Value of interim F-FDG PET/CT for predicting progression-free survival in stage ⅢB/IV EGFR-mutant non-small-cell lung cancer patients with EGFR-TKI therapy.

OBJECTIVES

We retrospectively investigated the prognostic value of FDG-PET performed for patients with Stage ⅢB/IV EGFR-mutant non-small-cell lung cancer (NSCLC) receiving EGFR tyrosine kinase inhibitor (TKI) therapy.

METHODS

A total of 78 patients newly diagnosed with Stage ⅢB/IV EGFR-mutant NSCLC who received baseline and interim PET/CT examination and were treated with EGFR-TKI therapy were included. Interim PET was performed after 4-6 weeks of treatment. Cox proportional hazards regression analysis was used to assess the association between quantitative F-FDG PET/CT parameters, other clinicopathological factors and progression-free survival (PFS), non-durable clinical benefit (non-DCB). Five interim PET variables were analyzed in this study in the prediction of non-DCB.

RESULTS

The one-year and two-year progression-free survival rates of the patients were 33.9% (28.6-39.2%) and 20.7% (16.1-25.3%), respectively. Multivariable analysis indicated that interim PET relevant factors ΔSUVmax (p = 0.002, p = 0.014) and ΔSUVmean (p = 0.000, p = 0.030) were independent risk factors for predicting the PFS or non-DCB of patients receiving EGFR-TKI treatment. The optimal cutoff values of the parameters in the tumor survival analyses were 56.74% for ΔSUVmax (p = 0.002) and 36.48% for ΔSUVmean (p = 0.001). ΔSUVmax had the highest diagnostic value in the prediction of non-DCB. The one-year progression-free survival rates (95% confidence intervals) of patients with ΔSUVmax ≥ 56.74% and ΔSUVmax <56.74% were 59.5% (44.2-74.8%) and 5.7% (0.0-13.3%), respectively (p = 0.000).

CONCLUSION

An early PET scan after 4-6 weeks can effectively predict the PFS and non-DCB of patients with Stage ⅢB/IV EGFR-mutant NSCLC receiving EGFR-TKI therapy.