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Numerical investigation of the effectiveness of cryosurgery on a liver tumor

Authors :

Taha Samiazar¹ Mahkame Sharbatdar²

1- Faculty of Mechanical Engineering, Khajeh Nasiruddin Toosi University of Technology, Tehran, Iran 2- Faculty of Mechanical Engineering, Khajeh Nasiruddin Toosi University of Technology, Tehran, Iran

Keywords :

Cryosurgery،Numerical Simulation،Volume Fraction،Necrotic Tissue،Ice Ball Irregularity

Abstract :

Cryosurgery is known as a minimally invasive treatment for those who suffer from different types of cancers, such as liver cancer. The treatment includes applying an extremely cold procedure by liquid nitrogen or argon gas to eradicate tumors. Indeed, cryosurgery freezes the tissue, leading to the death of the tumor cells. However, it is possible that some parts of the healthy tissue get damaged undesirably during cryosurgery. In this numerical study, the ideal vessel, cryoprobe, and liver tissue, with proper physical characteristics, are considered with the aim of quantifying and assessing the effectiveness of the surgery. Moreover, the effect of the convection heat transfer of the vessel caused by ice ball formation is investigated. Physical characteristics of the tumor were added to the model, which contributed to being as accurate as possible. To evaluate the damage rate of the tumor, four parameters are defined: cryoablation coverage ratio (CACR), volume fraction (VF), tissue damage (TD), and ice ball irregularity (IBI). The effectiveness of surgery is reported by the four mentioned parameters. Ultimately, the temperature distribution, the shape of the eventually formed ice ball, and the amount of thermal damage have been analyzed. Hence, the provided graphs as key results in this investigation illustrate that considering tumor properties leads to lessening evaluation parameters of CACR, VF, and TD by 18%, 5%, and 33%, and raising IBI by 100%, respectively. Also, the VF remains constant in these two states. These methods may be utilized to evaluate the cryosurgery procedure.