We characterized the effect of systemic therapy given after portal vein embolization (PVE) and before hepatectomy on hepatic tumor and functional liver remnant (FLR) volumes. All 76 patients who underwent right PVE from 2002–2016 were retrospectively studied. Etiologies included colorectal cancer (n = 44), hepatocellular carcinoma (n = 17), cholangiocarcinoma (n = 10), and other metastases (n = 5). Imaging before and after PVE was assessed. Chart review revealed systemic therapy administration, SNaPshot genetic profiling, and comorbidities. Nine patients received systemic therapy; 67 did not. Tumor volume increased 28% in patients who did not receive and decreased −24% in patients who did receive systemic therapy (p = 0.026), with no difference in FLR growth (28% vs. 34%; p = 0.645). Among 30 patients with genetic profiling, 15 were wild type and 15 had mutations. Mutations were an independent predictor of tumor growth (p = 0.049), but did not impact FLR growth (32% vs. 28%; p = 0.93). Neither cirrhosis, hepatic steatosis, nor diabetes impacted changes in tumor or FLR volume (p > 0.20). Systemic therapy administered after PVE before hepatic lobectomy had no effect on FLR growth; however, it was associated with decreasing tumor volumes. Continuing systemic therapy until hepatectomy may be warranted, particularly in patients with genetic mutations.

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.