Prognostic value of whole-body total lesion glycolysis at pretreatment FDG PET/CT in non-small cell lung cancer

Abstract

Purpose: To determine whether whole-body total lesion glycolysis (TLG), which combines volumetric and metabolic information from fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT), can provide a better evaluation of the prognosis for non-small cell lung cancer (NSCLC).

Materials and methods: The institutional review board approved this retrospective study, and the requirement to obtain informed consent was waived. The authors identified 105 consecutive patients with NSCLC who underwent staging FDG PET/CT before any therapy. These patients were free of brain metastasis and underwent standard treatment and subsequent clinical follow-up. Metabolic tumor volume (MTV), mean standardized uptake value (SUV), and maximum SUV of each tumor over the whole body were determined. Whole-body MTV and whole-body TLG are the summation of all the MTVs and summation of individual tumor volume multiplied by its mean SUV, respectively. Univariate and multivariate analyses were performed to assess the prognostic significance of whole-body TLG and other factors, including whole-body MTV, lung TLG, lung MTV, maximum SUV, sex, age, performance status, histologic subtype, T stage, N stage, clinical stage, and treatment method.

Results: The median follow-up time was 3.1 years. The estimated median progression-free survival (PFS) and overall survival (OS) for the cohort was 10.8 months and 2.8 years, respectively. The 1-year PFS was 0.0% for patients with high whole-body TLG (>655) and 50.0% for those with low whole-body TLG (≤655). The 1-year OS was 58.8% for patients with high whole-body TLG and 84.1% for those with low whole-body TLG. Univariate analysis showed that whole-body TLG, whole-body MTV, lung TLG, lung MTV, maximum SUV, performance status, T stage, N stage, clinical stage, and treatment type (surgery vs other) were significant prognostic factors for PFS (P < .01 for all). With use of the forward stepwise multivariate Cox proportional hazards model, whole-body TLG (hazard ratio = 2.92; 95% confidence interval: 1.62, 5.26; P < .01) and surgical treatment (hazard ratio = 4.24; 95% confidence interval: 2.54, 7.07; P < .01) remained significant in PFS.

Conclusion: Whole-body TLG is of prognostic value for NSCLC. It may be a promising tool for stratifying patients with NSCLC for risk-adapted therapies.