The increment in standardized uptake value determined using dual-phase 18F-FDG PET is a promising prognostic factor in non-small-cell lung cancer.

Abstract

We aimed to determine whether the increment in the maximal standardized uptake value (SUVmax) of the primary lung tumour between the initial and delayed imaging by dual-phase (18)F-FDG PET has prognostic value in patients with non-small-cell lung cancer (NSCLC). We reviewed the records of patients with NSCLC who underwent pretreatment dual-phase (18)F-FDG PET/CT scans acquired at 1 h and 2 h after injection. The SUVmax increment (SUVinc) of the primary lung tumour was the 2-h SUVmax minus the 1-h SUVmax. Univariate and multivariate analyses were used to assess the prognostic significance of SUVinc, retention index, whole-body total metabolic tumour volume, whole-body total lesion glycolysis (TLGwb), 1-h SUVmax, 2-h SUVmax, gender, age, performance status, histological subtype, T stage, N stage and clinical stage. The records of 187 consecutive patients were reviewed. The median follow-up time was 3.9 years. The estimated median progression-free survival (PFS) and overall survival (OS) were 1.3 years and 4.4 years, respectively. An SUVinc cut-off value of >1 had the best discriminative yield for PFS. The 3-year PFS and OS were 61.6 % and 87.8 % in patients with SUVinc ≤ 1 versus 21.1 % and 46.2 % in patients with SUVinc >1 (all P < 0.01). Using the forward stepwise multivariate Cox proportional hazards model, SUVinc, TLGwb, and clinical stage were significant factors for PFS (all P < 0.01). A subgroup analysis of 117 patients treated with surgery showed that SUVinc (P = 0.02) and clinical stage (P < 0.01) were significant prognostic factors for PFS. Furthermore, in stage I patients treated with surgery alone, SUVinc was the only significant prognostic factor (HR 28.07; 95 % CI 2.42 - 326.41). SUVinc determined from dual-phase (18)F-FDG PET is a promising prognostic factor for NSCLC. It adds to the value of dual-phase (18)F-FDG PET.