Radiofrequency ablation of osteoid osteoma.

The main purpose of this thesis was to evaluate the effectiveness and safety of CT-guided radiofrequency ablation for the treatment of spinal and non-spinal osteoid osteomas. Furthermore, the technical requirements needed for safe radiofrequency ablation and the clinical outcome after radiofrequency ablation of spinal and non-spinal osteoid osteomas are discussed. The possible causes of treatment failure and methods for the detection of treatment failure were also analysed with the purpose of optimizing patient selection and the radiofrequency procedures, and solving high risk parameters for failure of treatment.\nChapter two discusses the clinical outcome of a large series of 97 patients with spinal and non-spinal osteoid osteomas treated by radiofrequency ablation. Chapter three describes the theoretical and technical background of radiofrequency ablation. The concept of the treatment zone as well as related safety issues are also discussed. In Chapter four the possible mechanisms causing treatment failure are discussed. The potential role of CT and MRI imaging in the detection of recurrent or residual osteoid osteoma is addressed in Chapter five. Finally the treatment outcome of a group of 25 patients with spinal osteoid osteoma treated by radiofrequency ablation is presented in Chapter 6. A general discussion is provided in Chapter 7.