FDG PET/CT tumor dissemination characteristic predicts the outcome of first-line systemic therapy in non-small cell lung cancer

Introduction: To explore the correlation between the tumor dissemination characteristic at ¹⁸F-FDG PET/CT images and the outcome of first-line systemic therapy for stage IV non-small cell lung cancer (NSCLC).

Methods: The current retrospective study included 101 NSCLC patients receiving first-line systemic therapy with baseline ¹⁸F-FDG PET/CT images available. The distance between the two lesions that were the farthest apart, whether they were primary or secondary, was defined as D_max to calculate the tumor dissemination. The tumor metabolic volume (MTV) of the primary tumor and the MTV of the whole-body tumor lesions (MTV_wb) were calculated using PET/CT imaging. The Kaplan–Meier survival analyses and COX predictive model were performed to assess the relationship between the parameters and survival.

Results: D_max and MTV_wb were independent prognostic factors for OS (P=0.019 and P=0.011, respectively) and PFS (P=0.043 and P=0.009, respectively). Poor PFS and OS were associated with high MTV_wb (>54 cm³) and high D_max (>48.5 cm) (P = 0.006 and P = 0.008, respectively). When MTV_wb and D_max were combined, three risk groups were stratified with no (score 0), one (score 1), or two (score 2) factors (P<0.001 for PFS, P<0.001 for OS). The group with a score of 0 had a considerably longer PFS and OS than those who received a score of 1 or 2 (PFS: 61.1%, 43.5%, and 21.1%, respectively, OS: 77.8%, 54.3%, and 36.8%, respectively).

Conclusions: The combination of tumor dissemination characteristic (D_max) tumor burden (MTV_wb) and can further improve the prognosis stratification of NSCLC.