title: Metabolic imaging metrics correlate with survival in early stage lung cancer treated with stereotactic ablative radiotherapy.
abstract: OBJECTIVE
  To test whether (18)F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) imaging metrics correlate with outcomes in patients with stage I non-small cell lung cancer (NSCLC) treated with stereotactic ablative radiotherapy (SABR).
  
  
  METHODS
  Fifty-four patients with stage I NSCLC underwent pre-SABR PET at simulation and/or post-SABR PET within 6 months. We analyzed maximum standardized uptake value (SUV(max)) and metabolic tumor volume defined using several thresholds (MTV50%, or MTV2, 4, 7, and 10). Endpoints included primary tumor control (PTC), progression-free survival (PFS), overall survival (OS) and cancer-specific survival (CSS). We performed Kaplan-Meier, competing risk, and Cox proportional hazards survival analyses.
  
  
  RESULTS
  Patients received 25-60 Gy in 1 to 5 fractions. Median follow-up time was 13.2 months. The 1-year estimated PTC, PFS, OS and CSS were 100, 83, 87 and 94%, respectively. Pre-treatment SUV(max) (p=0.014), MTV(7) (p=0.0077), and MTV(10) (p=0.0039) correlated significantly with OS. In the low-MTV(7)vs. high-MTV(7) sub-groups, 1-year estimated OS was 100 vs. 78% (p=0.0077) and CSS was 100 vs. 88% (p=0.082).
  
  
  CONCLUSIONS
  In this hypothesis-generating study we identified multiple pre-treatment PET-CT metrics as potential predictors of OS and CSS in patients with NSCLC treated with SABR. These could aid risk-stratification and treatment individualization if validated prospectively.
authors.affiliation: Department of Radiation Oncology, School of Medicine, Stanford University, Stanford, CA 94305, USA.
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Abelson
authors.forename: James D
authors.initials: JD
authors.lastname: Murphy
authors.forename: Nicholas
authors.initials: N
authors.lastname: Trakul
authors.forename: Jose G
authors.initials: JG
authors.lastname: Bazan
authors.forename: Peter G
authors.initials: PG
authors.lastname: Maxim
authors.forename: Edward E
authors.initials: EE
authors.lastname: Graves
authors.forename: Andrew
authors.initials: A
authors.lastname: Quon
authors.forename: Quynh-Thu
authors.initials: QT
authors.lastname: Le
authors.forename: Maximilian
authors.initials: M
authors.lastname: Diehn
authors.forename: Billy W
authors.initials: BW
authors.lastname: Loo
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D016016:Proportional Hazards Models; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D016634:Radiosurgery; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18