The Future of Cancer Therapy with X-rays: Patient Numbers, Innovations, Clinical Trials, and the Problem of Generating Evidence

When Roentgen discovered the X-rays 125 years ago, his finding was soon recognized as a breakthrough in research and awarded with the Nobel Prize. Today X-rays are widely used in natural and applied sciences and even art. In medicine, X-rays have made an impressive impact far beyond their original domain of diagnostic imaging. In cancer treatment, X-rays are indispensable for reaching the goal of uncomplicated and lasting tumor control. Using the possibilities of modern technology and the innovative mind of physicians and physicists, definitive cancer cure cannot only be achieved by combination of surgery and radiation, but also by radiotherapy alone. One prominent example is the application of single high radiation doses with optimal geometrical precision through image-guided stereotactic radiotherapy. The article aims to highlight past, current, and future sustainable developments in oncology in general, but in radiation oncology, especially. We discuss the very complex challenge of generating evidence by clinical research. In this context, the tumor registries play a very important role. The data of tumor registries and the results of clinical studies demonstrate the benefit for cancer patients who experienced individualized radiotherapy. For cancer cure, it is most important to treat in an early, localized stage of the disease.