Cancer radiation therapy:

Cancer is the uncontrolled growth of
abnormal cells in the body. Cancerous
cells are also called malignant cells.

Medical isotope specialist IsoRay
(Richland, WA) has completed a
licensing agreement to become the
exclusive worldwide distributor of the
GliaSite brachytherapy system – a
balloon catheter device used in the
treatment of brain tumors.

Brain tumors often prove difficult to
remove completely because of the
need to avoid damaging the brain.
Typically, surgeons remove as much of
the tumor as possible and then treat
the surrounding areas with radiation
therapy. The GliaSite system, a form of
intracavitary brachytherapy, provides a
means to target the radiation directly
to such sites.

By inserting the balloon catheter into
the surgical cavity and inflating it with a
specified high dose of a liquid radiation
source, the radiation is delivered to
those areas most likely to still harbour
cancer cells. The radioactive liquid is
introduced around one week after
surgery, and the balloon remains
inflated for several days until the
required dose has been delivered and
the isotope is then withdrawn. The
method is also less likely to damage
healthy brain tissue than external-
beam radiotherapy.
The GliaSite system, which IsoRay has
licensed from women's health
specialist Hologic (Bedford, MA), has
previously been used to treat
approximately 500 cases per year at
some 40 hospitals worldwide. To date,
Iotrex (iodine-125) has been used as
the liquid radiation source; however,
IsoRay ultimately plans to market the
GliaSite with its proprietary isotope
caesium-131 (Cs-131).

"Most cancerous brain tumors reoccur
shortly following removal, and the
cancer tends to return near the site of
the original tumor. Brain cancer is one
of the fastest growing cancers and
recurrence often proves fatal,"
explained Dwight Babcock, CEO of
IsoRay. "Because brain cancer is so
fast growing, liquid caesium-131 offers
added benefits because it has a higher
energy and delivers it five times faster
than Iotrex."

Varian's Trilogy system: combines the
capabilities of other external beam
radiation technologies -- including
Cyberknife, Tomotherapy, and Novalis
it can treat tumors in the brain, spine,
lung, liver, prostate and pancreas;

CyberKnife is a system that treats
cancer by beaming large doses of
radiation into tumors. It is designed to
kill the tumors without surgery, making
some treatments outpatient
procedures. The device has been on
the U.S. market since 1999 and is also
approved in Europe, Korea, and Japan.

Accuray founder John Adler is joining
Varian Medical  and it is thought that
Adler's experience will make the
company a tougher competitor for
Accuray. Adler, 55, developed the
CyberKnife system in 1987, and
worked at Accuray from 1991 to 2009.
He is also a past chairman and CEO of
the company.