Optical imaging for screening and early cancer diagnosis in low-resource settings

Low-cost optical imaging technologies have the potential to reduce inequalities in health care by improving the detection of precancer or early cancer and enabling more effective and less invasive treatment. In this Review, we summarize technologies for in vivo widefield, multi-spectral, endoscopic and high-resolution optical imaging that could offer affordable approaches to improving cancer screening and early detection at the point of care. Additionally, we discuss approaches to slide-free microscopy, including confocal imaging, light-sheet microscopy and phase modulation techniques, that can reduce the infrastructure and expertise needed for definitive cancer diagnosis. We also evaluate how machine learning-based algorithms can improve the accuracy and accessibility of optical imaging systems and provide real-time image analysis. To achieve the potential of optical technologies, developers must ensure that devices are easy to use, the optical technologies must be evaluated in multi-institutional, prospective clinical tests in the intended setting, and the barriers to commercial scale-up in under-resourced markets must be overcome. Therefore, test developers should view the production of simple and effective diagnostic tools that are accessible and affordable for all countries and settings as a central goal of their profession.