Dual-energy CT for predicting progression-free survival of locally advanced gastric cancer after gastrectomy: Insights into tumor angiogenesis.

Objectives: To investigate preoperative dual-energy CT (DECT)-derived independent risk factors affecting progression-free survival (PFS) in patients with locally advanced gastric cancer (LAGC) undergoing gastrectomy, and to reveal the underlying histopathologic changes.

Methods: This prospective study included patients who underwent preoperative DECT scan and gastrectomy. Clinical data, DECT-derived morphological characteristics and iodine-related parameters were comprehensively collected. Univariate and multivariate analyses were carried out to identify independent risk factors associated with PFS. The prognostic performance of various parameters was evaluated using the bootstrap-based consistency index (C-index) and time-dependent receiver operating characteristic (ROC) analysis. Kaplan-Meier curves were used to assess the differences in survival analysis. The histopathologic underpinnings of the DECT-based combined parameter for evaluating PFS were explored.

Results: 120 LAGC patients (63.3 ± 10.9 years; 94 men) were analyzed. Age, arterial enhancement fraction (AEF), serosal invasion, and tumor thickness were identified as preoperative independent risk factors affecting PFS (all p < 0.05). The combined parameters based on these risk factors achieved a C-index of 0.75, significantly or slightly superior to that of any single risk factor (all p < 0.05) or postoperative pathological staging (C-index, 0.67; p > 0.05). For predicting the 0.5-, 1- and 2-year PFS, the combined parameter had an area-under-the-curve (AUC) of 0.72, 0.77, and 0.74, respectively. PFS significantly differed between patients of high- and low-risks assessed with the combined parameter (p < 0.001). Histopathologically, the combined parameter was associated with tumor microvessel density (r = 0.31, p < 0.001).

Conclusion: The combination of DECT-derived morphological characteristics, iodine-related parameters, and clinical data helped accurately stratify PFS in LAGC before surgery and is associated with tumor angiogenesis.

Clinical Relevance Statement: Dual-energy CT was promising in the preoperative evaluation of the progression-free survival in LAGC patients after gastrectomy.