Radiomics of portal-phase ring enhancement: a novel imaging biomarker for bevacizumab response associated with overall survival rates. It might help with surgical decision-making in colorectal liver metastases?

The liver is the most common site of metastases from colorectal cancer (CRC), affecting up to half of patients throughout their disease course. Although contrast-enhanced computed tomography (CECT) is routinely used for staging and treatment monitoring, RECIST criteria poorly reflect biological heterogeneity and antiangiogenic therapy effects. Integrating radiological and radiomic biomarkers may enhance response evaluation and personalized treatment. This study aimed to evaluate portal-phase ring enhancement as a potential imaging biomarker of disease progression and prognosis in patients with colorectal liver metastases (CRLM) treated with bevacizumab-based chemotherapy and to explore its correlation with CT-derived radiomic features. Eighty consecutive patients with histologically confirmed CRLM treated with standard chemotherapy plus bevacizumab were retrospectively analyzed. Baseline and 3-month CECT scans were evaluated for the presence and evolution of portal-phase ring enhancement. Radiomic features were extracted and correlated with morphologic patterns, while survival outcomes were assessed using Kaplan-Meier and logistic regression analyses. Baseline portal-phase ring enhancement was observed in 32.5% of patients and was significantly associated with inferior overall survival (p = 0.001), a finding confirmed on follow-up imaging (p = 0.016). Among radiomic features, sphericity showed the strongest correlation with ring enhancement (p = 0.003), yielding a modestly discriminative model. Portal-phase ring enhancement represents a reproducible imaging biomarker of poor prognosis in bevacizumab-treated CRLM. Its correlation with distinct radiomic signatures reinforces its biological plausibility as a marker of tumor aggressiveness. Integrating this feature with shape-based metrics into early imaging evaluation may refine risk stratification and personalized management.