A dual reciprocity boundary element method for photothermal interactions in laser-induced thermotherapy

Laser-induced thermotherapy (LITT) is a minimally invasive laser hyperthermia procedure for the treatment of localized tumors. Mathematical modeling of the photothermal processes in laser-irradiated tissues is essential for optimal treatment planning. In this study, A Monte Carlo method is introduced to simulate photon transport in the tumor tissues with complex geometries. The dual reciprocity boundary element method (DRBEM) is then formulated to solve the bioheat transfer equation in the tumors. The model is validated with the finite difference solutions. To illustrate the applications of the proposed DRBEM, several laser delivery schemes, including external laser irradiation, single or multiple laser fiber delivery applicators, are studied for tumors with regular or irregular geometric shapes. The temperature transients, laser energy distribution and coagulation patterns for different laser delivery modes are demonstrated. The unique advantages of the DRBEM, such as easy adaptability to complex tumor geometries and no need to discretize the inner domain, may make it well-suited and robust approach for predicting and controlling the temperature evolution in laser-induced thermotherapy procedure.