Radiation medicine at a crossroads: a historical perspective to consider future directions

Abstract As the world shut down in reaction to the COVID-19 pandemic in April 2020, many radiation oncologists began collaborating to revive a decades-old use of ionizing radiation therapy as a potential treatment for COVID-19 pneumonia. The concept of using low dose radiotherapy (LDRT) for a non-malignant disease based upon historical data proved to be highly controversial, but this debate has revived questions about the role of radiation therapy in medicine in ways that deserve deeper consideration .The aim of this paper is to provide some historical and scientific perspective on perceptions of radiation therapy and its risks, including questioning the linear no threshold (LNT) hypothesis and the emergence of data on radiation hormesis. The hope is that this review will stimulate debate on whether to expand the use of low dose radiotherapy (LDRT) beyond its current use primarily for neoplastic disease. Areas of interest include the potential roles of LDRT in the management of neurodegenerative, neuroinflammatory and autoimmune disease, and acute spinal cord injury.