RF ablation at audio frequencies preferentially targets tumor - A finite element study

D. Haemmerich*, D. M. Mahvi, F. T. Lee, J. G. Webster

*Corresponding author for this work

Research output: Contribution to journalConference articlepeer-review

8 Scopus citations


Radio Frequency (RF) ablation has become of considerable interest as a minimally invasive treatment for primary and metastatic liver tumors. Major limitations are small lesion size, which make multiple applications necessary and incomplete killing of tumor cells, resulting in high recurrence rates. RF ablation is typically carried out in the frequency range of around 500 kHz. Measurements have shown a marked difference in electrical conductivity between normal liver tissue and tumor tissue. The difference is most pronounced at frequencies below 100 kHz, where tumors exhibit around two times higher conductivity compared to normal tissue. Conductivity is similar for tumor and normal liver at 500 kHz. We created Finite Element Method (FEM) models of the RITA model-30 multi-prong probe. The probe was placed in a tumor of 20 mm diameter. We simulated 12 minute, temperature-controlled RF ablation at 95°C at frequencies of 20 kHz and 500 kHz. At 20 kHz we observed increased current density within the tumor boundaries. This resulted in an increase in lesion size by 29% at a frequency of 20 kHz compared to 500 kHz.

Original languageEnglish (US)
Pages (from-to)1797-1798
Number of pages2
JournalAnnual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings
StatePublished - 2002
EventProceedings of the 2002 IEEE Engineering in Medicine and Biology 24th Annual Conference and the 2002 Fall Meeting of the Biomedical Engineering Society (BMES / EMBS) - Houston, TX, United States
Duration: Oct 23 2002Oct 26 2002


  • Liver ablation
  • Liver cancer
  • Liver tumor
  • RF ablation
  • RFA
  • Radiofrequency ablation

ASJC Scopus subject areas

  • Signal Processing
  • Health Informatics
  • Computer Vision and Pattern Recognition
  • Biomedical Engineering


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