Objectives: Small cell lung cancer (SCLC) and extrapulmonary small cell carcinoma (EPSCC) are rare, aggressive neuroendocrine tumours with poor prognosis. This study aimed to assess the prognostic role of FDG PET/CT–derived biomarkers, including SUVmax, metabolic tumour volume (MTV), and total lesion glycolysis (TLG). Material and Methods: This ambispective study analysed Patients with histologically confirmed SCLC or EPSCC who underwent baseline FDG PET/CT. Quantitative PET parameters (SUVmax, MTV, and TLG) were extracted, and clinical details were recorded. Progression-free survival (PFS) and overall survival (OS) were evaluated using Kaplan–Meier and Cox regression analyses. receiver operating characteristic (ROC) curve analysis was performed to derive optimal cut-off values for prognostic stratification. Results: High baseline MTV and TLG were significantly associated with shorter PFS and OS, whereas SUVmax showed limited predictive value. ROC-derived thresholds for MTV and TLG effectively separated patients into high- and low-risk groups with distinct survival outcomes (log-rank p < 0.001). On multivariate analysis, MTV and TLG retained independent prognostic significance, outperforming conventional clinical variables. Conclusion: Quantitative FDG PET/CT parameters, particularly MTV and TLG, are strong prognostic biomarkers in SCLC and EPSCC. Integration of these metrics into clinical assessment may improve risk stratification and guide treatment planning.
Sarswat et al. (Mon,) studied this question.