Correlating Quantitative Para-Aortic Lymph Node Computed Tomography Parameters With Fluorodeoxyglucose Positron...

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Para-aortic nodes (PANs) are critical for cervical cancer staging.
• Accurate assessment of PANs is essential for treatment planning.
• Computed tomography (CT) and positron emission tomography (PET)/CT are used to evaluate PANs.

Purpose of the Study:

• To identify quantitative morphological parameters on CT that best correlate with fluorodeoxyglucose (FDG)-avid PANs in cervical cancer patients.
• To compare the diagnostic accuracy of different CT-derived parameters for detecting metastatic PANs.

Main Methods:

• Retrospective analysis of 94 cervical cancer patients who underwent pretreatment PET/CT and CT.
• Node-by-node correlation of CT measurements (short- and long-axis diameters, volume, L/S ratio) with FDG avidity on PET/CT.
• Calculation of the area under the receiver operator curve (AUC) to assess diagnostic accuracy.

Main Results:

• Para-aortic lymph node volume showed the highest diagnostic accuracy (AUC = 0.945) compared to short axis (0.895), long axis (0.885), and L/S ratio (0.583).
• At 90% specificity, a volume cutoff of 0.443 cm³ achieved 85% sensitivity for detecting FDG-avid PANs.
• Short-axis diameter cutoff of 5.9 mm achieved 75% sensitivity at 90% specificity.

Conclusions:

• Para-aortic lymph node volume on CT is a superior quantitative parameter for detecting metastatic disease compared to other CT-derived measurements.
• Node volume provides an improved correlation between CT and PET/CT findings.
• This CT-based volume assessment offers a valuable alternative for detecting suspicious PANs in settings without PET/CT access.