Heat and mass transport in tumor tissues subject to alkali metal thermo-chemical ablation

Alkali metal thermochemical ablation is a promising anti-tumor therapy in which tumor tissue can be efficiently destroyed via both heat and hydroxyl ions released from the chemical reaction in tissue between an alkali metal and water. Encouraging results have been reported from in vitro and in vivo trials in a previous study. However, the precise process of heat and mass transfer triggered by the above thermochemical reaction in tumor tissue has still remained confusing. Here, to better understand the temperature and pH responses of tumor tissue subject to alkali metal therapy, a theoretical model coupling temperature and concentration field is developed for characterizing the physicochemical reaction and the transport process occurring around the inserted sodium capsule during treatment. Preliminary experiments in tumor tissue are performed to validate the theoretical predictions of temperature, and the results indicate that the bioheat transfer model can predict the temperature responses in the tissues heated by the sodium capsule very well. Furthermore, comprehensive parametric studies are performed to evaluate the effects of either physiological or physicochemical parameters, including ablation time, time lags, and blood perfusion rate. Based on the numerical results, useful instructions are suggested for planning alkali metal tumor ablation treatment.