been highly successful in
prostate, gynecological, breast and several other types of cancer,” said
David Hall, marketing manager for Varian Medical Systems’ BrachyTherapy
business unit.
Breakthroughs for Permanent “Seeds”
Today, approximately 900 radiation oncology centers around the
world use Varian’s VariSeed™ treatment planning
software for guiding the placement of permanent prostate seed
implants in what is called low-dose-rate (LDR) brachytherapy.
Use of this technique alone or with external beam radiotherapy
is increasing for patients, including about 60,000, or one
third, of U.S. men who are diagnosed annually with prostate
cancer.
Physicians want to be certain they are delivering the intended dose. Varian’s
recent addition of dynamic dosimetry to its VariSeed software makes that easier.
With dynamic dosimetry, VariSeed maps out dose distributions as seeds are placed,
allowing physicians to make adjustments as they work. During the procedure,
the medical team uses ultrasound imaging with Varian’s new Twister™ 3D
data acquisition software to see the prostate and the seeds in three dimensions. “These
are breakthrough advances that will increase physicians’ confidence in
the accuracy of treatment delivery,” Hall said.
Advances in Temporary Seeding
High-dose-rate (HDR) brachytherapy delivers high-intensity radiation
directly into tumors through fine needles that are deployed
from computer-controlled afterloaders that move the radiation
source on a wire within the needle according to a prescribed
treatment plan. The total dose is delivered in a series of
fractions, or treatment sessions. Varian supplies VariSource™ and
GammaMed™ afterloaders, as well as BrachyVision™ treatment
planning software and applicators, for this therapy.
For cervical and endometrial cancers, Varian has introduced smaller titanium
applicators that are both easy to see in MRI and CT scans during the placement
and treatment planning process and more comfortable for the patient during
the course of therapy.
Varian also has added a Vitesse™ module to its BrachyVision software
to streamline prostate HDR brachytherapy, turning many treatments from overnight
hospital stays to outpatient procedures. With Vitesse, doctors can transfer
ultrasound images generated during needle placement directly into the BrachyVision
software, eliminating the need for CT scans, and making it possible to complete
a treatment plan within minutes. “In some cases, the first treatment
can be delivered almost immediately after the needles have been placed,” Hall
said. “Vitesse helps contain the cost of treatment and makes the experience
better for the patient.”
A New Use for Brachytherapy:
Breast Conservation
HDR brachytherapy is now also used to treat breast cancer. Today,
many women with breast cancer are successfully treated with local
surgery (“lumpectomy”), followed by a six-week course
of daily external beam radiation to the whole breast. Despite
the proven success of this approach, some women are turning to
a promising alternative: accelerated partial breast radiation.
Both IMRT and HDR brachytherapy are being studied as ways of
delivering accelerated partial breast radiation therapy, which
involves treating the area around a lumpectomy with a highly
localized dose of radiation over a period of about five days.
Debbie Vermeer, a radiation oncology nurse with young children, chose HDR brachytherapy
for her own treatment. “HDR brachytherapy took very little time, and
I was able to maintain a normal life,” she said.
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