Determination of arterial invasion in pancreatic ductal adenocarcinoma: what is the best diagnostic criterion on CT?

ObjectivesTo investigate the diagnostic performance and interobserver variability in the determination of arterial invasion in pancreatic ductal adenocarcinoma (PDAC) and determine the best CT imaging criterion.MethodsWe retrospectively evaluated 128 patients with PDAC (73 men and 55 women) who underwent preoperative contrast-enhanced CT. Five board-certified radiologists (expert) and four fellows (non-expert]) independently assessed the arterial invasion (celiac, superior mesenteric, splenic, and common hepatic arteries) using a 6-point score: 1, no tumor contact; 2, hazy attenuation <= 180 degrees; 3, hazy attenuation > 180 degrees; 4, solid soft tissue contact <= 180 degrees; 5, solid soft tissue contact > 180 degrees; and 6, contour irregularity. ROC analysis was performed to evaluate the diagnostic performance and determine the best diagnostic criterion for arterial invasion, with pathological or surgical findings as references. Interobserver variability was assessed using Fleiss's kappa statistics.ResultsAmong the 128 patients, 35.2% (n = 45/128) received neoadjuvant treatment (NTx). Solid soft tissue contact <= 180 degrees was the best diagnostic criterion for arterial invasion as defined by the Youden Index both in patients who did and did not receive NTx (sensitivity, 100% vs. 100%; specificity, 90% vs. 93%; and AUC, 0.96 vs. 0.98, respectively). Interobserver variability among the non-expert was not inferior to that among the expert (kappa = 0.61 vs 0.61; p = .39 and kappa = 0.59 vs 0.51; p < .001 in patients treated with and without NTx, respectively).ConclusionsSolid soft tissue contact <= 180 degrees was the best diagnostic criterion for the determination of arterial invasion in PDAC. Considerable interobserver variability was seen among the radiologists.

Automated summary

This study aimed to investigate the accuracy and interobserver variability in the diagnosis of arterial invasion in pancreatic ductal adenocarcinoma (PDAC) and determine the best criterion for CT imaging. The findings showed that solid soft tissue contact ≤ 180 degrees was the best diagnostic criterion for arterial invasion in PDAC. The study also revealed considerable interobserver variability among radiologists.