Percutaneous radiofrequency ablation for spinal osteoid osteoma and osteoblastoma

We sought to verify the efficacy and safety of RFA in spinal OO and osteoblastomas (OB) (Enneking Stage 2, S2). We retrospectively reviewed patients treated in our hospital. Surgical resection was indicated for Enneking Stage 3 OB. RFA indications for spinal OO and OB (S2) were no neurological deficits, complete bone cortex around the lesion on computed tomography (CT), and cerebrospinal fluid between a lesion and the spinal cord/nerve root on magnetic resonance imaging. Abundant cerebrospinal fluid (more than 1.0 mm) between the lesion and nerve root/spinal cord was preferred to prevent neurological damage by heat. Otherwise, surgery was recommended. The minimum follow-up was 24 months. Ten patients were treated with CT-guided percutaneous RFA, including three with OB and seven with OO. No patients had neurological deficits or scoliosis. In OO patients, the average visual analog scale (VAS) scores were 7.6/10 (range 6-10) before RFA. In OB cases, the VAS scores were 8, 7, and 9 before RFA. Nine patients had a one-stage biopsy and then RFA, and one patient had a two-stage procedure (biopsy before RFA). The average RFA time for OO was 10 min (range 4-12). In the three OB cases, the RFA time was 12, 12, and 24 min. The time of the whole produce was 98 min (range 65-130 min). All 10 patients were followed-up. The average follow-up time of OO was 46.6 months (range 24-66). Six patients were free of pain, except one who suffered occasional pain with VAS 2/10. The three OB cases were free of pain at 24, 26, and 26 months. CT-guided percutaneous RFA is a safe and effective treatment for spinal OO and S2 OB, especially in lesions with no neurological deficits and intact cortical bone. Cerebrospinal fluid around the lesion is an appropriate indication for percutaneous RFA.