Preoperative CT Assessment of Portal Vein Contact Length Predicts Poor Prognosis in Resectable Pancreatic Head Cancer

To investigate whether preoperative computed tomography (CT)-based tumor-portal/superior mesenteric vein (PV/SMV) contact angle and contact length predict pathological venous invasion and refine prognostic stratification in anatomically resectable pancreatic ductal adenocarcinoma (R-PDAC).

We retrospectively reviewed 108 patients who underwent upfront pancreaticoduodenectomy without neoadjuvant chemotherapy for pancreatic head PDAC, including 101 anatomically resectable cases and 7 borderline resectable cases with PV involvement (BR-PV). Tumor-PV/SMV contact angle and contact length were measured on multidetector CT. Their associations with pathological PV/SMV invasion, PV/SMV resection, and overall survival (OS) were analyzed.

Both contact angle and contact length predicted pathological venous invasion, with optimal cutoff values of 90° for angle (AUC = 0.86) and 15 mm for length (AUC = 0.84), and both were significantly associated with pathological venous invasion and PV/SMV resection (all p < 0.001). In the subgroup with R-PDAC, however, only contact length provided meaningful prognostic stratification. Patients with contact length ≥ 15 mm had significantly worse OS than those with contact length < 15 mm (p = 0.0032) or no contact (p < 0.001), and their survival was comparable to that of BR-PV patients (p = 0.8548). In multivariable analysis, contact length ≥ 15 mm remained an independent adverse prognostic factor (HR 2.79, 95% CI 1.64-4.73, p < 0.001).

Preoperative CT-based assessment of tumor-PV/SMV contact length may serve as a practical marker for identifying a high-risk subgroup within R-PDAC and may help refine selection of patients for neoadjuvant treatment.