Dr. Ralph R. Weichselbaum

Dr. Ralph R. Weichselbaum, MD, is an internationally recognized radiation oncologist and physician–scientist specializing in molecular oncology and oligometastatic disease. He is the Daniel K. Ludwig Distinguished Service Professor and Chair of the Department of Radiation and Cellular Oncology at the University of Chicago. Dr. Weichselbaum earned his medical degree from the University of Chicago, completed residency training in radiation oncology at Stanford University, and pursued a research fellowship at the National Cancer Institute. He is board-certified in Radiation Oncology and is regarded as one of the foremost leaders in translational radiation research.

Dr. Weichselbaum’s research has advanced the biological understanding of how cancers metastasize, leading to the recognition and treatment of oligometastatic disease as a distinct clinical state. His laboratory has made seminal contributions in tumor biology, DNA damage response, and the interplay of radiation with immunotherapy. He has authored hundreds of peer-reviewed articles and has been principal investigator on multiple NIH grants and cooperative group studies. His work has influenced international standards for integrating radiation with systemic therapies in metastatic disease.

In addition to his research, Dr. Weichselbaum is a dedicated educator and mentor. He has trained generations of radiation oncologists and physician–scientists, many of whom hold leadership positions in academic medicine. He has served on editorial boards, NIH study sections, and national committees that shape the future of cancer research and care. Through his scientific leadership, clinical expertise, and mentorship, Dr. Ralph Weichselbaum continues to define and advance the field of radiation oncology.