gms | German Medical Science

Objective: Radiofrequency ablation (RFA) is an interventional method to treat metastases of the spine. RFA leads to a heat build-up to 75 ° C in the tumor, which rapidly drops to normal body temperature in the periphery. But nevertheless heating of the nerves and the spinal cord could lead to their damage. In this study temperature distribution is shown directly at the dura and demonstrated with some examples.

Methods: RFA was performed in 12 patients with metastases involving the spinal canal. The ablation probe is equipped with a distal and a proximal Temperature-probe. The temperature directly at the nerve and the spinal cord was measured with a third T-Probe. In an overheating of more than 38.5 ° C, the nerve was cooled by flushing with saline.

Results: The maximum reached temperature in the tumor center was 71.33 °C (+/- 1.53). In the periphery of the ablation probe, the heat generation was always 50 °C. At the nerve and the spinal cord temperatures were measured on average 37.17 °C (+/- 2.03). Peaks of 38.5 °C up to 40 °C have been successfully reduced to normal of 36 °C by flushing. In all cases an effective ablation temperature in the center of the tumors are achieved. At the nerve and the spinal cord temperatures rose up to 40 °C. It could be cooled by flushing with saline. Without cooling the heat can rise to critical values and cause damage to the nerve or the spinal cord.

Conclusion: The heat distribution distally and proximally of the ablation can be tracked well and is effective. The heat in the vicinity of neural structures is moderate. T-peaks can be intercepted by flushing and thus further increase with potential damage to the nerve and the spinal cord can be prevented.