title: Whole-body MR imaging for staging of malignant tumors in pediatric patients: results of the American College of Radiology Imaging Network 6660 Trial.
abstract: OBJECTIVE
  To compare whole-body magnetic resonance (MR) imaging with conventional imaging for detection of distant metastases in pediatric patients with common malignant tumors.
  
  
  METHODS
  This institutional review board-approved, HIPAA-compliant, multicenter prospective cohort study included 188 patients (109 male, 79 female; mean age, 10.2 years; range, < 1 to 21 years) with newly diagnosed lymphoma, neuroblastoma, or soft-tissue sarcoma. Informed consent was obtained and all patients underwent noncontrast material-enhanced whole-body MR imaging and standard-practice conventional imaging. All images were reviewed centrally by 10 pairs of readers. An independent panel verified the presence or absence of distant metastases. Detection of metastasis with whole-body MR and conventional imaging was quantified by using the area under the receiver operating characteristic curve (AUC). The effects of tumor subtype, patient age, and distant skeletal and pulmonary disease on diagnostic accuracy were also analyzed.
  
  
  RESULTS
  Of the 134 eligible patients, 66 (33 positive and 33 negative for metastasis) were selected for image review and analysis. Whole-body MR imaging did not meet the noninferiority criterion for accuracy when compared with conventional imaging for detection of metastasis (difference between average AUCs was -0.03 [95% confidence interval: -0.10, 0.04]); however, the average AUC for solid tumors was significantly higher than that for lymphomas (P = .006). More skeletal metastases were detected by using whole-body MR imaging than by using conventional imaging (P = .03), but fewer lung metastases were detected (P < .001). Patient age did not affect accuracy.
  
  
  CONCLUSIONS
  The noninferior accuracy for diagnosis of distant metastasis in patients with common pediatric tumors was not established for the use of whole-body MR imaging compared with conventional methods. However, improved accuracy was seen with whole-body MR imaging in patients with nonlymphomatous tumors.
authors.affiliation: Mallinckrodt Institute of Radiology and Siteman Cancer Center, Washington University School of Medicine, 510 S Kingshighway Blvd, St Louis, MO 63110, USA. siegelm@mir.wustl.edu
authors.forename: Marilyn J
authors.initials: MJ
authors.lastname: Siegel
authors.forename: Suddhasatta
authors.initials: S
authors.lastname: Acharyya
authors.forename: Frederic A
authors.initials: FA
authors.lastname: Hoffer
authors.forename: J Brad
authors.initials: JB
authors.lastname: Wyly
authors.forename: Alison M
authors.initials: AM
authors.lastname: Friedmann
authors.forename: Bradley S
authors.initials: BS
authors.lastname: Snyder
authors.forename: Paul S
authors.initials: PS
authors.lastname: Babyn
authors.forename: Geetika
authors.initials: G
authors.lastname: Khanna
authors.forename: Barry A
authors.initials: BA
authors.lastname: Siegel
mesh_terms: D019540:Area Under Curve; D001706:Biopsy; D002648:Child; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D009369:Neoplasms / Q000473:pathology*; D011446:Prospective Studies; D012372:ROC Curve; D014481:United States; D051598:Whole Body Imaging