Dr. Mastras earned his bachelor’s degree from Lehigh University and his medical degree from University of Vermont. He completed his postgraduate training at University of Hawaii and University of Washington Medical Center and was certified by the American Board of Radiology. Dr. Mastras joined Tacoma Valley Radiation Oncology Centers in 1993. Dr. Mastras is board certified. He holds medical staff privileges at Tacoma General, Good Samaritan, Allenmore, St. Joseph, St. Francis and St. Clare Hospitals as well as Auburn General Hospital He holds memberships in multiple medical societies including the Pierce County Medical Society, Washington State Medical Association, the American Society for Therapeutic Radiation and Oncology, American College of Radiation Oncology, Western Association of Gynecologic Oncologists, and the American Medical Association.