title: Assessment of early response to imatinib 800 mg after 400 mg progression by ¹⁸F-fluorodeoxyglucose PET in patients with metastatic gastrointestinal stromal tumors.
abstract: BACKGROUND
  Imatinib is the standard first-line therapy for advanced gastrointestinal stromal tumor. (18)F-fluorodeoxyglucose PET computed tomography (FDG PET/CT) shows a faster response than computed tomography in nonpretreated patients.
  
  
  METHODS
  After disease progression on imatinib 400 mg, 16 patients were exposed to 800 mg. Tumor response was evaluated by FDG PET/CT on days 7 and 37. Primary objective was to correlate early metabolic response (EMR) with progression-free survival (PFS).
  
  
  RESULTS
  EMR by FDG PET/CT scan was not predictive of PFS. Median PFS in these patients was 3 months. Overall survival was influenced by gastric primary site (p = 0.05).
  
  
  CONCLUSIONS
  The assessment of EMR by FDG PET/CT in patients with advanced gastrointestinal stromal tumor exposed to imatinib 800 mg was not predictive of PFS or overall survival.
authors.affiliation: Grupo Argentino de Tumores Estromales Digestivos (GATE-D), Buenos Aires 1426, Argentina.
authors.forename: Matías
authors.initials: M
authors.lastname: Chacón
authors.forename: Martín
authors.initials: M
authors.lastname: Eleta
authors.forename: Adriel Rodríguez
authors.initials: AR
authors.lastname: Espindola
authors.forename: Enrique
authors.initials: E
authors.lastname: Roca
authors.forename: Guillermo
authors.initials: G
authors.lastname: Méndez
authors.forename: Sandra
authors.initials: S
authors.lastname: Rojo
authors.forename: Carmen
authors.initials: C
authors.lastname: Pupareli
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D005260:Female; D019788:Fluorodeoxyglucose F18; D005770:Gastrointestinal Neoplasms / Q000175:diagnosis* / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D046152:Gastrointestinal Stromal Tumors / Q000175:diagnosis* / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D000068877:Imatinib Mesylate / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D047428:Protein Kinase Inhibitors / Q000008:administration & dosage; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D047428:Protein Kinase Inhibitors; D019788:Fluorodeoxyglucose F18; D000068877:Imatinib Mesylate
keywords: FDG; GIST; PET; assessment; early; imatinib 800 mg; metabolic