Diagnostic performance of node-RADS classification for primary lymph node assessment in rectal cancer: a modality...

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Accurate staging of rectal cancer is crucial for treatment planning.
• Lymph node involvement (LNI) is a key prognostic factor.
• Current imaging methods for LNI assessment have limitations.

Purpose of the Study:

• To evaluate the diagnostic performance of the Node Reporting and Data System (Node-RADS) for LNI in early-stage rectal cancer.
• To compare Node-RADS performance across contrast-enhanced CT (CE-CT), T2-weighted MRI (T2WI), and contrast-enhanced T1-weighted MRI (T1CE).

Main Methods:

• Retrospective analysis of 113 rectal cancer patients who underwent surgery without neoadjuvant therapy.
• Independent assessment of lymph nodes by two radiologists using Node-RADS.
• Histopathology served as the reference standard.
• Diagnostic performance evaluated using ROC curve analysis and McNemar test.

Main Results:

• Node-RADS demonstrated superior diagnostic performance compared to short-axis diameter (SAD) measurements across all imaging modalities (AUCs ranging from 0.838 to 0.853).
• Node-RADS achieved high sensitivity (76.19%-78.57%) and specificity (91.55%-92.96%) for LNI detection.
• No significant differences in diagnostic performance were observed among CE-CT, T2WI, and T1CE using Node-RADS.

Conclusions:

• Node-RADS is a superior tool for diagnosing LNI in primary rectal cancer compared to SAD measurements.
• Node-RADS exhibits consistent diagnostic effectiveness across CE-CT, T2WI, and T1CE modalities.
• The findings support the integration of Node-RADS into routine rectal cancer staging.