Diagnostic accuracy in NSCLC lymph node staging with Total-Body and conventional PET/CT

Area of Science:

• Nuclear Medicine
• Oncology
• Radiology

Background:

• Accurate nodal (N)-staging is crucial for non-small cell lung cancer (NSCLC) treatment decisions.
• Evaluating diagnostic accuracy of [18F]FDG Total-Body (TB) PET/CT versus short-axial field-of-view (SAFOV) PET/CT for N-staging in NSCLC.

Purpose of the Study:

• To characterize and compare the diagnostic accuracy indices of [18F]FDG TB and SAFOV PET/CT for N-staging in NSCLC patients.
• To assess the performance of both PET/CT modalities in identifying metastatic lymph nodes.

Main Methods:

• Prospective, single-center, cross-over, head-to-head comparative study.
• 48 NSCLC patients underwent both [18F]FDG TB and SAFOV PET/CT on the same day.
• Lymph node levels (n=700) correlated with a composite reference standard (histopathology or post-treatment imaging) for TP, FP, TN, FN analysis.

Main Results:

• Both TB and SAFOV PET/CT showed high diagnostic accuracy for patient-based N-staging.
• TB PET/CT demonstrated higher sensitivity (86.0% vs. 77.2%) and positive predictive value (81.7% vs. 72.1%) than SAFOV PET/CT, though not statistically significant.
• TB PET/CT resulted in fewer incorrect N-staging cases (1 vs. 6) and lower semi-quantitative thresholds (SUVmax 3.0, TBR 1.2, MTV 0.5 ml, TLG 1.0 ml) for detecting positive lymph nodes.

Conclusions:

• TB and SAFOV PET/CT exhibit high diagnostic accuracy for NSCLC N-staging.
• TB PET/CT shows a trend towards higher sensitivity and PPV, with a significantly lower rate of incorrect staging.
• TB PET/CT may be advantageous for detecting small, low [18F]FDG-avidity mediastinal lymph node metastases in NSCLC.