Dr. Peter George Ehrnstrom, MD

Dr. John Halligan is the medical director for radiation oncology at the Providence Cancer Center. Dr. Halligan has over 14 years of experience in treating all types of cancer with radiation therapy. Before coming to the Providence Cancer Center, he worked the past 10 years for Madigan Army Medical Center in Tacoma, WA, where of those years he was chief of Radiation Oncology Services for the last four years. He was also on staff at the University of Washington Medical Center and a clinical assistant professor at Overlake Hospital in Bellevue, WA. Prior to this experience he worked for three years at Walter Reed Army Medical Center and for two years as a brigade surgeon and flight surgeon for the United States Army Berlin Brigade in Berlin, Germany. Dr. Halligan received his medical training from the Uniformed Services University of Health Sciences in Bethesda, Maryland. He completed his residency in radiation oncology at the University of Washington Medical Center. Dr Halligan is board certified by the American Board of Radiology.