Radiofrequency Ablation: Temperature Distribution in Adjacent Tissues

PURPOSE: This clinical study investigates the use of a radiofrequency ablation system specifically developed for the ablation of spinal metastases. The investigation examines possible temperature-associated risks for the adjacent tissues. MATERIAL AND METHODS: A tumour model was simulated for 8 lumbar and 8 thoracic vertebrae of a human cadaveric spine. The tumour mass was ablated with the SpineSTAR electrode (SpineSTAR, DFINE Inc., CA), which has been specifically developed for the ablation of spinal metastases. During the ablation procedure, the temperatures of the vertebra, the epidural space, and the neural foramen were measured with thermocouples. These temperatures were documented as means with standard deviations. Possible differences between lumbar and thoracic vertebrae were analysed with the Mann-Whitney U test. RESULTS: The maximal temperature of the lumbar vertebrae was 46.4 ± 3.3 °C near to the ablation zone, the temperature of the neural foramen was 37.0 ± 0 °C, and the temperature of the epidural space was 37.3 ± 0.7 °C. In the thoracic vertebrae, the temperature was 44.4 ± 1.7 °C near to the ablation zone, 7.9 ± 1.7 °C in the neural foramen, and 37.25 ± 0.7 °C in the epidural space. There was no significant difference in temperature distribution between treated lumbar and thoracic vertebrae. CONCLUSION: Ablation of spinal metastases in a cadaveric model using the SpineSTAR electrode was shown to be a safe method with respect to possible temperature-related risks for the adjacent tissues.