title: Inter- and intra-observer variability in biopsy of bone and soft tissue sarcomas.
abstract: OBJECTIVE
  The aim of this study was to analyze the inter- and intra-observer variability regarding biopsy technique in bone and soft tissue sarcoma based on magnetic resonance imaging (MRI).
  
  
  METHODS
  Thirty-seven MRI scans of bone and soft tissue sarcomas treated in our clinic were randomly selected. Six observers with three different expertise levels were assigned to analyze the scans for suspected entity and preferred biopsy technique at 2 time points with a delay of 8 weeks.
  
  
  RESULTS
  The differentiation between bone and soft tissue sarcomas in MRI seemed closely related to the observer's level of experience. Regarding biopsy technique, no inter-observer accordance could be identified in either group.
  
  
  CONCLUSIONS
  We observed an association of inter- and intra-observer agreement regarding suspected tumor entity and the observer's level of experience. The decision for either biopsy technique showed a low inter-observer but high intra-observer variability. These findings suggest that the decision for incisional or core needle biopsy is, even in the expert group, frequently based on personal predilection.
authors: Department of Orthopedic Surgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany muehlhofer@lrz.tu-muenchen.de.
authors: Heinrich M L
authors: HM
authors: Mühlhofer
authors: Department of Orthopedic Surgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors: Ulrich
authors: U
authors: Lenze
authors: Department of Orthopedic Surgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors: Florian
authors: F
authors: Lenze
authors: Institute of Medical Statistics and Epidemiology, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors: Ina-Christine
authors: IC
authors: Rondak
authors: Department of Orthopedic Surgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors: Johannes
authors: J
authors: Schauwecker
authors: Department of Orthopedic Surgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors: Hans
authors: H
authors: Rechl
authors: Department of Orthopedic Surgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors: Ruediger
authors: R
authors: Von Eisenhart-Rothe
authors: Department of Orthopedic Surgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
authors: Florian
authors: F
authors: Pohlig
mesh_terms: D001706:Biopsy; D001859:Bone Neoplasms / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D015588:Observer Variation; D012516:Osteosarcoma / Q000473:pathology*; D012509:Sarcoma / Q000473:pathology*
keywords: Biopsy; core needle biopsy; open biopsy; sarcoma