title: F-18-FDG PET-CT in children and young adults with Ewing sarcoma diagnosed in Norway during 2005-2012: a national population-based study.
abstract: BACKGROUND
  To examine national imaging strategies regarding the use of F-18-FDG PET-CT in patients with Ewing sarcoma and study factors that might influence the use of PET-CT, such as tumour biology (Picci grade of operation specimen), clinical disease stage and age.
  
  
  METHODS
  We examined the medical records including pathology and imaging of all patients below 30 years diagnosed with Ewing sarcoma in Norway in 2005-2012.
  
  
  RESULTS
  Of 61 patients treated at one of the two national sarcoma treatment service centres (Oslo: 35, Bergen: 26), 29 patients had localized disease, 8 had tumour extending to organs nearby and 24 had metastases. Among 35 operated patients with neoadjuvant chemotherapy, 15 had Picci grades II and III (good responders) and 20 grade I (poor responders). We found a significant difference in the use of PET-CT (Oslo/Bergen 0·9 versus 2·0 scans per patient, P = 0·010) and in the use of MRI (Oslo/Bergen: eight versus 13, P = 0·006). No differences were proven for ultrasound, radiography, CT or skeletal scintigraphy. The number of PET-CTs was associated with clinical disease stage at diagnosis (P = 0·041) but not with Picci grade or age. The number of PET studies was not correlated to the number of MR studies.
  
  
  CONCLUSIONS
  The use of PET-CT in children and young adults diagnosed with Ewing sarcoma in Norway during 2005-2012 at the two national sarcoma treatment service centres differed significantly. The use of PET-CT imaging was related to the clinical disease stage at diagnosis but unrelated to patient age and tumour biology (Picci grade).
authors.affiliation: Centre for Nuclear Medicine and PET, Department of Radiology, Haukeland University Hospital, Bergen, Norway. boel.johnsen@helse-bergen.no.
authors.forename: Boel
authors.initials: B
authors.lastname: Johnsen
authors.affiliation: Department of Oncology, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway.
authors.forename: Kjetil
authors.initials: K
authors.lastname: Boye
authors.affiliation: Pediatric Section, Department of Radiology, Haukeland University Hospital, Bergen, Norway.|Department of Clinical Medicine, University of Bergen, Bergen, Norway.
authors.forename: Karen
authors.initials: K
authors.lastname: Rosendahl
authors.affiliation: Centre for Nuclear Medicine and PET, Department of Radiology, Haukeland University Hospital, Bergen, Norway.|Department of Clinical Medicine, University of Bergen, Bergen, Norway.
authors.forename: Martin
authors.initials: M
authors.lastname: Biermann
authors.affiliation: Department of Clinical Medicine, University of Bergen, Bergen, Norway.|Ortopedic Section, Department of Surgery, Haukeland University Hospital, Bergen, Norway.
authors.forename: Clement
authors.initials: C
authors.lastname: Trovik
authors.affiliation: Pediatric Section, Department of Radiology, Haukeland University Hospital, Bergen, Norway.|Department of Clinical Medicine, University of Bergen, Bergen, Norway.
authors.forename: Stein Magnus
authors.initials: SM
authors.lastname: Aukland
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000628:therapy; D002648:Child; D002675:Child, Preschool; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage*; D054625:Healthcare Disparities; D006801:Humans; D008297:Male; D008499:Medical Records; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D009664:Norway; D000072078:Positron Emission Tomography Computed Tomography / Q000706:statistics & numerical data / Q000639:trends*; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data / Q000639:trends*; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals / Q000008:administration & dosage*; D012189:Retrospective Studies; D012512:Sarcoma, Ewing / Q000000981:diagnostic imaging* / Q000556:secondary / Q000628:therapy; D013997:Time Factors; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: Ewing sarcoma; magnetic resonance imaging; nuclear medicine imaging; positron-emission tomography; radiologic imaging; skeletal scintigraphy