title: High prognostic value of 18F-FDG PET for metastatic gastroenteropancreatic neuroendocrine tumors: a long-term evaluation.
abstract: This study aimed to evaluate the long-term prognostic usefulness of (18)F-FDG PET for patients with metastatic gastroenteropancreatic neuroendocrine tumors (GEPNETs).
  
  
  METHODS
  Thirty-eight patients with metastatic GEPNETs were prospectively enrolled. Initial check-up comprised CT scan, (111)In-pentetreotide scintigraphy (SRS), and (18)F-FDG PET. Only (18)F-FDG PET-positive lesions with a maximum standardized uptake value (SUVmax) greater than 4.5 or an SUV ratio (SUVmax tumor to SUVmax nontumoral liver tissue, or T/NT ratio) of 2.5 or greater were considered positive for prognosis-that is, indicating a poor prognosis. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. Factors associated with survival were assessed with univariate and multivariate analyses, using the Cox regression model.
  
  
  RESULTS
  Median PFS and OS were significantly higher for patients with a negative (18)F-FDG PET finding, with an OS of 119.5 mo (95% confidence interval [CI], 72-∞), than for patients with a positive (18)F-FDG PET finding (only 15 mo [95% CI, 4-27]) (P < 10(-3)). Median PFS and OS were significantly higher for the patient group that had a positive SRS than the group with a negative SRS (P = 0.0002). For patients with a positive SRS, PFS and OS were significantly shorter when the (18)F-FDG PET finding was positive: 19.5 mo (95% CI, 4-37) for PFS and 119.5 mo (95% CI, 81-∞) for OS (P < 10(-3)). In the patient group with a low-grade GEPNET and a positive SRS, PFS and OS were also significantly lower for patients with a positive (18)F-FDG PET. At 48-mo follow-up, 100% of patients who had a positive (18)F-FDG PET for disease progression (of which 47% were also SRS-positive) were deceased, and 87% of patients with a negative (18)F-FDG PET were alive (P < 0.0001). The T/NT ratio was the only parameter associated with OS on multivariate analysis.
  
  
  CONCLUSIONS
  Overall, (18)F-FDG PET appears to be of major importance in the prognostic evaluation of metastatic GEPNET. A positive (18)F-FDG PET with an SUV ratio (T/NT) of 2.5 or greater was a poor prognostic factor, with a 4-y survival rate of 0%. A positive SRS does not eliminate the need for performing (18)F-FDG PET, which is of greater prognostic utility.
authors.affiliation: Department of Nuclear Medicine, Cancer Institute Eugène Marquis, Rennes, France.
authors.forename: Haïfa
authors.initials: H
authors.lastname: Bahri
authors.affiliation: Department of Nuclear Medicine, Cancer Institute Eugène Marquis, Rennes, France Inserm, UMR991, Liver Metabolisms and Cancer, Rennes, France University of Rennes 1, Rennes, France.
authors.forename: Lenoir
authors.initials: L
authors.lastname: Laurence
authors.affiliation: Inserm, UMR991, Liver Metabolisms and Cancer, Rennes, France University of Rennes 1, Rennes, France Department of Medical Oncology, Cancer Institute Eugène Marquis, Rennes, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Edeline
authors.affiliation: Department of Nuclear Medicine, Cancer Institute Eugène Marquis, Rennes, France.
authors.forename: Houda
authors.initials: H
authors.lastname: Leghzali
authors.affiliation: Department of Nuclear Medicine, Cancer Institute Eugène Marquis, Rennes, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Devillers
authors.affiliation: Department of Medical Oncology, Comprehensive Cancer Center, Institute Paoli Calmette, Marseille, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Raoul
authors.affiliation: Department of Medical Computing, CHU Pontchaillou, Rennes, France; and.
authors.forename: Marc
authors.initials: M
authors.lastname: Cuggia
authors.affiliation: Department of Medical Informations, Cancer Institute Eugène Marquis, Rennes, France.
authors.forename: Habiba
authors.initials: H
authors.lastname: Mesbah
authors.affiliation: Inserm, UMR991, Liver Metabolisms and Cancer, Rennes, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Clement
authors.affiliation: Inserm, UMR991, Liver Metabolisms and Cancer, Rennes, France Department of Medical Oncology, Cancer Institute Eugène Marquis, Rennes, France.
authors.forename: Eveline
authors.initials: E
authors.lastname: Boucher
authors.affiliation: Department of Nuclear Medicine, Cancer Institute Eugène Marquis, Rennes, France Inserm, UMR991, Liver Metabolisms and Cancer, Rennes, France University of Rennes 1, Rennes, France e.garin@rennes.unicancer.fr.
authors.forename: Etienne
authors.initials: E
authors.lastname: Garin
mesh_terms: D000368:Aged; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007414:Intestinal Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009362:Neoplasm Metastasis; D018358:Neuroendocrine Tumors / Q000175:diagnosis / Q000000981:diagnostic imaging*; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography; D011336:Probability; D011379:Prognosis; D016016:Proportional Hazards Models; D012372:ROC Curve; D011877:Radionuclide Imaging; D013274:Stomach Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging*; D016896:Treatment Outcome
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: FDG; PET; neuroendocrine; prognosis