Comparisons between impedance-based and time-based switching bipolar radiofrequency ablation for the treatment of liver cancer

Shelley Yap, Ean H. Ooi, Ji J. Foo, Ean T. Ooi

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3 Citations (Scopus)


Switching bipolar radiofrequency ablation (bRFA) is a cancer treatment technique that activates multiple pairs of electrodes alternately based on a predefined criterion. Various criteria can be used to trigger the switch, such as time (ablation duration) and tissue impedance. In a recent study on time-based switching bRFA, it was determined that a shorter switch interval could produce better treatment outcome than when a longer switch interval was used, which reduces tissue charring and roll-off induced cooling. In this study, it was hypothesized that a more efficacious bRFA treatment can be attained by employing impedance-based switching. This is because ablation per pair can be maximized since there will be no interruption to RF energy delivery until roll-off occurs. This was investigated using a two-compartment 3D computational model. Results showed that impedance-based switching bRFA outperformed time-based switching when the switch interval of the latter is 100 s or higher. When compared to the time-based switching with switch interval of 50 s, the impedance-based model is inferior. It remains to be investigated whether the impedance-based protocol is better than the time-based protocol for a switch interval of 50 s due to the inverse relationship between ablation and treatment efficacies. It was suggested that the choice of impedance-based or time-based switching could ultimately be patient-dependent.

Original languageEnglish
Article number104488
Number of pages12
JournalComputers in Biology and Medicine
Publication statusPublished - Jul 2021


  • Ablation efficacy
  • bRFA
  • Thermal coagulation
  • Thermal therapy
  • Treatment efficacy

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