Numerical study on the cryosurgery of gel mimicking tissue phantoms

Abstract

Curing of cancerous tumour using cryosurgery is accepted in the present time. But still its adoption is challenged because of its lower efficacy and a threat to the healthy cells. It is difficult to stop the lethal front from entering into healthy tissue zone. Therefore, complete destruction of defected tissue along with protection of neighboring healthy tissue is of main concern. To vanquish these constraints, many approaches have been used so far. In this numerical analysis, an approach is proposed in which a localised specific solution with lower thermal conductivity is injected to cover the axial portion of tumour. For this purpose, perfluorohexane is used which has a low thermal conductivity. With this novel approach, freezing becomes very fast and significant along with the minimal damage to the surrounding health tissue. It also helps in achieving lethal temperature in shorter time span. The propagation of the lethal front is calculated numerically. These real time lethal volume data helps the clinical practitioners in estimation of extent of freezing necrosis and time duration for cryosurgery. A parametric study was performed on tissue mimicking gel with various insertion depths of cryoprobe and different concentrations of gel. Both the parameters have a remarkable effect on the amount of freezing. The problem is analyzed using multi block structured grid and numerical results obtained showed good compliance to the experimental data.