How Does Thyroid RFA work?
Thyroid RFA works similar to liver RFA and refers to heat ablation by high frequency alternating electric current oscillating between 200 and 1200 kHz.
H. Rhim, S. N. Goldberg, G. D. Dodd III et al., “Essential techniques for successful radio-frequency thermal ablation of malignant hepatic tumors,” Radiographics, vol. 21, pp. S17–S35, 2001
The thyroid RFA electrode placed into the nodule, produces high-frequency alternating current passing into the surrounding tissue. The rapid vibration of surrounding ions and frictional heat causes necrosis and irreversible damage near the electrode at temperature between 50°C and 100°C. Temperature higher than 100°C would lead to vaporization and carbonization.
L. Buscarini and S. Rossi, “Technology for radiofrequency thermal ablation of liver tumors,” Surgical Innovation, vol. 4, no. 2, pp. 96–101, 1997.
Beside the frictional heat produced by oscillating ions, conduction of heat causes further damages to the surrounding remote area in a slower manner.
This is the basis of RFA.
S. N. Goldberg, “Radiofrequency tumor ablation: principles and techniques,” European Journal of Ultrasound, vol. 13, no. 2, pp. 129–147, 2001.
In this experimental study, temperature measurements around the RFA electrode in the pig thyroid gland were taken. The maximum temperature at a distance of 5 mm from the RFA electrode was between 44°C and 61°C while, at a distance of 10 mm, a maximum temperature of 53°C was achieved. Even at this low temperature, there were signs of irreversible cell death damage in the region of the thermal lesions.
J.-P. Ritz, K. S. Lehmann, T. Schumann et al., “Effectiveness of various thermal ablation techniques for the treatment of nodular thyroid disease—comparison of laser-induced thermotherapy and bipolar radiofrequency ablation,” Lasers in Medical Science, vol. 26, no. 4, pp. 545–552, 2011
Richard Guttler MD,FACE,ECNU
Clinical Professor of Medicine Keck/USC school of Medicine
Director, Santa Monica Thyroid Center, Santa Monica Ca 90404
Member, American Association of Clinical Endocrinologist’s task force on the introduction of thyroid radiofrequency ablation RFA of thyroid nodules to the United States.