Value of metabolic parameters in distinguishing primary mediastinal lymphomas from thymic epithelial tumors

Multiparameter diagnostic model based on 18F-FDG PET and clinical characteristics can differentiate thymic epithelial tumors from thymic lymphomas

“…According to our investigation, few previous studies investigated the differential diagnosis of TETs and thymic lymphoma by using 18 F-FDG PET metabolic parameters. Zhu et al applied metabolic parameters in differential diagnosis of 71 patients with primary mediastinal lymphomas (PMLs) and 65 patients with TETs [ 23 ]. Patients with PMLs had higher SUVmean, SUVmax, TLG, and MTV values than patients with TETs.…”

“…Due to the differences of age and symptoms between TETs and thymic lymphoma, as well as the good diagnostic ability of metabolic parameters, we combined age, symptoms and SUVR to form a diagnostic model. Previous study combining age and SUVmean demonstrated the ability in the differential diagnosis of TETs and thymic lymphomas, with high sensitivity (83.1%) and specificity (88.7%) [ 23 ]. In our study, through NRI, IDI and Delong test, the application of model 3 could significantly improve the differential diagnostic ability compared to SUVR.…”

“…Although several studies have described the 18 F-FDG PET or PET/CT values in the diagnosis of mediastinal tumors, to our knowledge, most studies have analyzed some types of these tumors [ 17 , 20 – 22 ],and there were few systematic descriptions of thymic tumors and comparisons between TETs and thymic lymphomas [ 23 ]. Most studies only rely on PET metabolic parameters for analysis, ignoring the differences in patients’ baseline characteristics and clinical symptoms.…”

Relationship between 18F-FDG PET/CT Semi-Quantitative Parameters and International Association for the Study of Lung Cancer, American Thoracic Society/European Respiratory Society Classification in Lung Adenocarcinomas

“…However, the results were inconclusive. Some of the reasons may be the fact that the single-voxel-based SUVmax measures demonstrate the tumor pixel with the highest uptake rather than the whole tumor [ 11 12 13 ]. Alternative quantitative metrics that consider not only SUVmax but also tracer uptake throughout the entire lesion have been proposed, such as metabolic tumor volume (MTV), which is defined as the total number of voxels within a volume of interest that have uptake above a predetermined SUV threshold, and total lesion glycolysis (TLG), calculated as MTV × SUVmean.…”

“…Alternative quantitative metrics that consider not only SUVmax but also tracer uptake throughout the entire lesion have been proposed, such as metabolic tumor volume (MTV), which is defined as the total number of voxels within a volume of interest that have uptake above a predetermined SUV threshold, and total lesion glycolysis (TLG), calculated as MTV × SUVmean. Recent studies have identified volumetric parameters (MTV and TLG) as significant independent variables in predicting histological subtypes of esophageal cancer and other tumors [ 13 14 15 ]. However, MTV or TLG do not consider background activity; therefore, they are not accurate enough to delineate the boundaries of spatial heterogeneity intratumor or metabolically active tumor volume, especially for ground-glass nodules (GGN).…”