Objective: The aim of the current study was to investigate the predictive value of dual-time-point F-18 FDG PET/CT for pathologic N1 metastasis in patients with non-small cell lung cancer (NSCLC).
Methods: A retrospective review identified 70 patients with NSCLC patients who received dual-time-point F-18 FDG PET/CT at diagnosis of cancer. The F-18 FDG PET/CT findings for all primary NSCLC and mediastinal lymph node involvement were compared with the pathologic diagnosis within 5 weeks after surgical resection. The pathologic diagnoses of N1 state were confirmed by surgical resection. Univariate and multivariate analyses were used to analyze the associations among the pathologic N1 status and age, sex, tumor size, histology, standardized uptake value (SUVmaxE), SUVmaxD, and %ΔSUVmax.
Results: The N1 (+) group showed statistically significant higher value of SUVmaxE and SUVmaxD than N1 (−) group. The %ΔSUVmax did not show the statistical difference between pathologic N1 (+) and N1 (−) groups. Receiver operating characteristic analyses showed that the SUVmaxE was superior to the %ΔSUVmax for the prediction of pathologic N1 involvement in NSCLC. In univariate analysis, pathology (adenocarcinoma or nonadenocarcinoma), SUVmaxE (>6.9 or ≤6.9), SUVmaxD (>7.1 or ≤7.1) were factors significantly associated with pathologic N1 involvement. However, in multivariate analysis, only the SUVmaxE was factor significantly associated with pathologic N1 involvement in NSCLC.
Conclusions: Based on the presented results, the dual-time-point F-18 FDG PET/CT is not a useful method for the prediction of pathologic N1 status in NSCLC patients. Further studies are needed to confirm these results and improve statistical accuracy.