The Oncology Institute logo

Geoffrey Geiger, M.D.

Senior Medical Director, Radiation Oncology
Geoffrey Geiger 4 14 2024
Rated 5 / 5 stars

Languages Spoken



Covina Radiation Oncology
(626) 331-6866

554 East San Bernardino Rd.
Suite 105
Covina, CA 91723

(626) 331-6773
Downey Radiation Oncology
(626) 331-6866

10226 Lakewood Blvd.
Downey, CA 90241

(626) 331-6773


American College of Radiation Oncology

Hospital of the University of Pennsylvania
• Radiation Oncology

Medical Education
University of Pennsylvania
• Doctor of Medicine


Dr. Geiger joined TOI in 2024, bringing significant clinical and research expertise, having contributed to numerous abstracts and journal publications on radiation therapy and cancer treatments. Before coming to TOI, Dr. Geiger was the medical director of GenesisCare’s Southernmost cancer center in Key West, Florida.

Dr. Geiger brings significant clinical and research expertise to TOI, contributing to numerous journal publications on radiation therapy and cancer treatments. He has presented this data at several national and international meetings and authored several textbook chapters. He is currently an Associate Professor of Radiation Oncology at the University of Central Florida College of Medicine. He brings special expertise in proton therapy, brachytherapy, and stereotactic radiosurgery, having worked extensively with CyberKnife and Gamma Knife radiosurgery platforms. He has also worked extensively with the United States Department of Defense as a consultant/contractor for his expertise in radiation effects on humans.

His special interests include the treatment of brain, head and neck cancers, skull base tumors, and skin cancers, as well as gynecological cancers, genitourinary, and gastrointestinal malignancies. He completed his medical school training at the University of Pennsylvania School of Medicine and his internship and residency at the Hospital of the University of Pennsylvania in Philadelphia before joining the faculty there as an Assistant Professor of Radiation Oncology from 2012-2017, where he was the only faculty member simultaneously treating patients with both x-ray and proton radiotherapy, brachytherapy, as well as CyberKnife and Gammaknife radiosurgery. When not treating cancer patients, Dr. Geiger is a musician, an avid photographer, both above and below water, and a Master Scuba Diver.

Certifications & Awards

  • Diplomate, American Board of Radiology (Radiation Oncology)
  • UPHS Proton Certification Course
  • Certification, TORS Surgical Course, American Head & Neck Society (AHNS)
  • Principles and Practice of Gamma Knife Radiosurgery, University of Pittsburgh Full Body CyberKnife Training
Skip to content