Radiofrequency ablation of osteoid osteoma with cooled probes and impedance-control energy delivery

Our objective was to evaluate the efficacy of percutaneous radiofrequency ablation of osteoid osteoma with cooled radiofrequency probes and impedance control energy delivery from a 200-W generator. We also compared the outcome to published data for therapy with a 5-mm noncooled probe and temperature-controlled short-duration therapy protocols.

Radiofrequency ablation was performed on 11 patients with a clinical and radiologic diagnosis of osteoid osteoma. A cooled radiofrequency probe was introduced into the lesion under CT guidance. Twelve minutes of radiofrequency energy was delivered from a 200-W generator under impedance control. Postprocedural pain, function, and satisfaction were evaluated by means of an interview and questionnaire.

All procedures were technically successful. No serious complication occurred. Postoperative pain was scored at a mean of 6.9 +/- 3.06 (95% confidence interval) on a numeric rating scale. Postoperative pain was rated as similar to night pain. By 1 week after therapy, all patients had resolution of pain and returned to normal activity. There was no recurrence during the follow-up period (range, 6-27 months; mean, 14.4 months). Patients rated their satisfaction as high.

Radiofrequency ablation of osteoid osteoma with a high-energy delivery technique is safe and has a high success rate. When compared with patients in a published series using 5-mm probes and manual energy control from lower-output generators, our cohort showed increased postoperative pain scores and an increased interval to symptom resolution.