The impact of radiometabolic features on the stage and survival in small cell lung cancer.

BACKGROUND

Small-cell lung cancer (SCLC) is a highly aggressive malignancy with a poor prognosis. 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) plays a critical role in staging, as elevated FDG uptake is associated with tumor aggressiveness and metabolic activity. Although radiometabolic parameters such as maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) have been proposed as prognostic markers, existing data remain inconsistent. This study aimed to investigate the association between these parameters and disease stage and overall survival (OS) in SCLC patients.

METHODS

Patients diagnosed with lung cancer between May 2022 and June 2023 were retrospectively reviewed and divided into two groups: those with SCLC (Group 1) and those with non-SCLC (Group 2). Demographic, clinical, radiological (thoracic CT), and radiometabolic (PET/CT) features, treatment history, staging, and mortality data (based on the national death registry) were collected.

RESULTS

A total of 111 patients (mean age: 65.2 years) were included, of whom 65 (58.6%) had SCLC. In the SCLC group, 55 (85.9%) had extensive-stage disease and 9 (14.1%) had limited-stage disease. Mean SUVmax, MTV, and TLG values were significantly higher in extensive-stage disease (12.5, 87.2, and 624.2, respectively) than in limited-stage disease (7.1, 7.0, and 37.0) (P < 0.05). Median OS was 12.5 months. Cutoff values for poor prognosis were identified as SUVmax ≥10, MTV ≥40, and TLG ≥170, with significantly shorter OS observed above these thresholds (P < 0.05). While SUVmax alone was not an independent predictor of survival (P > 0.05), MTV and TLG were identified as significant prognostic indicators in multivariate analysis (P < 0.05).

CONCLUSION

In SCLC, higher SUVmax values are associated with advanced disease stage. However, MTV and TLG may serve as more reliable independent prognostic biomarkers for survival.