title: Treatment of Osteoid Osteomas Using a Navigational Bipolar Radiofrequency Ablation System.
abstract: BACKGROUND
  Percutaneous CT-guided radiofrequency ablation is a safe and effective minimally invasive treatment for osteoid osteomas. This technical case series describes the use of a recently introduced ablation system with a probe that can be curved in multiple directions, embedded thermocouples for real-time monitoring of the ablation volume, and a bipolar design that obviates the need for a grounding pad.
  
  
  METHODS
  Medical records of all patients who underwent radiofrequency ablation of an osteoid osteoma with the STAR Tumor Ablation System (DFINE; San Jose, CA) were reviewed. The location of each osteoid osteoma, nidus volume, and procedural details were recorded. Treatment efficacy and long-term complications were assessed at clinical follow-up.
  
  
  RESULTS
  During the study period, 18 osteoid osteomas were radiofrequency ablated with the multidirectional bipolar system. Lesion locations included the femur (50%; 9/18), tibia (22%; 4/18), cervical spine (11%; 2/18), calcaneus (5.5%; 1/18), iliac bone (5.5%; 1/18), and fibula (5.5%; 1/18). The median nidus volume of these cases was 0.33 mL (range 0.12-2.0 mL). All tumors were accessed via a single osseous channel. Median cumulative ablation time was 5 min and 0 s (range 1 min and 32 s-8 min and 50 s). All patients with clinical follow-up reported complete symptom resolution. No complications occurred.
  
  
  CONCLUSIONS
  Safe and effective CT-guided radiofrequency ablation of osteoid osteomas can be performed in a variety of locations using a multidirectional bipolar system.
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway Boulevard, Saint Louis, MO, 63110, USA. wallacea@mir.wustl.edu.
authors.forename: Adam N
authors.initials: AN
authors.lastname: Wallace
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway Boulevard, Saint Louis, MO, 63110, USA.
authors.forename: Anderanik
authors.initials: A
authors.lastname: Tomasian
authors.affiliation: Washington University School of Medicine, 660 South Euclid Avenue, Saint Louis, MO, 63110, USA.
authors.forename: Randy O
authors.initials: RO
authors.lastname: Chang
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway Boulevard, Saint Louis, MO, 63110, USA.
authors.forename: Jack W
authors.initials: JW
authors.lastname: Jennings
mesh_terms: D000293:Adolescent; D000328:Adult; D001859:Bone Neoplasms / Q000601:surgery*; D017115:Catheter Ablation / Q000295:instrumentation*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010017:Osteoma, Osteoid / Q000601:surgery*; D015641:Radiography, Interventional; D012189:Retrospective Studies; D013238:Stereotaxic Techniques; D025321:Surgery, Computer-Assisted; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: CT; Osteoid osteoma; Radiofrequency ablation