Conformal antenna applicator for mild hyperthermia of the breast

Summary form only given. According to statistics from the National Cancer Institute, an increasing rate of breast cancer in the US makes the treatment of cancers more important. Besides conventional treatments, chemotherapy (CT) and radiation therapy (RT), different techniques are also being used to increase the efficiency of CT and RT for breast cancer. Hyperthermia, also called thermotherapy, is an adjunctive therapy that can be paired with conventional treatments. This method exposes electromagnetic energy into the targeted tissue to raise the temperature up to 45 °C, which increases perfusion and drug delivery inside the cancerous cells. However, high input power and screening room requirements with long application time prevents hyperthermia from being applied in all clinics. Therefore, mild hyperthermia is experimented to make the process more applicable for patients. In this study, the goal is to observe the effect of low input power on tissue temperature at different depths of the breast with a shorter application time compared to current systems. Tissue temperature can be increased by 2-3 °C using this method. This technique will be applied by using a flexible microwave antenna applicator, which consists of 9 microwave antennas integrated in a circular-shaped PDMS, that is designed and fabricated. The breast can also be heated homogeneously with the located multiple antennas on the applicator. Six of the antennas are powered by an amplifier with a power divider, then it is attached on the breast mimicking gel. After that, fiber optic temperature sensors are placed at the depth of the gels and just under the surface. Measurements are taken of the temperature increase at the depth of 1 cm, with 1W power, at 450 Mhz without time limits while gradually increasing the power up to 5W. Thereafter, the depth is increased and the measurements are repeated at 2.5cm and 4cm depths for all power levels again with a limited time of 10 minutes. Design of- the flexible microwave antenna applicator and test results will be presented.