title: CT-guided stereotactic targeting accuracy of osteoid osteoma.
abstract: BACKGROUND
  The aim of this study was to evaluate the CT-guided stereotactic targeting accuracy for radiofrequency ablation of osteoid osteoma (OO), a small, benign but painful osseous lesion.
  
  
  METHODS
  Patient and extremity were fixed in a vacuum cushion. The OO was targeted using an optical navigation system with a stereotactic targeting device. For evaluation of targeting errors, the control CT with the needle in place was fused with the planning CT.
  
  
  RESULTS
  In 16 consecutive patients, nine OOs in the femur, four in the tibia, one in the spine, one in the ulna and one in the pubic bone were successfully targeted without complications. The mean ± SD lateral targeting error was 2.6 ± 1.7 mm at the needle entry and 1.9 ± 1.2 mm at the needle tip, and the mean angular error was 2.0 ± 1.3°.
  
  
  CONCLUSIONS
  Stereotaxy allows for accurate and safe targeting of OOs in various bone regions.
authors.affiliation: Section of Microinvasive Therapy, Department of Radiology, Innsbruck Medical University, Austria.
authors.forename: Gerlig
authors.initials: G
authors.lastname: Widmann
authors.forename: Peter
authors.initials: P
authors.lastname: Schullian
authors.forename: Martin
authors.initials: M
authors.lastname: Fasser
authors.forename: Christian
authors.initials: C
authors.lastname: Niederwanger
authors.forename: Reto
authors.initials: R
authors.lastname: Bale
mesh_terms: D000293:Adolescent; D000328:Adult; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D002648:Child; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D010017:Osteoma, Osteoid / Q000000981:diagnostic imaging / Q000601:surgery*; D015641:Radiography, Interventional; D016634:Radiosurgery / Q000379:methods*; D025321:Surgery, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed; D055815:Young Adult