Dr. John Barrett

John T. Barrett, MD, PhD

Chair, Radiation Oncology   
Professor of Radiation Oncology



John Barrett, MD, PhD, is chair of the  Department of Radiation Oncology at the Medical College of Georgia and medical director for clinical services at the Georgia Radiation Therapy Center, part of the Georgia Cancer Center.

Known as a strong patient advocate and effective communicator, Barrett works to ensure that MCG and the Georgia Cancer Center can continue to provide consistent and excellent care to people fighting cancer.

Barrett first joined the MCG faculty in 1992 after he completed his residency in radiation oncology and fellowship in medical oncology at the National Cancer Institute in Bethesda, Maryland. He left MCG in 2007 to serve as a radiation oncologist at the Watson Clinic Cancer & Research Center in Lakeland, Florida, before returning the medical school in 2017 as interim chair.

During his tenure as interim chair he grew the faculty — from one radiation oncologist to three and added more medical physicists, who work with radiation oncologists to help ensure the precision and accuracy of treatments. He also helped oversee a major renovation to the Georgia Radiation Therapy Center that included 8,000 square feet of new construction and provided new ambulatory care spaces and a new Helical Tomotherapy linear accelerator. Two of the older linear accelerators will be replaced with newer technology, Varian Truebeam machines.

Barrett earned his medical degree and his PhD in molecular biology and bacterial genetics from the University of South Carolina in Columbia.