¹⁸F-FDG uptake on PET is a predictive marker of thymidylate synthase expression in patients with thoracic neoplasms

Predictive and Prognostic Value of 18F-fluorodeoxyglucose Uptake Combined with Thymidylate Synthase Expression in Patients with Advanced Non-Small Cell Lung Cancer

We investigated the relationship between tumor ¹⁸F-fluorodeoxyglucose (FDG) uptake on positron emission tomography/computed tomography (PET/CT) scans and thymidylate synthase (TS) expression. In addition, we evaluated the value of FDG uptake in predicting treatment response and prognosis when combined with TS expression in patients with advanced non-small cell lung cancer (NSCLC). We measured the maximum standard uptake value, metabolic tumor volume, and total lesion glycolysis (TLG) of tumor lesions on pretreatment scan in 234 patients (age: 60.1 ± 9.4 years; males: 56.4%) with stage IV non-squamous NSCLC who were enrolled in the prospective phase II clinical trial. We investigated the correlation of the parameters with TS expression and the predictive values of the parameters compared with other clinical factors. Among these parameters, TLG was the most relevant parameter that had a significant correlation with TS expression (ρ = 0.192, P = 0.008). A multivariable Cox proportional-hazards model revealed that high TLG was a significant independent predictor for treatment response (hazard ratio [HR]: 2.05; P = 0.027), progression-free survival (HR: 1.39; P = 0.043), and overall survival (HR: 1.65; P = 0.035) with other factors. In patients with advanced non-squamous NSCLC, tumor TLG on pretreatment PET/CT scan has predictive and prognostic value.

Comparison of the diagnostic performance of 18F-fluorothymidine versus 18F-fluorodeoxyglucose positron emission tomography on pulmonary lesions: A meta analysis

A pulmonary lesion is an extremely common and clinically challenging disorder worldwide, and an accurate diagnosis of lung cancer is crucial for early treatment and management. The aim of the present study was to perform a comprehensive meta analysis to compare the diagnostic performance of ¹⁸F-fluorothymidine (¹⁸F-FLT) positron emission tomography (PET) with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) PET in evaluating patients with pulmonary lesions. Relevant studies were identified using the PubMed, EMBASE and Cochrane library databases. The pooled estimated sensitivity, specificity, positive-likelihood ratio, negative-likelihood ratio, and diagnostic odds ratio (DOR) for ¹⁸F-FLT PET versus ¹⁸F-FDG PET were calculated as the main outcome measures. Summary receiver operating characteristic curves were also constructed by Meta-Disk 1.4 software using a Mose's constant of linear model. The meta analysis showed that ¹⁸F-FLT PET had a higher specificity (0.70; 95% CI, 0.61-0.77), but lower sensitivity (0.81; 95% CI, 0.74-0.87) compared to ¹⁸F-FDG PET (0.50; 95% CI, 0.41-0.58 for specificity; 0.92; 95% CI 0.86-0.95 for sensitivity). For DOR, ¹⁸F-FLT PET (12.58; 95% CI, 6.81-23.24) was higher compared to ¹⁸F-FDG PET (10.72; 95% CI, 5.51-20.87). The area under the curve was 0.8592 and 0.9240 for ¹⁸F-FLT PET and ¹⁸F-FDG PET, respectively (Z=0.976, P>0.05). In conclusion, ¹⁸F-FLT PET and ¹⁸F-FDG PET had good diagnostic performance for the overall assessment of pulmonary lesions, and ¹⁸F-FLT PET had a higher specificity compared to ¹⁸F-FDG PET, but was less sensitive than ¹⁸F-FDG PET. Therefore, ¹⁸F-FLT and ¹⁸F-FDG together could add diagnostic confidence for pulmonary lesions.