UCLA Journal of Radiation Oncology December First Edition - Flipbook - Page 9
UCLA RADIATION ONCOLOGY JOURNAL
Radiosensitivity Biomarker Influence
on Toxicity Following Prostate
Radiotherapy) trial, which is set to open
in late September 2020. While significant
side effects after modern radiation,
including SBRT, are rare, there are still
some patients who experience more
pronounced bothersome toxicity after
radiation than others. We currently do
not have the ability to reliably identify
patients who are likely to experience
significant toxicity because the factors
that govern the development of toxicity
remain largely obscure. Dr. Joanne
Weidhaas, the Director of the Division
of Molecular and Cellular Biology in the
UCLA Department of Radiation Oncology,
has long championed the theory that
certain genetic variants encoded within
the germline DNA—the DNA that is
present in all cells throughout the body
since birth—are likely to predispose
certain patients to more brisk radiation
reactions. Together with Dr. Weidhaas,
Dr. Kishan and collaborators at the Oslo
University Hospital in Norway have
identified biomarker panels encoded
within germline DNA that can reliably
predict which patients will develop
significant toxicity after either SBRT or the
longer course of radiation. Notably, these
panels appear to be specific to the form
of radiation delivered. That is, patients
at high risk of toxicity after SBRT are not
likely to be at high risk of toxicity after
the longer course of radiation, and vice
versa. Importantly, germline DNA is easy
to study because it can be analyzed from
blood draws or even a simple cheek swab.
The phase II GARUDA trial is designed to
reduce toxicity after SBRT by identifying
patients at higher risk beforehand and
modifying their radiation planning
process to mitigate this higher risk (for
instance, by altering the number of
treatments delivered). This should lead
to a substantial reduction in the number
of patients experiencing bothersome
toxicity after radiation. This trial is in the
final stages of initiation and is designed to
enroll 200 patients.
Overall, UCLA has been a leader in
prostate SBRT and Dr. Kishan is an expert
in this technique. The larger mission
of our department is not only to deliver
the highest quality of care, but to cut the
edge, innovate, and improve the standard
of care. These three trials are unique to
UCLA and are designed to do just that.
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