title: Correlation of PET/CT findings and histopathology after neoadjuvant therapy in non-small cell lung cancer.
abstract: OBJECTIVE
  Prediction of histopathological response with PET/CT scans after neoadjuvant chemoradiotherapy is limited by confounding factors which have been evaluated in this analysis.
  
  
  METHODS
  (18)F-2-fluoro-2-deoxy-D-glucose (FDG)-PET/CT findings [standard uptake value (SUV), residual tumor volume] were correlated with histopathological parameters of the resection specimens (tumor cell density, necrosis, scar, macrophage infiltration) in patients with locally advanced non-small cell lung cancer (stage IIIA/IIIB) after neoadjuvant induction chemotherapy (platinum-based doublet) and concurrent chemoradiotherapy (cisplatin/vinorelbine/45 Gy).
  
  
  RESULTS
  Sixty patients [40 male/20 female, median age 56 years (34-78)] completed induction therapy, 46 patients (stage IIIA/IIIB: 16/30; squamous cell carcinoma 41%, adenocarcinoma 48%, large cell carcinoma 11%) were resected. Pathologic complete response of the primary tumor was observed in 19 patients (41%) with a broad range of SUV(mean) (0.4-9.8, mean 3.0) after neoadjuvant therapy. A high rate of histopathological complete remissions (44%) was observed in tumors with a postinduction SUV >2.5 and volumes larger than the median (7.9 cm(3)) before resection. SUV(mean) was positively correlated with the macrophage score (r = 0.39, p = 0.007) and tumor cell density (r = 0.32, p = 0.03).
  
  
  CONCLUSIONS
  These observations suggest that postinduction FDG uptake should be interpreted with caution in larger residual tumor volumes, since high SUV levels may be due to macrophage infiltration and not viable tumor tissue.
authors.affiliation: Department of Radiotherapy, University of Duisburg-Essen, Essen, Germany. christoph.poettgen@uk-essen.de
authors.forename: Christoph
authors.initials: C
authors.lastname: Poettgen
authors.forename: Dirk
authors.initials: D
authors.lastname: Theegarten
authors.forename: Wilfried
authors.initials: W
authors.lastname: Eberhardt
authors.forename: Sabine
authors.initials: S
authors.lastname: Levegruen
authors.forename: Thomas
authors.initials: T
authors.lastname: Gauler
authors.forename: Thomas
authors.initials: T
authors.lastname: Krbek
authors.forename: Georgios
authors.initials: G
authors.lastname: Stamatis
authors.forename: Helmut
authors.initials: H
authors.lastname: Teschler
authors.forename: Hilmar
authors.initials: H
authors.lastname: Kuehl
authors.forename: Andreas
authors.initials: A
authors.lastname: Bockisch
authors.forename: Martin
authors.initials: M
authors.lastname: Stuschke
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy; D002945:Cisplatin / Q000008:administration & dosage; D004334:Drug Administration Schedule; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed; D014747:Vinblastine / Q000008:administration & dosage / Q000031:analogs & derivatives; D000077235:Vinorelbine
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D014747:Vinblastine; D002945:Cisplatin; D000077235:Vinorelbine