Prognostic superiority of volumetric PET parameters (MTV and TLG) over SUV in advanced non-small-cell lung cancer: a systematic review and meta-analysis of univariate and multivariate evidence.

PURPOSE: To systematically assess the prognostic significance of baseline 18F-fluorodeoxyglucose positron emission tomography/computed tomography ([18F] FDG PET/CT) metabolic parameters in patients with non-small cell lung cancer (NSCLC) undergoing immune checkpoint inhibitor (ICI) therapy. METHODS: A systematic search of five core databases was conducted up to March 2026. Relevant data concerning NSCLC patient characteristics, metabolic [18F] FDG PET/CT parameters, and survival outcomes were extracted. Hazard ratios (HRs) were pooled to assess the prognostic significance of maximum standardised uptake value (SUVmax), mean standardised uptake value (SUVmean), metabolic tumour volume (MTV), and total lesion glycolysis (TLG) regarding overall survival (OS) and progression-free survival (PFS). RESULTS: A total of 33 studies were eligible for inclusion. Univariable analysis showed no prognostic value for SUVmax and SUVmean. Conversely, elevated MTV and TLG were associated with inferior PFS (MTV: HR = 1.71,95% CI: 1.39-2.11; TLG: HR = 1.84, 95%CI: 1.31-2.57) and OS (MTV: HR = 1.80, 95%CI: 1.40-2.33; TLG: HR = 1.92, 95%CI: 1.18-3.12) (P < 0.01), particularly when cut-off values ranged of 50-100cm3 for MTV (PFS: HR = 1.71, 95%CI: 1.16-2.52; OS: HR = 2.23, 95%CI: 1.42-3.51). Multivariable Cox regression analysis further identified MTV as a robust independent predictor of both PFS (HR = 1.21, 95%CI: 1.07-1.36) and OS (HR = 1.14, 95%CI: 1.03-1.26). While TLG maintained independent prognostic significance for PFS (HR = 1.46, 95%CI: 1.10-1.94), it failed to reach statistical significance regarding OS (HR = 1.00, 95%CI: 0.99-1.01) (P > 0.01). Notably, subgroup analyses demonstrated that the prognostic efficacy of MTV and TLG was further pronounced in patients presenting with Stage IV disease, those undergoing first-line treatment, or those managed with chemoimmunotherapy regimens. CONCLUSION: Baseline MTV is an independent prognostic factor for PFS and OS in NSCLC patients treated with ICIs, with a cut-off value within the range of 50-100 cm³ demonstrating optimal predictive performance. In contrast, the predictive significance of TLG for OS was not maintained after multivariable adjustment. SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/PROSPERO/view/CRD420261375745, identifier CRD420261375745.