545 Radiofrequency Ablation (RFA) - Treatment of Choice for Osteoid Osteoma
Background and aims: Osteoid osteoma is a relatively common benign bone tumor. Until recently, treatment has been surgical excision of the nidus. In 1992 Radiofrequency ablation (RFA) was first reported as a new method of treatment. Our aim is to evaluate the efficacy and safety of Computed Tomography (CT) guided RFA as a minimally invasive therapy for osteoid osteoma. Methods: 17 patients aged 11-18 years were treated with RFA sessions. Osteoid osteomas were located in femoral body (5), tibial body (3), inferior articular surface of tibia (3), superior articular surface of tibia (2), sacrum (2), cotyle (1) and vertebral arc (1). RFA was performed under sedation. After localization of the nidus, with 3mm CT slices osseous access was achieved with a 2 mm coaxial drill system, through which an expandable RF electrode with 7 arrays was advanced. RF energy was applied for 6-10 min at 80-110C. A technically successful ablation was regarded when electrode was placed within the center of the nidus and the desired temperature was achieved. Clinical success was evaluated with the Brief Pain Inventory (BPI) which was calculated before and after (1, 4 and 12 months) the treatment. Results: Technical success was 100%. Clinical success was achieved in 94, 1% of the lesions (16/17). One patient had recurrence of pain at 5 months and a second RFA was performed successfully. No immediate or delayed complication was observed. Conclusions: CT-guided percutaneous RFA is a safe, efficient, cost effective and minimally invasive method for treatment of osteoid osteomas.