title: FDG-PET parameters predicting mediastinal malignancy in lung cancer.
abstract: Staging of mediastinal lymph nodes in non-small cell lung cancer (NSCLC) is mandatory. The maximum Standard Uptake Value (SUVmax) obtained using F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) is the best non-invasive technique available for this evaluation, but its performance varies from center to center. The aim of the present study was to identify FDG-PET predictors of mediastinal malignancy that are able to minimize intercenter variability and improve the selection of subsequent staging procedures.
  
  
  
  A multicenter study of NSCLC patients staged through FDG-PET and endobronchial ultrasonography with needle aspiration (EBUS-NA) was performed using therapeutic surgery with systematic nodal dissection as gold standard. Intercenter variability and predictive power for mediastinal malignancy of different FDG-PET measures were assessed, as well as the role of these measures for selecting additional staging procedures.
  
  
  
  One hundred and twenty-one NSCLC patients, of whom 94 (72%) had ≥1 hypermetabolic spots in the mediastinum, were included in the study. Mean SUVmax of the primary tumor was 12.3 (SD 6.3), and median SUVmax of the highest hypermetabolic spots in the mediastinum was 3.9 (IQR 2.4-7). Variability of FDG-PET measures between hospitals was statistically significant (p = 0.016 and p < 0.001 respectively), but lost significance when SUVmax in the mediastinum was expressed as a ratio or a subtraction from the primary tumor (SUVmax mediastinum/tumor, p = 0.083; and SUVmax mediastinum - tumor, p = 0.428 respectively). SUVmax mediastinum/tumor showed higher accuracy in the ROC analysis (AUC 0.77 CI 0.68-0.85, p < 0.001), and showed predictive power for mediastinal malignancy when using a 0.4 cutoff (OR 6.62, 95%CI 2.98-14.69). Sensitivities and negative predictive values of clinical staging through EBUS-NA attained values ranging between 57% and 92% after FDG-PET, which improved with additional techniques when the tumor had a diameter >3 cm and/or a SUVmax mediastinum/tumor ratio >0.4.
  
  
  
  The SUVmax mediastinum/tumor ratio is a good predictor of regional tumor extension in NSCLC. This measure is not influenced by intercenter variability and has an accuracy of over 70% for the identification of malignancy when using a 0.4 cutoff.
authors.affiliation: Hospital Universitari Parc Taulí, Sabadell, Spain. mserra.ebre.ics@gencat.cat.|Departament de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain. mserra.ebre.ics@gencat.cat.
authors.forename: M
authors.initials: M
authors.lastname: Serra Fortuny
authors.affiliation: Hospital Universitari Parc Taulí, Sabadell, Spain.|Ciber de Enfermedades Respiratorias - Ciberes, Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Gallego
authors.affiliation: Hospital Universitari Parc Taulí, Sabadell, Spain.
authors.forename: Ll
authors.initials: L
authors.lastname: Berna
authors.affiliation: Hospital Universitari Parc Taulí, Sabadell, Spain.|Health Services Research on Chronic Diseases Network- REDISSEC, Madrid, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Montón
authors.affiliation: Hospital Universitari Parc Taulí, Sabadell, Spain.|Ciber de Enfermedades Respiratorias - Ciberes, Madrid, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Vigil
authors.affiliation: Hospital Universitari Parc Taulí, Sabadell, Spain.
authors.forename: M J
authors.initials: MJ
authors.lastname: Masdeu
authors.affiliation: Complexo Hospitalario Universitario de Vigo, Vigo, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Fernández-Villar
authors.affiliation: Complexo Hospitalario Universitario de Vigo, Vigo, Spain.
authors.forename: M I
authors.initials: MI
authors.lastname: Botana
authors.affiliation: Complejo Asistencial de Salamanca, Salamanca, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Cordovilla
authors.affiliation: Ciber de Enfermedades Respiratorias - Ciberes, Madrid, Spain.|Hospital Universitario 12 de Octubre, Madrid, Spain.
authors.forename: R
authors.initials: R
authors.lastname: García-Luján
authors.affiliation: Hospital Universitari La Fe, Valencia, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Cases
authors.affiliation: Hospital Universitari Parc Taulí, Sabadell, Spain.|Departament de Medicina, Universitat Autònoma de Barcelona, Bellaterra, Spain.|Ciber de Enfermedades Respiratorias - Ciberes, Madrid, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Monsó
mesh_terms: D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology*; D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D016015:Logistic Models; D008175:Lung Neoplasms / Q000473:pathology*; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008479:Mediastinal Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D008482:Mediastinum / Q000000981:diagnostic imaging / Q000473:pathology; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D012372:ROC Curve; D013030:Spain
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: EBUS-NA; Endobronchial ultrasonography with needle aspiration; F-18 fluorodeoxyglucose positron emission tomography; FDG-PET; Lung cancer; NSCLC