Establishing Universal Dose Guidelines in Radiation Oncology

A member of the Covenant Health cancer care team co-authored a study recently published in JACMP (Journal of Applied Clinical Medical Physics).

Photo of Dr. Ivan L. Cordrey
Ivan L. Cordrey, Ph.D., DABR , Senior Medical Physicist, CMC Cancer Center

Senior Medical Physicist at Cumberland Medical Center – Cancer Center, Ivan L. Cordrey, Ph.D., DABR, shares joint first authorship credit for the study: A measure of SRS/SRT plan quality: Quantitative limits for intermediate dose spill (R50%) in linac-based delivery. This work was first published on March 2, 2022.

Impact on Cancer Care

Many times, when laypeople attempt to read a scientific study, especially one within the field of medical physics, they may think they are reading a foreign language. The formulas, references, and medical terminology can be challenging to interpret for people who are not professionals within the field. It is difficult to understand how the study will impact or relate to their life or experiences. What difference will it make? For patients with cancer who undergo treatment in radiation oncology, studies like this one by Dr. Cordrey, et al, are quite important for improving patient care.

Scott Warwick, President and CAO of Thompson Cancer Survival Center, lauds this accomplishment, “As cancer care continues to advance and improve through new medications, technologies, and treatment techniques, we strongly desire to be a part of the solution. At Covenant, we encourage our cancer care team to be involved in developing and performing the research toward that end. Dr. Cordrey’s hard work and recent research publication support our long-standing mission to increase the number of cancer survivors in the communities we serve.”

Defining the Balance

In less technical terms, within radiation oncology, physicians, medical physicists, and dosimetrists must work to find a balance between delivering cure and unintended harm. The team finds and plans the way to deliver the most effective prescribed dose of radiation to the target treatment area (cancer) hoping to completely kill cancer. They must also be mindful to expose the surrounding healthy areas only to an amount of radiation that can be tolerated without detrimental damage.

Dose limit guidelines have been developed and set for most areas of the body, clearly indicating measures for radiation exposure toleration that must not be exceeded in a single treatment and over a lifetime. As the radiation oncology field advances and new treatment and delivery techniques are employed, new guidelines must be established and a new balance must be found.

New Guidelines

Dr. Cordrey and the co-authors published a peer-reviewed study to establish dose exposure guidelines for radiation when treating small cancers in a patient’s brain with stereotactic radiosurgery (SRT) and stereotactic radiotherapy (SRT). The specialized equipment capable of this kind of treatment is becoming more common in radiation therapy and will be installed at Cumberland Medical Center in the summer of 2022. The treatment delivery techniques on which this study focused are being used more frequently but there are no universal guidelines or ones that are widely accepted for limiting certain types of extraneous dose exposure.

Everyone working in the field knows radiation dose to non-target tissue must be limited, but questions remain. Such as:

  • How does one know if the radiation oncology treatment plan created at each facility is “good enough”?
  • How good is it reasonably possible for a treatment plan to be?
  • What is the clinically accepted range that defines “a good treatment plan”?
  • Or, perhaps more importantly, what ranges define what comes close to an “unacceptable” plan?

These are some of the fundamental questions this research answers.

Dr. Cordrey and his two collaborators, Dr. Desai of Chattanooga and Dr. Johnson of the University of Kentucky, hypothesized certain limits that would establish these guidelines based on their many prior published works that developed the basic science. They validated these proposed limits using several clinical data sets from respected academic medical centers and other sources along with their own data. In other words, they concluded their recommendations are valid.

The Published Work

Image shows the title, authors, and abstract of the study within the journal publication, Journal of Applied Clinical Medical Physics.
JACMP “A measure of SRS/SRT plan quality: Quantitative limits for intermediate dose spill (R50%) in linac-based delivery”

The article is available in the early view of the JACMP and will be in its next published edition. It is available now with open access (no charge) on the official website: or

This is the 8th publication in peer-reviewed journals for this group of collaborators in less than two years.  Dr. Cordrey and his co-authors plan to submit a 9th manuscript this week in response to reviewers’ comments.

Constantly Improving

Although the technical content of this study mainly appeals to other medical physicists and radiation oncologists, Dr. Cordrey’s endeavors are a less obvious example of living the Covenant Health “Pledge of Excellence”.  Seeking advances in cancer care and establishing safety guidelines are certainly ways to put the patient first, seek excellence, and establish Covenant Health and Thompson Cancer as the region’s first and best choice for patients.

Tom Rally, Director of Radiology and Radiation Oncology at Cumberland Medical Center and CMC Cancer Center, reaffirms the positive effects of Covenant Health’s continued investments in its cancer programs’ equipment and people. He says, “Some patients may wonder if they will have access to the most up-to-date treatment techniques if they choose to stay close to home for their cancer care. Covenant Health works to provide access to that care. Not only with top-notch equipment in their treatment facilities, but by encouraging the professional development of their employees. Not only does a patient being treated at Cumberland Medical Center and across Covenant have access to the best care, but they will be treated in a facility that is helping to define what cutting edge care will be in the future.”

Read the blog Thompson’s Experts: Mentoring the Future of Cancer Care to discover another example of the difference our team is making in medical physics, radiation oncology, and the future of cancer care. 

Use this link to explore the programs and services available at Thompson Cancer Survival Center. Click here to learn more about CMC Cancer Center.

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