title: Variations in apparent diffusion coefficient values following chemotherapy in pediatric neuroblastoma.
abstract: OBJECTIVE
  In children the assessment of solid tumors' response to chemotherapy is based primarily on size reduction, which can be unreliable and a late marker, in the presence of necrosis. We aimed to establish whether apparent diffusion coefficient (ADC) values of childhood neuroblastomas show proportional changes in relation to chemotherapy response.
  
  
  METHODS
  We evaluated 15 pediatric patients with abdominopelvic neuroblastomas, who had undergone MRI before and after chemotherapy. Two radiologists retrospectively analyzed all images by drawing a round uniform region-of-interest in the solid/contrast-enhancing portion of the lesions in consensus. The ADC values from pre- and postchemotherapy images were compared.
  
  
  RESULTS
  Postchemotherapy ADC values were significantly higher than those obtained before treatment (P < 0.05, for minimum, maximum, and median ADC values).
  
  
  CONCLUSIONS
  Our results support diffusion-weighted MRI as a promising noninvasive biomarker of therapeutic responses. To the best of our knowledge, this is the first report to compare diffusion- weighted imaging findings before and after chemotherapy in childhood neuroblastic tumors.
authors.affiliation: Department of Radiology, Baskent University School of Medicine, Adana, Turkey. drsenaydemir@hotmail.com.
authors.forename: Senay
authors.initials: S
authors.lastname: Demir
authors.forename: Naime
authors.initials: N
authors.lastname: Altinkaya
authors.forename: Nazim Emrah
authors.initials: NE
authors.lastname: Kocer
authors.forename: Ayse
authors.initials: A
authors.lastname: Erbay
authors.forename: Pelin
authors.initials: P
authors.lastname: Oguzkurt
mesh_terms: D000008:Abdominal Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000473:pathology; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009447:Neuroblastoma / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000473:pathology; D010386:Pelvic Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000473:pathology; D012189:Retrospective Studies; D016896:Treatment Outcome; D047368:Tumor Burden
chemical_list: D000970:Antineoplastic Agents