title: Role of 18F-fluorodeoxyglucose positron emission tomography in predicting epidermal growth factor receptor mutations in non-small cell lung cancer.
abstract: OBJECTIVE
  To compare (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) and computed tomography (CT) imaging characteristics in non-small cell lung cancer (NSCLC) with or without epidermal growth factor receptor (EGFR) mutations.
  
  
  METHODS
  We retrospectively identified NSCLC patients who underwent EGFR mutation testing and pretreatment FDG-PET and CT scans. The maximum standard uptake value (SUV(max)) of the primary tumor and any metastases was measured and normalized to the SUV of blood in the pulmonary artery. We compared normalized SUV(max) values between EGFR-mutant and wild-type patients and modeled radiographic and clinical predictors of EGFR mutation status. Receiver operator characteristic (ROC) curves were used to identify potential SUV cutoffs predictive of genotype.
  
  
  RESULTS
  We included 100 patients (24 EGFR-mutant and 76 wild-type). There was a trend for higher normalized SUV(max) in the primary tumors among patients with EGFR-wild-type versus mutant (median, 3.4; range, 0.6-12.8; versus median, 2.9; range, 0.4-5.0; p = .09). Normalized SUV(max) of nodal and distant metastases, and CT characteristics were not associated with genotype. On multivariate analysis, low normalized SUV(max) of the primary tumor was predictive for EGFR mutation (odds ratio, 0.72; 95% confidence interval, 0.53-0.98; p = .034). ROC curve analyses yielded an area under the curve of 0.62, and identified a potential cutoff of ≥ 5.0 to distinguish wild-type from mutant tumors.
  
  
  CONCLUSIONS
  In this retrospective study, high FDG avidity (normalized SUV(max) ≥ 5) correlated with EGFR-wild-type genotype. Although genotyping remains the gold standard, further work to validate FDG-PET as a surrogate for tumor genotype may provide useful information in patients without available tumor tissue.
authors.affiliation: Harvard Radiation Oncology Program, Boston, MA, USA.
authors.forename: Raymond H
authors.initials: RH
authors.lastname: Mak
authors.forename: Subba R
authors.initials: SR
authors.lastname: Digumarthy
authors.forename: Alona
authors.initials: A
authors.lastname: Muzikansky
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Engelman
authors.forename: Jo-Anne O
authors.initials: JA
authors.lastname: Shepard
authors.forename: Noah C
authors.initials: NC
authors.lastname: Choi
authors.forename: Lecia V
authors.initials: LV
authors.lastname: Sequist
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D015331:Cohort Studies; D066246:ErbB Receptors / Q000235:genetics*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000201:enzymology / Q000235:genetics / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging; D017354:Point Mutation; D049268:Positron-Emission Tomography / Q000379:methods; D012372:ROC Curve; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D066246:ErbB Receptors