A comparison of enhancement patterns on dynamic enhanced CT and survival between patients with pancreatic neuroendocrine tumors with and without intratumoral fibrosis

Abstract

Purpose To compare CT findings and survival between patients with pancreatic neuroendocrine tumors (pNETs) with and without fibrosis.

Methods Forty-five pNET patients with intratumoral fibrosis (group A) were matched for age, gender, and tumor size and grade with 45 pNET patients without (group B), and CT images were retrospectively reviewed. Hounsfield units (HUs) of tumors in unenhanced, arterial and portal phases, HU ratio (tumor to normal parenchyma) in each phase, enhancement patterns, visible enhancement pattern changes, and survival were compared.

Results Group A showed progressive enhancement patterns, while group B showed early enhancement and wash-out patterns (p < 0.05). HUs of tumors and HU ratio in the unenhanced phase were significantly higher in group A than group B (p ≤ 0.024), whereas those in the arterial phase were significantly lower in group A than group B (p ≤ 0.003). Peripheral to full or peripheral to peripheral enhancement change was more frequent in group A, while full to full enhancement change was more frequent in group B (p < 0.05). Group A showed significantly lower overall survival than group B (p = 0.029).

Conclusions pNETs with fibrosis showed a progressive enhancement pattern and worse overall survival than pNETs without, which showed an early enhancement and wash-out pattern.