Percutaneous radiofrequency ablation of spinal osteoid osteoma under CT guidance

Objective:

Osteoid osteoma (OO) accounts for approximately 10–12% of all benign bone tumours and 3% of all bone tumours. Spinal involvement appears in 10–25% of all cases. The purpose of this study was to evaluate the safety and efficacy of CT-guided radiofrequency (RF) ablation in the treatment of spinal OOs and report our experience.

Methods:

13 patients suffering from spinal OO and treated at the authors'' institution using CT-guided RF ablation were retrospectively evaluated. The RF probe was introduced through a 11-G Jamshidi® needle, and the lesion was heated at 90 ^°C for 6 min.

Results:

All procedures were considered technically successful as the correct positioning of the probe was proven by CT. 11 of the 13 patients reported pain relief after RF ablation. In two cases, RF ablation was repeated 1 month after the first procedure. Pain relief was achieved in both cases after the second procedure. No recurrence was reported throughout the follow-up. No complications like skin burn, soft-tissue haematoma, infection, vessel damage or neurological deficit were reported.

Conclusion:

This study demonstrates that CT-guided percutaneous RF ablation is a safe and effective method for the treatment of spinal OOs.

Advances in knowledge:

The data of this study support the efficacy and safety of the recently applied CT-guided percutaneous RF ablation technique for the treatment of spinal OOs.Osteoid osteoma (OO) represents a benign bone tumour first described by Jaffe¹ in 1935. The lesion accounts for approximately 10–12% of all benign bone tumours and 3% of all bone tumours. It is characterized by a nidus, consisting of osteoid, osteoblasts and fibrovascular stroma, surrounded by sclerotic bone usually measuring <1.5 cm in diameter. OOs are characteristically seen in children and young adults with a predilection for long bones, particularly in lower extremities.² Spinal involvement usually affecting the posterior elements appears in 10–25% of all cases.^3,4 The typical symptom is localized pain typically worsening at night, ameliorated by the administration of salicylates (acetylsalicylic acid) or non-steroidal anti-inflammatory drugs (NSAIDs). In spinal cases of OO, radiation of pain distally to the lesion site might simulate radiculopathy similar to disc herniation especially if the lesion is located close to a nerve root. Painful antalgic scoliosis is frequent in thoracolumbar lesions in children and adolescents.^5,6 Spinal lesions are usually difficult to diagnose, and the reported delay from presentation to final diagnosis and treatment can be as long as 24 months in some cases.^7–9 Neurologic deficit does not generally appear.In the past, conventional surgical excision and more recently minimally invasive surgery techniques were the treatment of choice in cases of spinal OOs when conservative treatment with anti-inflammatory and salicylates fails or is contraindicated.^10–15Rosenthal et al¹⁶ first introduced percutaneous radiofrequency (RF) ablation for the treatment of OOs. The effectiveness of RF ablation of OOs localized in the extremities and pelvis has been proven by many studies.^16–19Percutaneous RF ablation for the treatment of spinal OOs is not widely used, probably owing to the potential danger to the adjacent neural and vascular elements. In recent years, however, some clinical studies reported good results in the management of spinal OOs using CT-guided RF ablation.^8,20–23The purpose of this study was to evaluate the safety and efficacy of CT-guided RF ablation in the treatment of spinal OOs and report our experience.