GALWAY, Ireland/PRNewswire/
— Soft tissue imaging with 3D ultrasound both at therapy simulation and
just before treatment has transformed prostate radiotherapy at University
Hospital Galway (UHG). The majority of radiotherapy patients with prostate
cancer who visit the clinic will benefit from a new technology that can
accurately track the prostate’s position before each treatment. The Elekta
Clarity® 3D system provides ultrasound-assisted image guidance to radiation
therapy (IGRT), and avoids the additional radiation dose that comes with other
IGRT techniques.
“The big advantage of Clarity is you’re not adding any
radiation dose – you’re getting pictures of the prostate for ‘free,'” says
Margaret Moore, UHG’s Head of Radiation Physics. “For planning treatments,
CT simulation and Clarity are a great combination. Both modalities add their
bit of intelligence to create the certainty that you’re seeing the
target.”
Reliably localizing the prostate is critical as its position
can change due to bladder and rectal filling, in addition to patient breathing,
she adds.
“If you aim the treatment beams at the same spot every
day, but the anatomy you want to treat is moving in and out of the spot, then
it’s not getting the full dose it should,” Ms. Moore explains.
“Clarity allows us to track the prostate’s position before each treatment,
and keep the treatment beam on target.”
UHG, which opened clinically in 2005, acquired Clarity in
2008 and began using it with one of its three linear accelerators. Clarity is
capable of integrating with any external beam radiation therapy workflow and
equipment to support simulation, planning and treatment.
“In the equipment evaluation, we liked the idea of
matching the planning ultrasound to the treatment room ultrasound that Clarity
offered,” Ms. Moore recalls. “Other similar IGRT options try to match
ultrasound to CT, which could affect alignment accuracy. Clarity also wouldn’t
require reconfiguring our linear accelerator – we could integrate the system
easily.”
Versatile Clarity
Radiation oncologists at UHG have been able to use Clarity routinely to
fine-tune prostate contouring, superficially at the bladder junction.
“In some cases, the lobes of the prostate reach up to
the bladder, so distinguishing bladder tissue from prostate tissue is difficult
using CT,” Ms. Moore observes. “On ultrasound, there’s a huge
difference. The bladder is much more distinctive than the prostate gland.”
Clarity has been also been indispensable in facilitating
soft tissue imaging of prostate cancer patients with single or bilateral hip
prostheses, Ms. Moore adds.
“The metal in artificial hips soaks up the planning CT
imaging dose, which creates an artifact that blocks out the view of the
prostate and prevents contouring,” she says. “Ultrasound is
unaffected by these implants. Clarity is our savior for planning these
patients.”
Learn more at www.elekta.com/clarity.