Prognostic value of tumor asphericity and 18F-FDG PET/CT texture features in colorectal cancer

Aim The aim of this study was to investigate the prognostic value of tumor asphericity and radiomic features derived from 18F-FDG PET/CT in patients with colorectal cancer, and to evaluate their role in risk stratification for progression-free survival (PFS). Methods A retrospective analysis of 102 patients with diagnosed colorectal cancer who underwent pre-treatment 18F-FDG PET/CT imaging. Clinical variables, conventional PET parameters (SUVmax, MTV, TLG), Radiomic features, including tumor asphericity (ASP), GLCM (gray-level co-occurrence matrix)-entropy, GLSZM (gray-level size zone matrix), and GLRLM (gray-level run length matrix)-based parameters were extracted. PFS was the primary endpoint, and overall survival (OS) was the secondary endpoint. Univariate and multivariate Cox regression analyses, ROC curve analysis, and Kaplan–Meier curves were performed. Results Over a median of 26.5 months of follow-up, 59 patients (57.8%) had disease progression and 50 (49%) died. Progression correlated with higher ASP (<em>P</em> = .024), GLCM entropy (<em>P</em> < .001), GLSZM-SZE (<em>P</em> = .001), and lower GLSZM-LZE (<em>P</em> = .030). Univariate Cox analysis showed that ASP, GLCM entropy, GLSZM-SZE, GLSZM-LZE, and TNM stage were associated with PFS and OS. Multivariate analysis found ASP (HR=5.6, <em>P</em> = .021), GLCM entropy (HR=1.55, <em>P</em> = .006), and TNM stage (all <em>P</em> < .001) as independent factors. Higher than ROC cutoffs: 0.36 for ASP and 9.65 for GLCM entropy linked to shorter PFS (9.2 vs. 37.4 months, <em>P</em> < .001) and (21.6 vs. 52.3 months, <em>P</em> = .001), respectively. Conclusions Tumor asphericity and GLCM-derived entropy obtained from pretreatment 18F-FDG PET/CT provide independent and complementary prognostic information beyond conventional metabolic parameters in colorectal cancer. These biomarkers may improve risk stratification and identification of patients at increased risk of disease progression and mortality.