title: Limited predictive value of FDG-PET for response assessment in the preoperative treatment of esophageal cancer: results of a prospective multi-center trial (SAKK 75/02).
abstract: BACKGROUND
  Only responding patients benefit from preoperative therapy for locally advanced esophageal carcinoma. Early detection of non-responders may avoid futile treatment and delayed surgery.
  
  
  METHODS
  In a multi-center phase ll trial, patients with resectable, locally advanced esophageal carcinoma were treated with 2 cycles of induction chemotherapy followed by chemoradiotherapy (CRT) and surgery. Positron emission tomography with 2[fluorine-18]fluoro-2-deoxy-d-glucose (FDG-PET) was performed at baseline and after induction chemotherapy. The metabolic response was correlated with tumor regression grade (TRG). A decrease in FDG tumor uptake of less than 40% was prospectively hypothesized as a predictor for histopathological non-response (TRG > 2) after CRT.
  
  
  RESULTS
  45 patients were included. The median decrease in FDG tumor uptake after chemotherapy correlated well with TRG after completion of CRT (p = 0.021). For an individual patient, less than 40% decrease in FDG tumor uptake after induction chemotherapy predicted histopathological non-response after completion of CRT, with a sensitivity of 68% and a specificity of 52% (positive predictive value 58%, negative predictive value 63%).
  
  
  CONCLUSIONS
  Metabolic response correlated with histopathology after preoperative therapy. However, FDG-PET did not predict non-response after induction chemotherapy with sufficient clinical accuracy to justify withdrawal of subsequent CRT and selection of patients to proceed directly to surgery.
authors.affiliation: Department of Nuclear Medicine, Inselspital Bern, Switzerland. bernd.klaeser@insel.ch
authors.forename: Bernd
authors.initials: B
authors.lastname: Klaeser
authors.forename: Egbert
authors.initials: E
authors.lastname: Nitzsche
authors.forename: Jan C
authors.initials: JC
authors.lastname: Schuller
authors.forename: Dieter
authors.initials: D
authors.lastname: Köberle
authors.forename: Lucas
authors.initials: L
authors.lastname: Widmer
authors.forename: Sabine
authors.initials: S
authors.lastname: Balmer-Majno
authors.forename: Thomas
authors.initials: T
authors.lastname: Hany
authors.forename: Corinne
authors.initials: C
authors.lastname: Cescato-Wenger
authors.forename: Peter
authors.initials: P
authors.lastname: Brauchli
authors.forename: Michael
authors.initials: M
authors.lastname: Zünd
authors.forename: Bernhard C
authors.initials: BC
authors.lastname: Pestalozzi
authors.forename: Clemens
authors.initials: C
authors.lastname: Caspar
authors.forename: Susanne
authors.initials: S
authors.lastname: Albrecht
authors.forename: Roger
authors.initials: R
authors.lastname: von Moos
authors.forename: Thomas
authors.initials: T
authors.lastname: Ruhstaller
mesh_terms: D000328:Adult; D000368:Aged; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging* / Q000628:therapy*; D005260:Female; D019788:Fluorodeoxyglucose F18; D005858:Germany; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011300:Preoperative Care; D011379:Prognosis; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013557:Switzerland; D016896:Treatment Outcome
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18