Theoretical evaluation of bio-thermal response in human tissue subjected to pulse-laser induced hyperthermia therapy for cancer treatment

Abstract

This paper aims to develop a theoretical estimation of thermal response in human tissues appearing in a hyperthermia treatment under the influence of laser-induced external heat sources. In general, to develop a theoretical investigation on bioheat transfer, the fundamental aspect is to adopt an appropriate thermal model for predicting the correct thermal response. Among the existing bioheat models, the two-temperature model is considered to be the most feasible one, as it takes into account the arterio-vascular architectural interaction in the analysis. This model is established based on the local thermal non-equilibrium (LTNE) approach. The exact solution of the two-temperature bioheat model has been established by the implementation of the combined scheme of Duhamel's theorem and the Finite integral transform method. A pulse laser heating applied externally as a therapeutic heat source is introduced newly in the area of the LTNE bioheat modelling whereas the existing research works were developed by utilizing scattering laser heat sources. The thermal response of the tissue is analyzed for different laser variables such as laser intensity, optical penetration depth, pulse laser time, and laser irradiation radius. A parametric study has been made to set a theoretical treatment protocol for hyperthermia therapy and correspondingly, the thermal field has been developed within the prescribed peak temperature spectrum for the hyperthermia treatment. The thermal field has also been investigated for various biological parameters, viz. blood perfusion rate, porosity, and pore diameter of the blood vessel. The present research outcome depicts that the hyperthermia temperature can be achieved at the optical penetration depth of 0.0005 m with the laser irradiation radius in the range of 0.004 m–0.008 m. From the present work, it can be highlighted that the health monitoring of infected tissues or the organ of the human body is necessary before processing therapeutic heating as the thermal field depends on the porosity of tissue significantly. A qualitative investigation between pulse heating and scattering laser heating depicts that pulse laser heating is a better option to choose for the thermal therapy for the curtailment of the possibility of thermally induced damage of healthy tissues. A successful verification and authentication study has been carried out between the present work and the published experimental and theoretical works.