Abstract
Purpose: In high-grade soft-tissue sarcomas (STS) the standard of care encompasses multimodal therapy regimens. While there is a growing body of evidence for prognostic pretreatment radiomic models, we hypothesized that temporal changes in radiomic features following neoadjuvant treatment ("delta-radio mics") may be able to predict the pathological complete response (pCR). Methods: MRI scans (T1-weighted with fat-saturation and contrast-enhancement (T1FSGd) and T2 weighted with fat-saturation (T2FS)) of patients with STS of the extremities and trunk treated with neoadjuvant therapy were gathered from two independent institutions (training: 103, external testing: 53 patients). pCR was defined as <5% viable cells. After segmentation and preprocessing, 105 radiomic features were extracted. Delta-radiomic features were calculated by subtraction of features derived from MRI scans obtained before and after neoadjuvant therapy. After feature reduction, machine learning modeling was performed in 100 iterations of 3-fold nested cross-validation. Delta-radiomic models were compared with single timepoint models in the testing cohort. Results: The combined delta-radiomic models achieved the best area under the receiver operating characteristic curve (AUC) of 0.75. Pre-therapeutic tumor volume was the best conventional predictor (AUC 0.70). The T2FS-based delta-radiomic model had the most balanced classification performance with a balanced accuracy of 0.69. Delta-radiomic models achieved better reproducibility than single timepoint radiomic models, RECIST or the peri-therapeutic volume change. Delta-radiomic models were significantly associated with survival in multivariate Cox regression. Conclusion: This exploratory analysis demonstrated that MRI-based delta-radiomics improves prediction of pCR over tumor volume and RECIST. Delta-radiomics may one day function as a biomarker for personalized treatment adaptations. (c) 2021 Elsevier B.V. All rights reserved. Radiotherapy and Oncology 164 (2021) 73-82
Original language | English |
---|---|
Pages (from-to) | 73-82 |
Number of pages | 10 |
Journal | Radiotherapy and Oncology |
Volume | 164 |
DOIs | |
Publication status | Published - 1 Nov 2021 |
Keywords
- Soft-tissue sarcoma
- Delta radiomics
- Neoadjuvant radiotherapy
- Machine learning
- Response prediction
- MRI
- EUROPEAN ORGANIZATION
- FEATURE-SELECTION
- CANCER
- CHEMOTHERAPY
- EXTREMITY
- SURVIVAL
- NECROSIS
- FEATURES
- MODEL