Indeterminate Lymph Nodes Assessment in Oral Squamous Cell Carcinoma Using CT, MRI, and PET-CT: A Retrospective Study

Area of Science:

• Oncology
• Radiology
• Diagnostic Imaging

Background:

• Oral squamous cell carcinoma (OSCC) management relies on accurate staging of cervical lymph node metastasis.
• Computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography-computed tomography (PET-CT) are used for nodal staging, but their performance varies, especially for indeterminate nodes.

Purpose of the Study:

• To compare the diagnostic performance of CT, MRI, and PET-CT in detecting metastatic cervical lymph nodes in OSCC patients.
• To evaluate the utility of these imaging modalities in identifying radiologically indeterminate lymph nodes.

Main Methods:

• Retrospective analysis of OSCC patients who underwent CT, MRI, and PET-CT prior to surgery.
• Histopathologic confirmation served as the reference standard.
• Diagnostic accuracy, sensitivity, and specificity were calculated for each modality.

Main Results:

• Excluding indeterminate nodes, CT had 83.6% accuracy, 51.9% sensitivity, and 92.4% specificity. MRI and PET-CT had similar accuracies and sensitivities.
• PET-CT showed higher sensitivity (86.8%) for benign nodes but lower specificity (55.8%) compared to CT and MRI.
• SUVmax was a significant predictor of malignancy (OR 1.71, AUC 0.88), with an optimal cutoff of 3.6.

Conclusions:

• PET-CT offers superior sensitivity for detecting benign and indeterminate lymph nodes in OSCC, complementing CT's high specificity.
• SUVmax is a valuable quantitative marker for metastatic involvement.
• A multimodal imaging approach may improve diagnostic accuracy for challenging cases.