title: Local Staging of Soft-Tissue Sarcoma: Emphasis on Assessment of Neurovascular Encasement-Value of MR Imaging in 174 Confirmed Cases.
abstract: OBJECTIVE
  To evaluate utility of magnetic resonance (MR) imaging in local staging of soft-tissue sarcoma, with an emphasis on assessment of neurovascular encasement.
  
  
  METHODS
  Institutional review board approval was obtained; informed consent requirement was waived. Preoperative MR images in 174 patients with soft-tissue sarcoma were analyzed by two readers. Tumor staging according to the American Joint Committee on Cancer/Union International Contre le Cancer and Enneking staging systems and analysis of osseous and articular invasion were performed. To assess neurovascular encasement, contact between tumor and arteries, between tumor and veins, and between tumor and nerves was classified (no contact, contact ≤90°, 91°-180°, 181°-270°, >271°). Interobserver agreement was determined; imaging findings were correlated with intraoperative findings and/or histopathologic findings (Pearson correlation coefficient [r] and Cohen κ coefficient).
  
  
  RESULTS
  Intraoperative evaluation and/or histopathologic evaluation confirmed osseous, articular, and neurovascular invasion in 8.6%, 2.9%, and 25.3% of patients. Interobserver agreement was excellent for tumor staging (American Joint Committee on Cancer/Union International Contre le Cancer staging, κ = 0.811; Enneking staging, κ = 0.943) and osseous invasion (κ = 1.000). It was substantial for articular invasion (κ = 0.794). Sensitivity and specificity for osseous invasion were 100% and 98.7%, respectively (both readers). For articular invasion, sensitivity was 80% (both readers); specificities were 100% and 98.8% for readers 1 and 2, respectively. Interobserver agreement in quantifying contact between tumor and vessels and between tumor and nerves was excellent for arteries, veins, and nerves (κ = 0.845, 0.892, 0.893, respectively). Receiver operating characteristic analysis revealed optimal threshold of greater than 180° for prediction of arterial and venous encasement (both readers). For neural encasement, optimal threshold was greater than 180° (reader 1) and greater than 270° (reader 2). Sensitivities in diagnosing encasement for arteries, veins, and nerves were 84.6%, 84.6%, and 77.8% (reader 1) and 84.6%, 84.6%, and 72.2% (reader 2). Specificities for encasement of arteries, veins, and nerves, respectively, were 97.5%, 97.5%, and 93.2% (reader 1) and 93.8%, 94.7%, 97.3% (reader 2).
  
  
  CONCLUSIONS
  MR imaging allows reliable and accurate local staging of soft-tissue sarcoma. Encasement of arteries, veins, and nerves should be diagnosed, if the contact between tumor and vascular or neural circumference exceeds 180°.
authors.affiliation: From the Department of Radiology (K.H., J.R., T.B., E.J.R., K.W.), Department of Orthopedic Surgery (H.R., R.v.E., R.G.), Institute of Pathology (K.S.), and Institute of Medical Statistics and Epidemiology (B.H.), Technische Universität München, Ismaninger Strasse 22, 81675 Munich, Germany.
authors.forename: Konstantin
authors.initials: K
authors.lastname: Holzapfel
authors.forename: Jennifer
authors.initials: J
authors.lastname: Regler
authors.forename: Thomas
authors.initials: T
authors.lastname: Baum
authors.forename: Hans
authors.initials: H
authors.lastname: Rechl
authors.forename: Katja
authors.initials: K
authors.lastname: Specht
authors.forename: Bernhard
authors.initials: B
authors.lastname: Haller
authors.forename: Ruediger
authors.initials: R
authors.lastname: von Eisenhart-Rothe
authors.forename: Reiner
authors.initials: R
authors.lastname: Gradinger
authors.forename: Ernst J
authors.initials: EJ
authors.lastname: Rummeny
authors.forename: Klaus
authors.initials: K
authors.lastname: Woertler
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D009423:Nervous System Neoplasms / Q000473:pathology*; D012189:Retrospective Studies; D012509:Sarcoma / Q000473:pathology*; D012983:Soft Tissue Neoplasms / Q000473:pathology*; D019043:Vascular Neoplasms / Q000473:pathology*; D055815:Young Adult