前接受了磁共振检查，其中23/30例在接受重复基线检查后纳入我们的重复性分析，14/30例患者在完成术前放疗后接受磁共振检查，纳入我们的治疗后分析。使用PyRadiomics从完全手动勾勒的肿瘤区域中提取107个放射组学特征。使用组内相关系数（基线ICC）评估重测重复性，并使用放疗后方差分析（RT后IMS）比较放射组学特征值相对于基线重复性的变化。
对于ADC图和DWI图像，分别有101个和102个特征显示出良好的基线重复性（基线ICC>0.85）。分别有43个和2个特征同时显示出良好的基线重复性和较高的RT后IMS（>0.85）。基线ICC与RT后IMS之间的Pearson相关性较弱（分别为0.432和0.133）。
与STS中从DWI图像得出的特征相比，基于ADC的放射组学分析显示出更好的重测重复性，其中一些特征对治疗后变化敏感。然而，基线时的良好重复性并不意味着对治疗后变化敏感。
