Tuesday, December 21, 2021, CLEVELAND, Ohio: The field of radiation cancer treatment needs to be brought into the precision medicine era, with patient-specific genomic data driving therapeutic decision-making rather than a one-size-fits-all approach, according to an expert from a top American hospital, Cleveland Clinic, and his team of collaborators.

Jacob G. Scott, MD, DPhil – a Cleveland Clinic radiation oncologist and associate professor at Case Western Reserve University School of Medicine – says that radiation oncology is lagging behind the field of medical oncology in leveraging recent advances in cancer genomics. He notes that radiation therapy is still largely prescribed by taking into account only the location of the cancer diagnosis or tumor to decide on standard dosing, assuming the biological effect will be the same across all patients, tumors and cancer types.

In an attempt to move the field forward, Dr. Scott and his collaborators from Case Western Reserve University School of Medicine and Moffitt Cancer Center in the U.S. have been working to demonstrate the benefits of a genomic-adjusted radiation dose (GARD) model for several years. They successfully devised and introduced the concept of adjusting the radiotherapy dose based on biological differences between or within tumors and published their proposed GARD paradigm in The Lancet Oncology journal in 2017.
Subsequently, in August this year, they published a study in The Lancet Oncology journal confirming the effectiveness of using GARD to maximize the therapeutic effect of a given physical radiotherapy dose. Dr. Scott, a member of the cancer research team at Cleveland Clinic, was first author on the study that validated the association between GARD and radiotherapy outcome in a large cohort of patients, across seven different cancer types.

This study used previously published data on cancers of the breast, head and neck, endometrium, melanoma, glioma, pancreas and lung to test the association between GARD, radiotherapy dose and patient outcomes using two endpoints: time to first recurrence and overall survival. Contrary to past assumptions, the study showed that the effect of radiation therapy on tumor response, toxicity, carcinogenesis and similar factors is not uniform across patients.

“As opposed to physical radiotherapy dose, which is the measure of what is delivered to the patient, GARD quantifies the biological effect on an individual patient of that delivered dose,” explains Dr. Scott. “What we found by looking at 1,600-plus patients is that the physical dose of radiation is not associated with outcome, but GARD is. It offers us a quantifiable parameter of the clinical effect of radiation.”

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