Prostate cancer focal laser ablation: multi-objective optimization of the treatment

Laser-induced hyperthermia is an innovative technique for different prostate diseases, being a minimally invasive therapy. Due to its characteristics, the ablative procedure is also spreading in prostate cancer treatment. Due to the low invasiveness, in many cases it can be preferred to conventional high-invasive protocols (surgery, chemotherapy or radiotherapy). This procedure aims to deliver a certain amount of thermal energy, increasing the temperature in the target and inducing a cellular death (necrosis) in the target tissue. Being quite a new procedure, recognized guidelines are still missing, increasing uncertainty in the procedure's outcomes. Therefore, it is crucial to further investigate focal laser ablation to properly set the protocol parameters, maximizing tumor necrosis, avoiding excessive damage of the surrounding healthy tissue. For all these reasons, in the present study a Pareto optimization, carried out with a multi-objective genetic algorithm, is employed to find the best combination of design variables to optimize the treatment. The genetic algorithm is implemented in MATLAB environment, and it is coupled with the finite element commercial code COMSOL, which is employed to carry out numerical simulations. The heat transfer in the biological media is solved with well-known Pennes’ approach. Results show that, by employing the utopian criterion, the optimization allows to choose for the optimal setting of the protocol to obtain the best trade off among complete tumor ablation and healthy tissue conservation, achieved with the optimal point on the Pareto front.