UCLA Journal of Radiation Oncology December First Edition - Flipbook - Page 7
UCLA RADIATION ONCOLOGY JOURNAL
NEW FRONTIERS
IN PROSTATE SBRT
Dr. Kishan is currently leading three clinical trials
to explore new frontiers in prostate SBRT
T
he thematic core of Dr. Amar
Kishan’s research is to improve
treatment efficacy and optimize
quality of life for men with prostate cancer.
He has approached this by developing an
active clinical and translational research
program. A major focus of his research
has been the use of stereotactic body
radiotherapy (SBRT) for prostate cancer.
This snapshot provides a brief overview
of this treatment as well as three exciting,
cutting edge clinical trials of SBRT for
prostate cancer that Dr. Kishan is leading
at UCLA.
SBRT for prostate cancer. UCLA's regimen
for SBRT involves five treatments with
radiation, delivered every other day -- this
is a nearly 90% reduction in the duration
of treatment and required visits. In 2019,
Dr. Kishan published a multi-institutional
consortium study that reported longterm safety and efficacy outcomes for
prostate SBRT in over 2000 patients.
This study is referenced in the 20W20
National Comprehensive Cancer Network
Guidelines, which note that SBRT is now
a standard of care option for patients who
are treated at experienced centers.
Historically, external beam radiation
therapy for prostate cancer has been
delivered in the form of small daily
doses of radiation over the course of as
many as 39-45 treatment sessions (eight
to nine weeks). We have since learned
that prostate cancer appears to be more
sensitive to higher doses of radiation
per day, suggesting that considerably
shorter durations of radiation therapy
may be, at the least, equally effective.
Simultaneous advances in technology
have allowed the safe and precise delivery
of larger doses of radiation in any given
session. A particularly advanced form of
external beam radiation therapy, known
as stereotactic body radiotherapy (SBRT),
involves the therapy of high doses per day
over the span of five or fewer treatments.
UCLA has been a global leader in studying
Dr. Kishan is currently leading three
clinical trials to explore new frontiers in
prostate SBRT. The first is the MIRAGE
(Magnetic Resonance Imaging-Guided
Stereotactic Body Radiotherapy for Prostate
Cancer) trial, which is a randomized trial
comparing standard CT-guided SBRT with
MRI-guided SBRT. The crux of this trial lies
in the visualization capabilities of various
radiation devices and the inherent motion
of the prostate. The prostate moves nearly
continuously due to internal anatomy
changes. Though these motions are small,
on the order of millimeters, radiation
delivery must be highly precise and even
millimeter motions must be accounted
for. While modern linear accelerators
are equipped with on-board CT scanners,
the prostate itself is not easily visualized
on a CT scan. Traditionally, targeting for
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