title: Serial 2-[18F] fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) to monitor treatment of bone-dominant metastatic breast cancer predicts time to progression (TTP).
abstract: BACKGROUND
  The response of bone-dominant (BD) breast cancer to therapy is difficult to assess by conventional imaging. Our preliminary studies have shown that quantitative serial 2-[(18)F] fluoro-2-deoxy-D: -glucose positron emission tomography (FDG PET) correlates with therapeutic response of BD breast cancer, but the relationship to long-term outcome measures is unknown. Our goal was to evaluate the prognostic power of serial FDG PET in BD breast cancer patients undergoing treatment.
  
  
  METHODS
  We reviewed medical records of 405 consecutive breast cancer patients referred for FDG PET. Of these, 28 demonstrated metastatic BD breast cancer, were undergoing treatment, had at least 2 serial PET scans, and had abnormal FDG uptake on the first scan. Standardized uptake value (SUV) for the most conspicuous bone lesion at the initial scan, absolute change in SUV over an interval of 1-17 months, and percent change in SUV were considered as predictors of time-to-progression (TTP) and time to skeletal-related event (t-SRE).
  
  
  RESULTS
  Using proportional hazards regression, smaller percentage decreases in SUV (or increases in SUV) were associated with a shorter TTP (P < 0.006). A patient with no change in SUV was twice as likely to progress compared to a patient with a 42% median decrease in SUV. A higher SUV on the initial FDG PET predicted a shorter t-SRE (hazard ratio = 1.30, P < 0.02).
  
  
  CONCLUSIONS
  Changes in serial FDG PET may predict TTP in BD metastatic breast cancer patients. However, larger prospective trials are needed to validate changes in FDG PET as a surrogate endpoint for treatment response.
authors.affiliation: Division of Medical Oncology, University of Washington School of Medicine, Seattle Cancer Care Alliance, 825 Eastlake Avenue E., G3-200, Seattle, WA 98109, USA. jspecht@u.washington.edu
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Specht
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Tam
authors.forename: Brenda F
authors.initials: BF
authors.lastname: Kurland
authors.forename: Julie R
authors.initials: JR
authors.lastname: Gralow
authors.forename: Robert B
authors.initials: RB
authors.lastname: Livingston
authors.forename: Hannah M
authors.initials: HM
authors.lastname: Linden
authors.forename: Georgiana K
authors.initials: GK
authors.lastname: Ellis
authors.forename: Erin K
authors.initials: EK
authors.lastname: Schubert
authors.forename: Lisa K
authors.initials: LK
authors.lastname: Dunnwald
authors.forename: David A
authors.initials: DA
authors.lastname: Mankoff
mesh_terms: D000328:Adult; D000368:Aged; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000556:secondary; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000494:pharmacology*; D006801:Humans; D008875:Middle Aged; D009362:Neoplasm Metastasis; D049268:Positron-Emission Tomography / Q000379:methods*; D016016:Proportional Hazards Models; D019275:Radiopharmaceuticals / Q000494:pharmacology*; D012189:Retrospective Studies
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18