Research and Education Newsletter v35- Internal - Flipbook - Page 6
Division of Radiation Oncology Annual Research and Education Newsletter: Fiscal Year 2020
Where Physics Meets Radiation
Oncology: Detecting DNA
Damage Induced by Carbon Ions
The fundamental principles of physics undergird the research and clinical applications of radiation therapy.
In the Department of Radiation Physics, faculty and professional staff are involved in conducting innovative
research; education and mentorship of students and residents; and clinical imaging, planning, and dosimetry.
RESEARCH
Gabriel Sawakuchi, Ph.D. is an associate professor in the
Department of Radiation Physics and co-leader of the Predictive
Biomarkers Pillar for the Radiation Oncology Strategic Initiatives
(ROSI). He has a special research interest in studying DNA
damage response caused by radiation. Collaborating with
an international group of physicists, engineers, biologists
and oncologists, Sawakuchi developed and published a new
technique for studying DNA damage from carbon ion therapy,
“Isolation of time-dependent DNA damage induced by energetic
carbon ions and their fragments using fluorescent nuclear track
detectors.” This was featured in the journal, Medical Physics,
as an Editor’s Choice article, and it also made the cover of the
January 2020 issue.
Carbon ion therapy is an emerging type of radiation therapy.
It may have the potential to reduce healthy tissue destruction
while treating cancer patients, especially those whose tumors
extent of DNA damage that can be caused by radiation, in order
to better adjust the radiation dose and time points of radiation
administration needed to overcome DNA repair and ultimately
kill cancer cells.
Sawakuchi and his team custom built an instrument that can
measure biological responses by imaging live cells and, at the
same time, physically follow the individual tracks of radiationinduced DNA damage in each cell with nanoscale spatial
resolution. Using this instrument, they discovered that the types
of DNA damage produced by high-energy radiation particles
associate with cell death.
To our knowledge, no other instrument of its kind has been
reported. This enables Sawakuchi and team to deftly navigate
and bridge the domains of biology, physics, and clinical
application. To extend their featured studies, these researchers
3D and Real-Time Imaging of DNA damage (green) and Radiation Particle Tracks (magenta) into Cells (from
McFadden et al. “Isolation of time-dependent DNA damage induced by energetic carbon ions and their fragments using
fluorescent nuclear track detectors”. Med Phys. 2020 Jan;47(1):272-281.
are resistant to other types of radiation therapy. DNA damage
from carbon ion therapy, as well as from other types of radiation
therapy, such as proton therapy, can be used as biomarkers to
monitor the effectiveness of radiation therapy and to provide
information on radiation dose and scheduling.
Because cells have a remarkable way of repairing DNA damage
and surviving, investigators sought to measure the types and
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are developing the next-generation 3D and real-time imaging
equipment to study the effects of radiation on neurons. The goal
is to develop clinical strategies to mitigate cognitive deficits
after radiation therapy. If proven successful, this work will help
broaden the application of radiation therapies and provide
patients with more treatment options.