Radiofrequency ablation of osteoid osteoma using tissue impedance as a parameter of osteonecrosis

Abstract

Introduction: The aim of this study is to assess the safety and the efficacy of radiofrequency ablation (RFA) of osteoid osteoma with Soloist monopolar electrode using tissue impedance, rather than temperature, as an indicator of osteonecrosis. Methods: The medical records and imaging studies of 30 patients (males 18, females 12) who underwent RFA of osteoid osteoma at our institution were reviewed. The mean age of the patients was 15.3 years (range 5-34 years) and the mean duration of follow up was 26.9 months (range 3-52 months). The lesions were located in the femur (n = 6, 53%), tibia (n = 8, 27%), hand (n = 3, 10%), foot (n = 2, 6%) and humerus (n = 1, 3%). The procedure was performed with general anaesthesia under CT guidance. The nidus was accessed with 11-gauge bone biopsy needle and then the stylet was removed and replaced by monopolar 16.5G radiofrequency probe with a 9-mm active tip through the coaxial axis. Power delivery via the radiofrequency generator was started at 2 W and increased gradually until the end point of 450-500 W reached and 'Roll-Off' achieved indicating coagulation necrosis of the target lesion. Results: The procedure was technically successful in all patients. The mean procedure time was 72 min and the mean RFA time was 12.7 min. The clinical success rate was 93%. In one patient, the procedure was abandoned due to immature Roll-Off despite all measures. In one patient (3%), recurrence occurred 39 months after the procedure. No major complications were encountered. Two minor skin burns occurred that were resolved with conservative measures. Conclusion: RFA of osteoid osteoma using Soloist monopolar electrode is a safe and effective treatment. Tissue impedance could be used as an alternative to temperature to indicate osteonecrosis of osteoid osteoma during RFA.

Radiofrequency ablation of osteoid osteoma: Aiming for excellent outcomes in an Australasian context

“…This is in accordance with experimental work indicating that such a protocol should produce effective treatment . With the LeVeen system, a low initial power setting was chosen (typically 5 watts) and subsequently increased until impedance ‘roll‐off’ occurred in a similar manner to that reported by others . Using this system, each patient received a series of relatively short cycles of heating lasting from 15 seconds to 10 minutes, with total heating time from 1 to 21 minutes.…”

Intra-articular osteoid osteoma as a differential diagnosis of diffuse mono-articular joint pain

“…In our case, it has to be expected that the necrosis zone will only revitalize very slowly, if at all. The use of alternative methods including tissue impedance as a parameter of osteonecrosis [25] or magnetic resonance-guided focused ultrasound [26] might be promising and gentle alternatives. Nonetheless, further investigation including large multi-center studies is needed to compare outcomes between these new methods and RFA.…”

Computer modelling of RF ablation in cortical osteoid osteoma: Assessment of the insulating effect of the reactive zone

“…Although OO is benign and spontaneous remission occasionally occurs, an intervention for definitive relief of pain is sometimes required [2]. Among others techniques [3], radiofrequency ablation (RFA) is a minimally invasive technique which allows thermal destruction of the OO [4][5][6].…”

“…Most OOs are cortical and macroscopically consist of a nidus of active bone surrounded by a reactive zone. The nidus, usually 5-10 mm in diameter [2], is the actual tumor, and hence the target of the RFA. The reactive zone of a cortical OO is partially surrounded by the cortex (cortical bone) while the rest is enclosed by trabecular bone (Figure 1).…”