Prognostic Value of 18F-FDG Uptake on Positron Emission Tomography in Patients with Pathologic Stage I Non-small Cell Lung Cancer

Introduction: The intensity of F-18-fluorodeoxyglucose (F-18-FDG) uptake in positron emission tomography could be of prognostic significance for patients with non-small cell lung cancer (NSCLC). The aim of this retrospective study was to evaluate the prognostic value of the FDG uptake in patients with resected pathologic stage I NSCLC according to histologic types of the tumors. Methods: For each patient, a maximum standardized uptake value (SUVmax) and a partial volume corrected (PVC) SUVmax were calculated for the primary lesion on positron emission tomography. To find optimal cutoff values for cancer recurrences, receiver operating characteristic curves were used. Results: Among 145 study patients, the mean values of SUVmax were 7.7 in those with adenocarcinoma (n = 70) and 16.0 in those with other histologies (n = 75; p < 0.001). Furthermore, the optimal cutoff values of SUVmax to predict cancer recurrences were identified as 5.2 in patients with adenocarcinoma and 13.8 in those with other histologies. In whole patients with pathologic stage I NSCLC, SUVmax (p = 0.025), PVC SUVmax (p = 0.014), tumor size (p = 0.048), and weight loss (p = 0.041) were significantly associated with disease-free survival (DFS). Moreover, PVC SUVmax (p = 0.034) and SUVmax (p = 0.012) were significantly associated with DFS in the multivariate analyses. Conclusions: The intensity of FDG uptake for the primary tumor was an independent prognostic factor for DFS in whole patients with pathologic stage I NSCLC. However, caution is needed for the interpretation of optimal cutoff values of SUVmax according to tumor histologies.