Abstract: Objective  To explore the value of ¹⁸F-FDG PET-CT in evaluating the prognosis of locally advanced non-small cell lung cancer (NSCLC) patients. Methods  The clinical characteristics and ¹⁸F-FDG PET-CT parameters of 138 locally advanced NSCLC patients from 2013 to 2016 in Suzhou Municipal Hospital and People′s Hospital of Suzhou New District were analyzed retrospectively. The maximum standardized uptake value (SUV_max), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were measured. Area under the curve (AUC) of SUVmax, MTV and TLG were calculated to determine optimal cut-off value for patients grouping, with receiver-operating characteristic curve (ROC) analysis. Progression-free survival (PFS) and overall survival (OS) were assessed by Kaplan-Meier method and the survival difference between the two groups was estimated by log-rank test. Multivariate survival analysis was performed by Cox proportional hazard model. Results  According to ROC analysis, SUVmax (AUC=0.716, cut-off value was 11.8, P<0.001) had a better predictive value for OS, whereas the predictive values of MTV (AUC=0.580, P=0.101) and TLG (AUC=0.635, P=0.005) were less. There was no significant correlation between SUV_max and patients′ age (χ²=1.222, P=0.269), gender (χ²=0.029, P=0.865), TNM stage (χ²=0.073, P=0.787), pathologic subtype (χ²=0.541, P=0.462), smoking (χ²=0.266, P=0.606), differentiation (χ²=0.285, P=0.593) or tumor location (χ²=0.509, P=0.476). The 1-year, 2-year and 3-year OS rates of low SUVmax group (n=59) were 93.2%, 67.0% and 15.6% respectively, and those of high SUV_max group (n=79) were 77.2%, 25.0% and 5.62% respectively. The OS rate of low SUV_max group was higher than that of high SUV_max group (χ²=19.153, P<0.001). The 1-year and 2-year PFS rates of low SUV_max group were 79.3% and 56.9% respectively, and those of high SUV_max group were 46.2%, 13.0% respectively. The PFS rate of low SUV_max group was higher than that of high SUV_max group (χ²=25.945, P<0.001). Single factor analysis showed that differentiation (HR=1.839, 95%CI: 1.161-2.913, P=0.017), SUV_max (HR=0.357, 95%CI: 0.231-0.550, P<0.001), MTV (HR=0.470, 95%CI: 0.270-0.819, P=0.001) and TLG (HR= 0.508, 95%CI: 0.327-0.789, P=0.002) were independent influencing factors of OS. The degree of differentiation (HR=1.909, 95%CI: 1.167-3.123, P=0.018) and SUV_max (HR=0.250, 95%CI: 0.160-0.410, P<0.001) were the independent influencing factors of PFS. Multivariate analysis showed that only SUV_max was an independent influencing factor of OS (HR=2.189, 95%CI: 1.222-3.189, P=0.008）and PFS (HR=4.412, 95%CI: 2.318-8.398, P<0.001). Conclusion  PET-CT SUV_max of primary tumor is significantly correlated with OS and PFS of patients. It has important guiding value for prognosis judgment and treatment plan selection of patients with locally advanced NSCLC.

Key words: Carcinoma, non-small-cell lung, ¹⁸F-FDG PET-CT, Prognosis