The Role of Perilesional Edema and Vascularity in Predicting Soft Tissue Metastases: Radiological Evaluation of 196
Abidin Emre Kılıç1, Nazan Çiledağ1, Burcu Savran1
1Department of Radiology, Dr. Abdurrahman Yurtaslan Ankara Oncology Training and Research Hospital, Ankara, Türkiye.
Introduction:
Soft tissue metastases are rare lesions seen in the course of systemic malignancies and pose diagnostic challenges. Radiological findings are heterogeneous, and standardized criteria are needed for reliable differentiation from benign lesions. While the diagnostic importance of perilesional changes is emphasized in the current literature, comprehensive analyses considering the clustered data structure are lacking. In this study, we aimed to determine effective radiological parameters for distinguishing soft tissue metastases from benign soft tissue lesions and to reveal the independent predictive value of perilesional findings.
Methods:
Soft tissue lesions detected by computed tomography (CT) and magnetic resonance imaging (MRI) between January 2015 and December 2023 were retrospectively evaluated in this single-center study. The study included 57 benign lesions (55 patients) and 139 metastatic lesions (65 patients). Lesion size, contour characteristics, morphological shape, anatomical localization, perilesional edema, and perilesional vascularity were evaluated. Due to the clustered data structure, the Generalized Estimating Equations (GEE) methodology was used. Model performance was evaluated using ROC curve analysis, precision-recall curve, and Brier score. Statistical analyses were performed using Jamovi v2.6.44, JASP v0.19.3, and R v4.5.1 software.
Results:
Metastatic lesions were significantly smaller than benign lesions (median 17.0 mm vs. 33.3 mm; p<0.001). In the GEE analysis, the presence of perilesional edema increased the likelihood of metastasis by 35 times (OR=35.25; 95% CI: 7.58-164.00; p<0.001), and perilesional vascularity increased the likelihood of metastasis by 45 times (OR=44.54; 95% CI: 1.86-1066.00; p = 0.016). Abdominal-pelvic localization showed a 133- fold (OR=133.00; 95% CI: 10.90-1622.00; p<0.001) higher likelihood of metastasis compared to the extremities, while thoracic-anterior chest wall localization showed a 35-fold (OR=35.22; 95% CI: 2.41-514.00; p = 0.007). Each unit increase in standardized size reduced the likelihood of metastasis by 90% (OR=0.10; 95% CI: 0.02-0.42; p = 0.001). The model demonstrated excellent discrimination (AUC-ROC=0.947) and calibration (Brier score=0.075) performance.
Discussion:
Our results show that perilesional edema and perilesional vascularity are key diagnostic signs of metastatic lesions. The combined assessment of perilesional findings and anatomical localization can significantly enhance diagnostic accuracy in daily practice. Furthermore, the relationship between lesion size and the metastatic process emphasizes the need for more careful evaluation of smaller lesions.
Conclusion:
Perilesional edema, perilesional vascularity, and trunk region localization were associated with soft tissue metastasis. These findings may be helpful in the radiological differentiation of metastasis and benign soft tissue lesions.
