Prognostic value of SUVmax measurements obtained by FDG-PET in patients with non-small cell lung cancer receiving chemotherapy

[¹⁸F]Fluorodeoxyglucose (FDG) uptake has been shown to correlate well with tumor proliferation rates. In patients with non-small cell lung cancer (NSCLC) receiving chemotherapy, we analyzed the relationships between the maximum standardized uptake value (SUVmax) obtained by FDG positron emission tomography (FDG-PET) and other clinical factors, and examined whether or not SUVmax could predict progression-free survival (PFS) and/or overall survival (OS). This retrospective study involved 62 consecutive NSCLC patients (35 male and 27 female: median age, 65 years). All patients underwent FDG-PET examination before treatment. As the first-line treatment, the patients received chemotherapy with (n = 15) or without (n = 47) radiotherapy. Survival curves were obtained by the Kaplan-Meier method, and differences in survival between subgroups were analyzed by the log-rank test and the Cox proportional hazards model. Significant correlations were observed between SUVmax and gender (P = 0.006), histology (P < 0.001), smoking status (P = 0.049), stage (P = 0.015), and treatment modality (P = 0.008), but not other factors, including age (P = 0.402) and performance status (P = 0.421). The median SUVmax was 5.1 (25-75th percentile: 3.45-7.0) in patients with adenocarcinoma and 8.3 (25-75th percentile: 6.9-9.9) in those with other types of NSCLC. Adenocarcinomas showed significantly lower SUVmax than the other tumor types (P < 0.001). Cox analysis adjusting for possible confounding factors, including gender, smoking status, histology and stage, demonstrated that the hazard ratios increased as the SUVmax increased in terms of both PFS (P = 0.008) and OS (P = 0.045), indicating that SUVmax predicts outcome independently of other clinical factors, such as histology and stage. Our findings indicate that FDG-PET examination can provide information useful for prognostication in NSCLC.