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Steven N. Seyedin, MD

Steven N. Seyedin, MDAssistant Professor

Dr. Steven Seyedin is an Assistant Professor and Chief of the Genitourinary and Gastrointestinal Services in the Department of Radiation Oncology at UCI. Dr. Seyedin was an undergraduate at the University of California, Berkely, where he earned a Bachelor’s degree in Molecular and Cell Biology. He earned his Medical Degree from the David Geffen School of Medicine at UCLA before completing a research fellowship in radiation oncology at the MD Anderson Cancer Center in Houston. He subsequently completed residency training at the University of Iowa Hospital and Clinics where he received multiple accolades including the Roentgen Resident Research Award, UIHC Excellence in Clinical Teaching Award, and ASTRO Annual Meeting Resident Recognition Award in Biology.

Dr. Seyedin specializes in the treatment of cancers of the prostate, kidney, bladder, stomach, esophagus, pancreas, liver, anus, and rectum. As an expert in the use of stereotactic body radiotherapy for a variety of tumors, his research focuses on the integration of advanced technologies with systemic therapies to improve cancer care. He has developed active collaborations with laboratory investigators at UCI and has an interest in ushering new treatments to the clinic. Dr. Seyedin is a member of the NRG Oncology’s Colorectal Cancer Core Committee. A gifted educator who was recently awarded the Association of Residents in Radiation Oncology Educator of the Year award, Dr. Seyedin also serves Medical Student Clerkship Director for the Department of Radiation Oncology.



  • University of Iowa Hospital and Clinics, Iowa City, IA, 2020


  • University of Illinois College of Medicine, Chicago, IL, 2016


  • MD, University of California, Los Angeles, Los Angeles, CA 2014

Certifications and Memberships

  • American Board of Radiology, Radiation Oncology
  • Radiation Research Society
  • American Society of Clinical Oncology
  • American Society for Radiation Oncology
  • Radiologic Society of North America


  • ARRO Educator of the Year
  • ASTRO Annual Meeting Resident Recognition Award in Biology
  • UIHC Excellence in Clinical Teaching Award
  • American Brachytherapy Society HDR LDR Prostate Scholarship Workshop
  • RSNA Roentgen Resident Research Award
  • ASTRO Annual Meeting Abstract Travel Award
  • RSNA Roentgen Resident Research Award
  • David Geffen School of Medicine at UCLA Student Teaching Award

Selected Publications

  1. Seyedin SN, Ginader TG, Caster JM. The potential benefit of definitive focal therapies in select patients with metastatic esophageal cancer: A National Cancer Database Investigation. Ann Thorac Surg 2021; 112(2): 459-466.
  2. Seyedin SN, Gannon MK, Plictha KP, Abushahin LI, Berg DJ, Arshava EV, Parekh KP, Keech JC, Caster JM, Welsh JW, Allen BG. Safety and efficacy of stereotactic body radiation therapy for locoregional recurrences after prior chemoradiation for advanced esophageal carcinoma. Front Oncol 2020; 10: 1311.
  3. Seyedin SN, Callaghan CM, Mohiuddin I, Hawkes KL, Anderson CM, Buatti JM, Milhem MM, Monga V, Allen BG. The effect of concurrent stereotactic body radiation and anti-PD-1 therapy for recurrent metastatic sarcoma. Radiat Res 2020; 194(2): 124-132.
  4. Seyedin SN, Hasibuzzaman MM, Pham V, Petronek MS, Callaghan CM, Kalen AL, Mapuskar KA, Mott SL, Spitz DR, Allen BG, and Caster JM. Combination radiation therapy and PARP inhibition enhances responsiveness to anti-PD-1 therapy in colorectal tumor models. Int J Radiat Oncol Biol Phys 2020; 108(1): 81-92.

Office LocationContact Us

Department of Radiation Oncology

UCI Medical Center

  • UCI Chao Family Comprehensive Cancer Center

    101 The City Drive, Bldg. 23, Orange
    CA 92868-3298
    Fax: (714) 456-7170
  • UCI Health
  • UC Irvine Health School of Medicine
  • University of California Irvine