Gamma Knife (IMAGE) UT Southwestern Medical Center Caption Dr. Robert Timmerman (left), a radiation oncologist, prepares patient Katherine Coit for a procedure using UT Southwestern's Gamma Knife. Assisting are Drs. Karen Chang, medical physicist, and Steve Brown, neurosurgical resident. Credit UT Southwestern Medical Center Usage Restrictions none License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.