Correlation Between Dielectric Properties and Women Age for Breast Cancer Detection at 30 GHz

Breast cancer is the most common neoplasm in the female population, affecting a woman every eight during her life. The trend of incidence between 2003 and 2017 appears to increase slightly while mortality continues to decrease significantly. Early diagnosis increases the likelihood of having a cure able to overcome the disease, and for this reason mass screening programs are emphasized by all medical institutions. The purpose of screening is early diagnosis in a non-clinical phase. Currently, the reference diagnostic technique in senologic diagnosis is the X-ray mammography, principally for its good resolution. However, the woman exposition to ionizing radiation, as well as the requirement of unconfortable breast compression during the test, are pushing the interest toward new imaging techniques. In particular, the attention toward microwave and millimeter waves imaging systems for mass screening is increasing, as this solution could offer several benefits like the non-woman exposition to ionizing radiations. To this aim, a lot of studies have been done around the world, from microwave region to mm-wave frequencies. Starting from 2014, two extensive experimental campaigns have been performed at the European Institute of Oncology in Milan in a wide frequency range up to 50 GHz, involving more than 300 ex-vivo samples derived from around 100 women with ages spanning the range from 14 to 85 years. In this paper, considering the whole database derived from the two experimental campaigns, the correlation between the dielectric properties at 30 GHz of either healthy and tumorous tissues and the patient age, both at sample and women level, is presented. The results show that even at millimetre-wave frequencies a large fraction of the measured healthy samples exhibits dielectric properties compatible with an high adipose content, with a large contrast compared to the most of the tumorous samples, thus confirming the potential use of these frequencies for women older than around 40 years.