Interobserver variability in lymph node evaluation with endoscopic ultrasonography in cholangiocarcinoma

Area of Science:

• Gastroenterology
• Surgical Oncology
• Diagnostic Imaging

Background:

• Accurate preoperative lymph node (LN) assessment is critical for intrahepatic cholangiocarcinoma (iCCA) and perihilar cholangiocarcinoma (pCCA) management.
• Metastatic LNs significantly reduce survival rates and can preclude surgical resection.
• Endoscopic ultrasound (EUS) offers a minimally invasive method for LN evaluation and tissue acquisition.

Purpose of the Study:

• To evaluate interobserver agreement among endosonographers in characterizing LNs in iCCA and pCCA patients.
• To assess the reliability of EUS in identifying malignant LNs preoperatively.

Main Methods:

• A cross-sectional survey involving 24 endosonographers.
• Review of 42 EUS images from iCCA and pCCA patients.
• Classification of LNs based on demarcation, shape, echogenicity, homogeneity, suspiciousness, and need for tissue retrieval; interobserver agreement analyzed using Light's kappa statistics.

Main Results:

• Moderate to fair agreement was observed for LN characteristics (Kappa values ranging from 0.24 to 0.52).
• Overall accuracy in identifying malignant LNs was 62% (range: 44%-75%).
• Sensitivity was 60% (range: 29%-90%) and specificity was 64% (range: 28%-89%).

Conclusions:

• Significant variability exists among endosonographers in EUS-based LN assessment for iCCA and pCCA.
• Standardization of preoperative LN evaluation, including objective criteria for tissue acquisition (e.g., short-axis diameter), is necessary.
• Further research is needed to refine EUS guidelines for improved diagnostic accuracy.