About Us

We are committed to providing our clients with expertise, accuracy, and confidence.

Who we are

LinearPhysics, LLC is a national provider of medical physics consulting services to the radiation oncology market and partners with hospitals and oncology clinics. LinearPhysics’ expertise is the result of many years of clinical experience including treatment planning, TPS modeling, development of quality assurance protocols, data collection and testing.  We are dedicated to delivering the highest quality, most accurate, and thorough Commissioning and Quality Assurance services to the radiation oncology clinic.  Our physicists are highly trained, board certified experts who take pride in communicating well and delivering confidence to the clinical physicist and physicians.

What we do

Over the last 20+ years we have commissioned more than 100 linear accelerators, including all Varian, Siemens, and Elekta models. In the collection of data, we have utilized IBA, Sun Nuclear, and PTW scanning systems. We have measured data for Eclipse, Monaco, RayStation, and Pinnacle treatment planning systems.

LinearPhysics works globally, focused primarily in North America. We hold the additional required state licenses for Florida, Texas, New York, Virginia, and Ohio (CRE).

• Rigorous, thorough commissioning methodology

• Clear communication at every stage of the project

• Flexibility in scheduling, no downtime for your physicists

• Extensive experience with all major vendors

• Complete documentation of results

Patient safety is our ultimate goal. We provide accurate and tested data producing the most reliable representational model, and deliver confidence to you so you can offer the most accurate treatment to your patients.


Our team

Wm. Gary Shields

Founder and president of LinearPhysics, Wm. Gary Shields obtained his Master Degree from the University of Cincinnati in 1995 and became ABR Board Certified in Therapeutic Radiologic Physics in 2000.  His experience includes all aspects of clinical physics, dosimetry, patient and machine quality assurance, and regulatory compliance.  Gary has been commissioning discharging linear accelerators since 1994 having commissioned over 40 Varian TrueBeams and 15 Elekta Versa HDs all throughout the United States. In addition to his work on the first clinical Halcyon in the US, he has also worked internationally commissioning linear accelerators in Russia, Myanmar, and Columbia.  He is dedicated to his family and has a personal desire to provide the best possible care to all cancer patients.


                                                                                                 Carl Shields, PhD, Medical Physicist

"LinearPhysics was easy to work with from the start. Their personal attention and flexibility gave us the perfect commissioning experience. Our project from shielding, acceptance, commissioning, model validation, and finally end to end testing, gave us the "first day" treatment confidence that we needed."

 – Lisa DiBernardi, DVM, Diplomate ACVIM (Oncology), Diplomate ACVR (Radiation Oncology)

"Over the last ten years, they have accepted and commissioned eight of our linear accelerators. Each project started and ended on time, and stayed within budget. They communicated with us continually throughout the projects, always available in case we had questions. Our confidence in their work allowed our staff physicists to focus on other responsibilities."

-Paul Geis, Ph.D, Assistant Professor, Department of Radiation Oncology, University Hospitals Cleveland Medical Center


Call Us

(513) 282-3039

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