18F-FDG PET/CT and circulating tumor cells in treatment-naive patients with non-small-cell lung cancer

Abstract

Purpose: This study retrospectively investigated the clinical utility of 2-deoxy-18F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) and circulating tumor cells (CTCs) in the diagnosis and prognosis of treatment-naive patients with non-small-cell lung cancer (NSCLC).

Methods: The blood samples of treatment-naive patients with NSCLC were collected for CTCs detection, and the tumor metabolic parameters of ¹⁸F-FDG PET/CT, including maximum standard uptake value (SUVmax), metabolic tumor volume of primary lesion (MTV-P) and combination of primary lesion and metastases (MTV-C), and total lesion glycolysis of primary lesion (TLG-P) and combination of primary lesion and metastases (TLG-C), were analyzed. Age, sex, smoking, serum tumor markers, tumor size, location, TNM stage, and genetic mutations were also reviewed. Moreover, progression-free survival (PFS) and overall survival (OS) of these patients were analyzed.

Results: A total of 309 patients with NSCLC (200 men, 109 women; mean age: 61 ± 9 years) were enrolled in this study, including 217 patients with adenocarcinoma and 92 with squamous cell carcinoma. Of the 309 cases, 11 were misdiagnosed with benign diseases by ¹⁸F-FDG PET/CT. CTCs positivity was detected in 234 cases. The sensitivity of ¹⁸F-FDG PET/CT and CTCs in NSCLC were 96.4% and 75.7%, respectively. SUVmax, MTV-P, TLG-P, MTV-C, TLG-C, tumor size, and serum CYFRA211 levels were significantly higher in CTCs positive group than negative group; and advanced TNM stage, squamous cell carcinoma, and EGFR wild type presented higher CTCs positivity. Multivariate logistic regression analysis revealed that SUVmax was significantly associated with CTCs positivity. Multivariate cox regression analysis showed that TLG-P, TLG-C, and CTCs were independent predictors of PFS in patients with NSCLC, and TLG-C and CTCs were independent predictors of OS.

Conclusions: ¹⁸F-FDG PET/CT was superior to CTCs in the diagnosis of treatment-naive patients with NSCLC. The levels of CTCs in the peripheral blood were associated with tumor glucose metabolism in NSCLC. Metabolic parameters of ¹⁸F-FDG PET/CT and CTCs could separately predict the outcomes of treatment-naive patients with NSCLC.

Keywords: 18F-FDG PET/CT; Circulating tumor cells (CTCs); Diagnosis; Non-small-cell lung cancer (NSCLC); Prognosis.