Radiofrequency Ablation: Temperature Distribution in Adjacent Tissues

Abstract

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.

Zusammenfassung

Zielsetzung: In dieser Kadaverstudie soll die Sicherheit der Anwendung eines Ablationssystems, welches spezifisch für die Ablation von spinalen Metastasen entwickelt wurde, ermittelt werden. Dabei wird der Fokus auf mögliche temperaturbedingte Schädigungen der benachbarten Gewebe gelegt. Material und Methoden: Es wurde ein Tumormodell für 8 Lendenwirbel und 8 Brustwirbel des menschlichen Kadavers erzeugt. Die Ablation der simulierten Tumormasse wurde mit der spezifisch für Wirbelkörpermetastasen entwickelten SpineSTAR-Sonde (SpineSTAR, DFINE Inc., CA) durchgeführt. Während der Ablation wurden die Temperaturen des Wirbelkörpers, des Spinalkanals und des Neuroforamens gemessen. Diese wurden als Mittelwert und Standardabweichung dargestellt und mögliche Unterschiede zwischen der Anwendung der SpineSTAR-Sonde an Lendenwirbeln und Brustwirbeln mittels des Mann-Whitney-U-Tests ermittelt. Ergebnisse: Bei durchgeführter Ablation der Lendenwirbel betrug die maximale Temperatur des unmittelbar an die Ablationszone angrenzenden Bereichs im Wirbelkörper 46,4 ± 3,3 °C, im Bereich des Neuroforamens 37,0 ± 0 °C und im Spinalkanal 37,3 ± 0,7 °C. In den Brustwirbeln erreichte die Temperatur im Wirbelkörper unmittelbar nahe der Ablationszone 44,4 ± 1,7 °C, im Neuroforamen 37,9 ± 1,7 °C und im Spinalkanal 37,25 ± 0,7 °C. Es zeigten sich keine signifikanten Temperaturunterschiede zwischen der durchgeführten Ablation in Lendenwirbeln und Brustwirbeln. Schlussfolgerung: Die Ablation von spinalen Metastasen mittels der SpineSTAR-Sonde erwies sich im Kadavermodell als schonende Methode hinsichtlich möglicher Temperaturschädigungen des angrenzenden Gewebes.

Key words

radiofrequency ablation - spinal metastases - cadaver model - temperature distribution

Schlüsselwörter

Radiofrequenzablation - Wirbelkörpermetastasen - Kadavermodell - Temperaturverteilung

^* Both authors contributed equally to this work.

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