title: Radiofrequency ablation of osteoid osteoma: initial results with a bipolar ablation device.
abstract: OBJECTIVE
  To report the initial results with percutaneous radiofrequency (RF) ablation of osteoid osteomas with a bipolar ablation device.
  
  
  METHODS
  Twelve patients (seven male patients and five female patients; mean age, 17.3 years; age range, 6-36 y) with clinically and radiologically suspected osteoid osteoma were treated with computed tomography-guided percutaneous bipolar RF ablation. The procedure was performed with the patients under general anesthesia. After localization of the nidus, an 11-gauge hollow drill was introduced into the nidus through a 9-F introducer sheath. A bipolar 18-gauge RF probe with a 9-mm active tip was inserted through the introducer sheath and connected to the RF generator. Energy application was started at 2 W and subsequently increased to a maximum of 5 W. The procedure was terminated if a resistance of 900 Omega was reached.
  
  
  RESULTS
  Mean duration of energy deposition was 8.3 +/- 4.0 minutes, with a mean energy application of 1.8 +/- 2.9 kJ (range, 0.3 - 7 kJ). In one patient, the intervention had to be repeated twice to achieve total pain relief. Eleven of 12 patients (92%) remained free of symptoms at a follow-up time of 15.1 +/- 9.5 months (range, 5 - 31 months). One patient had recurrence of pain 16 months after the procedure and was treated surgically. No complications occurred. Patients resumed normal activity within 24 hours.
  
  
  CONCLUSIONS
  Percutaneous bipolar RF ablation is an efficient and safe treatment of osteoid osteoma. Short-term efficacy of bipolar RF ablation may rival the results of monopolar RF ablation. Further studies are needed to address the long-term efficacy of this technique.
authors.affiliation: Department of Diagnostic Radiology, RWTH Aachen University, Aachen, Germany. mahnken@rad.rwth-aachen.de
authors.forename: Andreas H
authors.initials: AH
authors.lastname: Mahnken
authors.forename: Josef A
authors.initials: JA
authors.lastname: Tacke
authors.forename: Joachim E
authors.initials: JE
authors.lastname: Wildberger
authors.forename: Rolf W
authors.initials: RW
authors.lastname: Günther
mesh_terms: D000293:Adolescent; D000328:Adult; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000601:surgery*; D017115:Catheter Ablation / Q000295:instrumentation*; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D010017:Osteoma, Osteoid / Q000000981:diagnostic imaging / Q000601:surgery*; D012008:Recurrence; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome