Metabolic Tumor Volume Measured by F-18 FDG PET/CT can Further Stratify the Prognosis of Patients with Stage IV Non-Small Cell Lung Cancer

Purpose

This study aimed to further stratify prognostic factors in patients with stage IV non-small cell lung cancer (NSCLC) by measuring their metabolic tumor volume (MTV) using F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT).

Materials and Methods

The subjects of this retrospective study were 57 patients with stage IV NSCLC. MTV, total lesion glycolysis (TLG), and maximum standardized uptake value (SUVmax) were measured on F-18 FDG PET/CT in both the primary lung lesion as well as metastatic lesions in torso. Optimal cutoff values of PET parameters were measured by receiver operating characteristic (ROC) curve analysis. Kaplan-Meier survival curves were used for evaluation of progression-free survival (PFS). The univariate and multivariate Cox proportional hazards models were used to select the significant prognostic factors.

Results

Univariate analysis showed that both MTV and TLG of primary lung lesion (MTV-lung and TLG-lung) were significant factors for prediction of PFS (P < 0.001, P = 0.038, respectively). Patients showing lower values of MTV-lung and TLG-lung than the cutoff values had significantly longer mean PFS than those with higher values. Hazard ratios (95 % confidence interval) of MTV-lung and TLG-lung measured by univariate analysis were 6.4 (2.5–16.3) and 2.4 (1.0–5.5), respectively. Multivariate analysis revealed that MTV-lung was the only significant factor for prediction of prognosis. Hazard ratio was 13.5 (1.6–111.1, P = 0.016).

Conclusion

Patients with stage IV NSCLC could be further stratified into subgroups of significantly better and worse prognosis by MTV of primary lung lesion.