Dr. Johnson obtained his MD degree from the Medical College of Virginia. His post-doctoral studies included Internal Medicine internship at Wilford Hall USAF Medical Center in San Antonio, Texas, followed by Radiation Oncology residency at Stanford University Medical Center. From 1983-87, he served as the Chairman of Radiation Oncology at the David Grant USAF Medical Center in California. He subsequently completed both USAF Air Command & Staff and Air War College post-graduate degrees, and retired as a Colonel in the USAF reserves in 1999, having served as a Radiation Oncology Consultant, Flight Surgeon, and Commander of David Grant USAF Medical Center. In 1987, Dr. Johnson was a founding member of the Florida Radiation Oncology Group (FROG) in Jacksonville, Florida, where continued his clinical practice for 30 years.
Dr. Johnson was Chief of Radiation Oncology at Baptist Medical Center Jacksonville from 1995-2003, Chairman of the Institutional Review Committee there from 2001-2004, and Chief of Staff at the Medical Center from 2004-06. He has been the Vice-President–Programs for the American Cancer Society in Duval County, and served as Vice President for Clinical Affairs for the national Oncure Medical Corporation from 2011-13. Dr. Johnson is Board Certified in both Radiation Oncology and Hospice and Palliative Care Medicine, and has held two faculty appointments: first with Stanford University as a Clinical Instructor in Radiation Oncology, and currently as an Assistant Professor of Oncology with the Mayo Medical School.
Dr. Johnson has a major interest in clinical cancer research, having been a Principal Investigator for the Radiation Therapy Oncology Group and Children’s Oncology Groups, and for 28 years headed up the FROG and Oncure research programs. His clinical interests include stereotactic radiosurgery, prostate brachytherapy, breast, and pediatric cancers, as well as early lung cancer detection via breath analysis. He serves on national research strategy committees and has authored numerous protocols, as well as over 60 scientific publications. Dr. Johnson and his group have successfully developed integrated cancer clinics in small communities and were founders of the Integrated Community Oncology Network in northeastern Florida. He has also served as a Quality Control consultant to the Nuclear Regulatory Commission, and as a member of the Radiation Therapy Alliance, providing the Centers for Medicare & Medicaid Services with novel strategies for clinical cancer care payment bundling.