Adjuvant-perfluorocarbon based approach for improving the effectiveness of cryosurgery in gel phantoms

Abstract

The current study suggests novel methods to enhance freezing inside the tissue mimicking gel phantoms during the cryosurgery process. In this study, freezing of gel phantoms is carried out by a cryosurgery setup and the temperature is measured in real time using a data acquisition system. Alumina is used as an adjuvant and the variation of the alumina concentration in the gel phantoms results in a decrease of end temperature achieved after cryosurgery. However, the lowest end temperature is attained when the alumina concentration in the gel phantom is 1% (w/v) and for further studies this optimal concentration is utilised. It is observed that with the increase in insertion depth of the cryoprobe (from 1 to 1.5 cm), there is a decrease in end temperature at each thermocouple location in these alumina gel phantoms. The cooling of these alumina containing gel phantoms in presence of a perfluorohexane layer reveals that there is an inhibition of freezing due to this low thermal conductivity barrier (the axial ice ball depth is reduced from 2 cm to 1.5 cm). Furthermore, with the addition of glycine (i.e. 1% (w/v) alumina 5% (w/v) glycine gel phantom), a substantial end temperature decrease is observed at the thermocouples placed nearer to the cryoprobe, thus indicating the usefulness of this strategy in enhancing localised freezing. In conclusion, this study provides various new approaches that enhance the efficacy of cryosurgery immensely.