Our medical physics team

Dr. Ronald McGarry reviews information with a medical physicist

In UK Radiation Oncology, our medical physicists and Certified Medical Dosimetrists (CMDs) work behind-the-scenes with our physicians to prepare an optimal treatment plan. These professionals rarely meet with patients directly but their work helps your physician make the best technical decisions for care and ensure the treatment is executed accurately.

Research and development

Our physicists play a pivotal role in our research team. They are involved in various developmental efforts to further improve treatment technology, find new procedures and more.


While our physicists and dosimetrists collaborate with our physicians to design the technical aspects of your treatment, they often are training future physicists, physicians, dosimetrists and others. It is our goal to provide the best treatment now and for years to come through the young professionals who are mentored by our physicists and physicians.

Ellis Lee Johnson, PhD, DABR

Director of Graduate Studies for Radiation Sciences
Professor and Clinical Medical Physicist

Clinical Interests

  • Treatment Planning
  • Radiation Dosimetry


Wei Luo, PhD, DABR

Associate Program Director for International Collaborations
Associate Professor and Clinical Medical Physicist

Clinical Interests

  • Routine plan/chart check
  • TrueBeam lead physicist
  • Brachytherapy
  • Overseeing patient-specific QA
  • Protocol physics coordinator


Dennis Cheek, PhD, DABR

Director of Medical Physics
Associate Professor

Clinical Interests

  • Brachytherapy
  • Radiosurgery


Damodar Pokhrel, PhD, DABR

Associate Director of Medical Physics Residency
Associate Professor and Clinical Medical Physicist

Clinical Interests 

  • Sterotactic radiosurgery/sterotactic body radiotherapy
  • Commissioning and quality assurance of new devices
  • Treatment plan optimization and motion management
  • Radiobiological modeling, treatment outcomes and uncertainty analysis
  • Brachytherapy
  • Gamma Knife


Quan Chen, PhD, DABR

Associate Professor and Clinical Medical Physicist

Clinical Interests

  • TomoTherapy
  • Motion Management
  • Breast Treatment


Sam Gerring, M.S.

Instructor and Clinical Medical Physicist

Clinical Interests

  • TomoTherapy
  • Quality Assurance


Tom Oldland, M.S.

Ashley Smith, PhD, DABR

Associate Professor