Eliminating tumor cells through radiotherapy is like shooting down enemies
in a battlefield. Both need their mission completed with minimum collateral
damage. One thing infantrymen have learned over years of field operations,
however, is that real targets don’t stand still waiting to be shot;
they move. And so do tumor cells. Thanks to a $1.5 million grant by the
Henry L. Guenther Foundation, radiation clinicians at Torrance Memorial
Medical Center recently upgraded their armory with the new Varian TrueBeam®
slim linear accelerator, the latest “precision-guided munition”
to be used in the battle against tumor cells.
In 2013, Torrance Memorial became the first hospital in the South Bay to
treat cancers with TrueBeam. The grant funds the purchase of an additional,
slightly more advanced unit, which offers what can be described as a “GPS
tracking system” for pinpointing tumors.
“The most important new technology we are gaining with the new TrueBeam
unit is the Calypso® Extracranial Tracking System,” says Thyra
Endicott, MD, a radiation oncologist at Torrance Memorial. “By implanting
radiofrequency-activated markers within the target, Calypso enables us
to track tumor movements in real time during the treatment delivery.”
Variable and unpredictable, tumor movements are often caused by patient
movements or internal movement of the tumor within an organ, such as lung
or bladder. If these movements can be tracked, the radiation beam can
be made smaller to reduce the dose to adjacent normal tissue.
To minimize risk, the Calypso Tracking System monitors the whereabouts
of targeted tumor cells through uninterrupted radiofrequency signals from
electromagnetic transponders that are placed in the target lesion during
a simple outpatient procedure. It then interprets the target’s location
on lateral, longitudinal and vertical axes. With this objective information
on hand, the clinician can adjust the radiation beam at any time during
the procedure in accordance with the slightest change of the location
of the target cell. The system also automatically stops radiotherapy if
the target should move.
The TrueBeam series is known for its extraordinary precision and flexibility
in pinpointing tumors with the lowest exposure to surrounding healthy
tissues. It delivers radiation with a highly exact setup and very tight
Calypso improves TrueBeam’s clinical advantage of extraordinary preciseness
and accuracy. As a result, patients may experience fewer side effects.
The current TrueBeam linear accelerator at Torrance Memorial is used primarily
to treat brain tumors, cancer of the oral cavity and throat, and prostate
cancers. It is designed to treat a very limited volume. The new TrueBeam
will expand the ability to treat all types of tumors.
The Henry L. Guenther Foundation, the provider of the grant, is a private
charity foundation dedicated to preserving and enriching the benefits
of California residents, primarily those in Southern California. One of
its top priorities is expanding medical services. Supporting Torrance
Memorial with this latest advancement aligns perfectly with the foundation’s mission.