Treatment of Osteoid Osteomas Using a Navigational Bipolar Radiofrequency Ablation System

Percutaneous CT-guided radiofrequency ablation is a safe and effective minimally invasive treatment for osteoid osteomas. This technical case series describes the use of a recently introduced ablation system with a probe that can be curved in multiple directions, embedded thermocouples for real-time monitoring of the ablation volume, and a bipolar design that obviates the need for a grounding pad.

Medical records of all patients who underwent radiofrequency ablation of an osteoid osteoma with the STAR Tumor Ablation System (DFINE; San Jose, CA) were reviewed. The location of each osteoid osteoma, nidus volume, and procedural details were recorded. Treatment efficacy and long-term complications were assessed at clinical follow-up.

During the study period, 18 osteoid osteomas were radiofrequency ablated with the multidirectional bipolar system. Lesion locations included the femur (50%; 9/18), tibia (22%; 4/18), cervical spine (11%; 2/18), calcaneus (5.5%; 1/18), iliac bone (5.5%; 1/18), and fibula (5.5%; 1/18). The median nidus volume of these cases was 0.33 mL (range 0.12-2.0 mL). All tumors were accessed via a single osseous channel. Median cumulative ablation time was 5 min and 0 s (range 1 min and 32 s-8 min and 50 s). All patients with clinical follow-up reported complete symptom resolution. No complications occurred.

Safe and effective CT-guided radiofrequency ablation of osteoid osteomas can be performed in a variety of locations using a multidirectional bipolar system.