IMPACT (IMplementation of x-ray PhAse-Contrast Tomography) Clinical Trial: Low dose Propagation-Based Phase-Contrast CT (PB-CT) for Breast Imaging in women 50-70 years old

The study will be a pilot study using Propagation-Based Phase-Contrast CT (PB-CT) (intervention) for breast imaging for the first time. This will be compared to the current standard of care which is mammography. This is because the current stage of the project is serving as a proof of concept and not as a diagnostic tool but the study will be eventually expanded once the initial results of the pilot study are analysed, and subsequently help inform how PB-CT contributes towards breast cancer screening, diagnosis, and treatment planning. Propagation-based CT (PB-CT) is an advanced type of imaging that creates incredibly detailed 3D pictures of the body. It uses X-rays, just like regular mammograms or CT scans, but it also captures the visibility of fine details, especially soft tissues or subtle changes that might not be seen on a standard CT scan. Standard imaging, such as mammograms and CT, relies on the absorption of x-rays through the body. However, PB-CT uses refraction as well as absorption of x-rays in tissue, and shows particular promise in breast imaging due to its superior sensitivity to soft-tissue tumours. This enables better-quality images to be obtained at lower radiation doses compared to conventional absorption-based CT imaging. The PB-CT scan takes 12-15 seconds for each breast, and the total set-up is expected to take less than 5 minutes. Participants will be asked to complete some surveys before and after the PB-CT scan, have the procedure explained to them before starting, and ask any questions so the total time spent at ANSTO may be 30 minutes. A research nurse and radiographer will go over consent with the participant. A radiographer will position and scan the participant with scientists and physicists in the console room. Radiologists will review the images after the scans are complete and processed. Prior to attending, participants will be screened by the research nurse to ensure they meet the inclusion criteria, including are they able to lie prone for a couple of minutes (to fulfil the scan), and if they have had a mammogram in the past 6 months. Access to their mammogram will be needed prior to attending for the PB-CT scan, and it will be used to compare to the PB-CT scan.