Radiofrequency ablation in breast tissue: experimental study for evaluation of radiofrequency effects in the bovine udder and review of the literature.

Purpose: To investigate the radiofrequency (RF) effects on the nonlactating and lactating ex vivo bovine udder as a model for normal breast tissue.

Materials And Methods: RF ablation in three lactating and three nonlactating ex vivo bovine udders (ie, six udders) was performed. The opening of the electrodes was 3 cm. The temperature was applied in 10 degrees C increasing steps between 60 degrees C and 100 degrees C and each temperature was maintained for 15 minutes. The experiment was repeated three times for each temperature step in the lactating and nonlactating udder. Resected specimens were assessed histologically. The maximum diameter of the ablation zone and maximum width of the transition zone with respect to the temperature applied were measured.

Results: In the nonlactating tissue, there was a correlation of the temperature and diameter of tissue damage. There was a narrow transition zone of 0.10 cm in all cases except at 100 degrees C, when it was 0.17 cm. In the lactating udder, no correlation was seen. The transition zone was not well visualized at temperatures less than 80 degrees C, ranging in overall size between 0.15 cm and 0.20 cm.

Conclusions: The results of the study, with clear demarcation of the ablation zones and transition zones in the normal breast tissue, support the potential of breast thermal ablation as a viable treatment for further study. Lactating tissue does not seem ideal for thermal ablation. The discrepancy of the extent of ablation and the length of the electrodes is an important finding in this study. Further in vivo studies in normal glandular tissue and tumor are necessary.