WE‐A‐134‐10: Non‐Ionizing, Non‐Invasive, Non‐Contact, and Real‐Time Tumor Detection Using Ultra‐Wideband (UWB) Radar: A Feasibility Study

Purpose: We introduce a revolutionary tumor‐detection technology using the Ultra‐Wideband (UWB) radar. The UWB is electromagnetic pulses with around nanosecond width encompassing 3.1‐10.6 GHz. The UWB is well known in radar world as a through‐the‐wall imaging technology. We investigate penetration capability of the UWB through biological tissues to detect tumors. Methods: To experimentally demonstrate UWB penetration, our setup consists of transmitter/receiver radar system to measure the reflected signal off from the aluminum plate behind the biological tissues (pig skins, cow muscles, bones, fat, and wet‐sponges (lung‐substitute)). We perform a series of two complementary measurements: 1) a tissue sample with an aluminum plate under the tissue, 2) tissue only. The two measurements are subtracted to extract only the reflected signal from the aluminum back through the tissue to the receiver. Additionally, a phantom consisting of 0.2‐cm skin, 2.0‐cm fat, 0.5‐cm muscle, and 2.4‐cm wet sponge stacked in series was used as a miniature version of a human thorax. Instead of an aluminum plate, a 20‐ml water balloon (diameter=5 cm) was placed under the phantom to mimic lung‐tumor. Results: We confirm that the UWB can penetrate through all biological tissues with varying transmission. Specifically, the 1/e (36.7%) transmission depths from air to bone, fat, skin, muscle, and wet sponge are 1.52, 1.24, 0.09, 0.24, and 1.74cm, respectively. For the phantom‐tumor experiment, the reflected signal from the water balloon was detected with a SNR of ∼2 and its amplitude was reduced to 11.1% compared to the reflected signal measured without the phantom. Conclusion: The UWB is a revolutionary technology for tumor detection with multiple advantages including non‐contact, non‐invasive, non‐ionizing, real‐time, and low cost. This technology shows great promise as a real‐time sensing and imaging technique for radiation oncology.