Prognostic potential of integrated morphologic and metabolic parameters of pre-therapeutic [18F]FDG-PET/CT regarding progression-free survival (PFS) and overall survival (OS) in NSCLC-patients

Purpose This study aimed to evaluate the prognostic potential of pre-therapeutic [F-18]FDG-PET/CT variables regarding prediction of progression-free survival (PFS) and overall survival (OS) in NSCLC-patients. Method NSCLC-patients who underwent pre-therapeutic [F-18]FDG-PET/CT were retrospectively analyzed. The following imaging features were collected from the primary tumor: tumor size, tumor density, central necrosis, spicules and SUVmax. For standardization, an indexSUV(max) was calculated (SUVmax primary tumor/SUVmax liver). Descriptive statistics and correlations of survival time analyses for PFS and OS were calculated using the Kaplan-Meier method and Cox regression including a hazard ratio (HR). A value of p < 0.05 was set as statistically significant. The 95%-confidence intervals (CI) were calculated. The median follow-up time was 63 (IQR 27-106) months. Results This study included a total of 82 patients (25 women, 57 men; mean age: 66 +/- 9 years). IndexSUV(max) (PFS: HR = 1.0, CI: 1.0-1.1, p = 0.49; OS: HR = 1.0, CI: 0.9-1.2, p = 0.41), tumor size (PFS: HR = 1.0, CI: 0.9-1.0, p = 0.08; OS: HR = 1.0, CI: 0.9-1.0, p = 0.07), tumor density (PFS: HR = 0.9, CI: 0.6-1.4, p = 0.73; OS: HR = 0.3; CI: 0.1-1.1; p = 0.07), central necrosis (PFS: HR = 1.0, CI: 0.6-1.8, p = 0.98; OS: HR = 0.6, CI: 0.2-1.9, p = 0.40) and spicules (PFS: HR = 1.0, CI: 0.6-1.9, p = 0.91; OS: HR = 1.3, CI: 0.4-3.7, p = 0.65) did not significantly affect PFS and OS in the study population. An optimal threshold value for the indexSUV(max) was determined by ROC analysis and Youden's index. There was no significant difference in PFS with an indexSUV(max)-threshold of 3.8 (13 vs. 27 months; p = 0.45) and in OS with an indexSUV(max)-threshold of 4.0 (113 vs. 106 months; p = 0.40). Conclusions SUVmax and morphologic parameters from pre-therapeutic [F-18]FDG-PET/CT were not able to predict PFS and OS in NSCLC-patients.