Design of Hyperthermia Applicator to Heat Multi-Brain Tumors Simultaneously Based on Adaptive Beamforming Technique

Recently, hyperthermia therapy is considered as one of the key treatment principles due to its importance and effectiveness in healing the deep-seated tumors. However, for brain tumors, it is difficult to heat due to high perfusion and thermal conductivity of the head. Therefore, in this research, the technique of non-invasive heat focalization in multiple tumors, simultaneously, without affecting healthy tissue based on adaptive beamforming was investigated and presented. It is done by controlling the feeding of the antenna array surrounding the brain using a modified hybrid version of gravitational search algorithm and particle swarm optimization (MGSA-PSO). An antenna system in the form of a head helmet was designed and evaluated with 48 antenna elements each of them has a separate excitation that controls the field intensity and beamforming direction towards the tumors. Many scenarios considering a single tumor in different positions with different volumes or multiple tumors are studied to evaluate the performance of the applicator. The helmet was tested on the challenging scenario of a very mature and dense brain with realistic thermal and dielectric properties. The results confirmed the ability of the helmet technology and the proposed antenna system to use a microwave power of 65 W to lift the neoplasm temperature to over 42 °C while keeping healthy tissue safe at 37 degrees with none hot spots. Furthermore, the results showed the capability of the proposed model to treat multiple tumors simultaneously.