Publication

Abstract : Microwave hyperthermia has emerged as a potential supplement therapy for cancer treatment. The treatment modality elevates the temperature of cancer cells within the therapeutic limit (40 °C–45 °C). This will help to enhance their receptiveness to conventional treatments such as chemotherapy and radiation therapy. Numerical simulation strategies are adopted in this paper to simulate the effects of electromagnetic radiation on cancer cells. Combining electromagnetics and transient thermal analyses through a multiphysics approach, the thermal effects of electromagnetic (EM) radiation on the target cells are studied. A pentagonal patch antenna resonating at 2.45 GHz has been specially designed for this purpose and analysed experimentally. To mimic the breast tissues, a multi-layered simulation model has been designed with various sections such as skin, fat, fibroglandular tissue and tumor, positioned at different depths from the skin. The thickness of each layer is provided based on the average physiological measurements. To assure proper energy concentration at the tumor region, the electric field intensity and specific absorption rate are quantified through electromagnetic simulations. Subsequently, thermal simulations are performed in ANSYS Icepak by varying the input power levels of the antenna from 3 W to 10 W, to examine the therapeutic temperature developed at the tumor region. The effectiveness of thermal dosage is quantified with cumulative equivalent minutes at 43 °C (CEM43). Multiple simulations are performed by assuming varied positions of the tumor from the skin level, providing varied power levels accordingly. The proposed system acquires a rise in temperature to hyperthermia levels from the base temperature at a maximum rate less than 0.32 °C/s. Across the tested power levels, system attains CEM43 = 60 minutes for various tumor depths with tumor SAR≤ 40 W/kg and skin SAR<4 W/kg, falls under exposure limits. The proposed pentagonal patch antenna achieves faster therapeutic heating (<60 s) than prior antenna designs at 2.45 GHz with optimized power for varying tumor depths, keeping the skin temperature within the permissible limits.