Indirect heating strategy for laser induced hyperthermia: An advanced thermal model

A novel heating strategy based on laser irradiation of surrounding tissues as an alternative to direct irradiation of superficial tumors is proposed and analyzed for the first time. The computational analysis is based on two-dimensional axisymmetric models for both radiative transfer and transient heat transfer in the human body. A diffuse component of the radiation field is calculated using P1 approximation. Coupled transient energy equations and kinetic equations for composite human tissue take into account the metabolic heat generation and heat conduction, blood perfusion through capillaries, the volumetric heat transfer between arterial blood and tissue, the thermal conversions in blood and tumor tissue, the periodic laser heating, and also heat exchange between a human body and ambient medium. An example problem for a superficial human cancer has been solved numerically to illustrate the relative role of the problem parameters on the transient temperature field during hyperthermia treatment. In particular, the effect of embedded gold nanoshells which strongly absorb the laser radiation is analyzed. It is shown that required parameters of tumor hyperthermia can be also reached without gold nanoshells.