Dr. Tsien is Professor of Radiation Oncology at Washington School of Medicine. She is Chief of Central Nervous System (CNS) service, Director of Clinical Research for Radiation Oncology, and Co-Medical Director of the Stereotactic Radiosurgery Program and the Gamma Knife Center. She is a co-leader of the Neuro-Oncology program at the Siteman Cancer Center at Barnes Jewish Hospital. In 2014, Dr. Tsien joined the faculty of Washington University School of Medicine. She was previously a faculty member of the Department of Radiation Oncology at the University of Michigan, Ann Arbor, where she was chief of the CNS service and co-director of the stereotactic radiosurgery program. Dr. Tsien received her medical degree from McGill University Faculty of Medicine located in Montreal, Canada. She then went on to complete her residency in radiation oncology at McGill University Health Center as well as a fellowship at the University of Michigan. Her clinical practice and research interests include the treatment and management of brain tumors, stereotactic radiosurgery, proton therapy and advanced MR and PET imaging biomarkers of response in brain tumors.