F-18-FDG PET/CT quantitative parameters as prognostic factor in localized and inoperable lung cancer

Aim: To assess the utility of F-18-FDG PET/CT quantitative parameters as prognostic factor in patients diagnosed with localized and inoperable lung cancer treated by stereotactic body radiotherapy (SBRT). Material and methods: Fifty patients (42 men) diagnosed in the last 7 years with early-stage lung cancer and treated with SBRT alone were assessed by a prospective study. After PET/CT study, metabolic parameters maximum SUV (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were determined at different thresholds. The prognostic factors for overall survival (OS), cause-specific survival (CS) and disease-free survival (DFS) were analysed by Cox proportional hazards model and the survival analysis by Kaplan-Meier method. Results: The average follow-up was 39.6 months, with 21 recurrences and 24 dead. Univariate analysis determined MTV30 and MTV40 as predictors for OS; MTV30, MTV40, TLG30 and TLG40 for CS, and MTV2, MTV30, MTV40, TLG2, TLG30 and TLG40 for DFS. Survival analysis found statistically significant differences for CS and DFS depending on tumor size and for DFS considering the cut-off values of MTV2 and TLG2 (threshold SUVmax = 2). SUVmax, age and sex were not shown to be significant factors. Conclusion: Pre-treatment quantitative assessment using metabolic parameters MTV2 and TLG2 as well as tumor size proved to be prognostic factors in patients diagnosed with localized and inoperable lung cancer treated by SBRT. Results could help to personalize treatment. (c) 2020 Sociedad Espanola de Medicina Nuclear e Imagen Molecular. Published by Elsevier Espana, S.L.U. All rights reserved.