Lung cancer is the most common and deadly type of cancer globally, and survival is strongly linked to early detection. Therefore, it is highly desirable to screen high-risk individuals, and screening using computed tomography (CT) is currently the only method shown to improve survival. However, such screening is generally not carried out due to a high rate of false positives and increased patient x-ray exposure.
In this project we wanted to investigate the feasibility of using a CT system equipped with a unique, photon-counting silicon detector in screening for lung cancer. Advantages of the new detector include higher the resolution, no hard lower limit on the x-ray dose, reduced image artefacts, and higher contrast sensitivity compared to current CT detectors. Our hypothesis was that the patient x-ray dose can be significantly reduced in both lung cancer detection and characterisation. In addition, we believe that the higher resolution could reduce false positives, which would further reduce the dose through fewer follow-ups as well as lower the clinical costs and workload in screening. The use of photon-counting CT thus has the potential to simultaneously address both the main limitations currently making lung cancer screening infeasible.
Due to delays and unforeseen circumstances, scanning patients with lung cancer was not possible during the project. Instead, the potential clinical benefit of the improved resolution offered by the system was evaluated for head and neck scans. The main conclusions from the project were that the developed prototype system was suitable for patient scanning, offered better resolution than current hospital scanners, and that the improved resolution was deemed by clinicians to have clinical value in head and neck scans.
