Purpose: Bevacizumab added to chemotherapy can improve survival in patients with metastatic colorectal cancer, but no predictive factors of efficacy are available in clinical practice. The aim of this study is to assess the predictive and prognostic value of texture analysis on pretreatment contrast-enhanced CT in patients affected by colorectal liver metastases.
Materials and methods: Forty-three patients with colorectal liver metastases were retrospectively included in the study: 23 treated with bevacizumab-containing chemotherapy (group A), and 20 with standard chemotherapy (group B). Target liver lesions were analyzed by texture analysis of pretreatment contrast-enhanced CT. Texture analysis produced the parameter uniformity, describing lesion heterogeneity. Radiological response was classified after 3 months according to RECIST-1.1. Overall survival (OS) and progression-free survival (PFS) were considered to be outcome indicators. Multivariable logistic regression and survival analysis were performed.
Results: Uniformity was lower in responders than in nonresponders (p < 0.001) in group A but not in group B. Lesion CT density was lower in nonresponders in both groups (p = 0.03 and 0.02, respectively). In group A, uniformity was independently correlated with radiological response (odds ratio = 20, p = 0.01), OS and PFS (relative risks 6.94 and 5.05, respectively; p = 0.005 and p = 0.004, respectively). In group B, no variables were correlated with radiological response, OS or PFS.
Conclusion: Texture analysis on contrast-enhanced CT stratified response probability and prognosis in patients with colorectal liver metastases treated with bevacizumab-containing therapy. This result was specific for the bevacizumab group.
Keywords: Bevacizumab; Colorectal cancer; Contrast-enhanced computed tomography; Liver metastases; Texture analysis.