Dennis R. Holmes, M.D. is a Board Certified dedicated breast surgeon at University of Southern California Norris Comprehensive Cancer Center where he serves as Director of New Technology Development and Director of Intraoperative Radiotherapy for the Breast Cancer Program. In this capacity, Dr. Holmes is only one of a few surgeons in the United States performing intraoperative radiotherapy following lumpectomy for the management of invasive breast cancer. Intraoperative radiotherapy permits the entire radiotherapy treatment to be given at the time of breast cancer surgery, as opposed to standard breast radiotherapy which is given as daily treatments for a 6-7 week period following surgery.

In addition to providing cutting-edge breast care, Dr. Holmes is Associate Director of the Breast Fellowship Program and Assistant Professor of Clinical Surgery at the U.S.C. Keck School of Medicine where he plays an active role in training future breast surgeons.   Dr. Holmes also serves as Chief of the Breast Section at LAC+USC Medical Center where he supervises the management of all breast cancer patients presenting for surgical care at the Los Angeles County Hospital. Dr. Holmes is a graduate of Tulane University School of Medicine, University California San Francisco-East Bay Surgical Residency, and the University of Southern California Breast Fellowship Program.  He is actively involved in breast cancer research, and serves as a principal investigator, co-investigator, or collaborator on multiple studies seeking to improve breast cancer prevention, diagnosis, and treatment.