Background: The accurate identification of the primary origin of malignant vertebral compression fractures and vertebral metastatic cancer (VMC) is critical for effective treatment, but current diagnostic approaches are invasive and lack specificity. We developed an explainable MRI-based radiomics model for tracing VMC origins noninvasively.
Materials and methods: This multicenter study included 1,123 patients with vertebral compression fractures from five hospitals with confirmed diagnoses; data from 754 patients in three centers were divided into training and validation cohorts based on the date of MRI examination. Two independent external test cohorts were used to evaluate the generalizability of the model. Sagittal T1 weighted images, T2 weighted images, and fat-suppression T2-weighted images were used for manual 3D lesion segmentation. In total, 3135 radiomic features were extracted from each region of interest. Feature selection was performed using the minimal redundancy maximal relevance algorithm. The final prediction model was established using a support vector machine algorithm.
Results: The radiomics model achieved areas under the receiver operating characteristic curves of 0.99, 0.87, and 0.88 in the validation, and two external test datasets, respectively, for VMC detection. For primary origin prediction, the model demonstrated high diagnostic accuracy across all datasets for lung, breast, and prostate origins. DeLong's test indicated a strong generalization capability of the model. SHAP analysis identified wavelet as key contributors to model transparency.
Conclusion: Our model was capable of distinguishing VMC from benign lesions and accurately predicting its primary origin. It demonstrated high generalizability and interpretability and represents a promising non-invasive tool to support clinical decision-making and reduce invasive biopsies.
Keywords: MRI; SHAP; machine learning; primary tumor origin; radiomics; vertebral metastatic cancer.
Copyright © 2025 The Author(s). Published by Wolters Kluwer Health, Inc.