CONVECTION ENHANCED DELIVERY ( C E D )

One of the newest methods of delivering
chemotherapy drugs or biologic therapies
to a tumor is CED, or “convection enhanced
delivery.” CED uses the principles of constant
pressure to “flow” or “infuse” substances
through brain tumor tissue. The procedure
begins with a surgery, during which a catheter
(or multiple catheters, depending on the tumor
size) is placed into the tumor area. The
neurosurgeon then connects a pump-like
device to the catheter, filling it with the
therapeutic substance. The fluid then flows, by
use of pressure and gravity, through the tumor
area. This “bulk flow” or “convective-delivery”
method bypasses the blood brain barrier,
placing the therapeutic substance in direct
contact with tumor tissue.
Clinical trials are exploring the use of CED
as a way of placing immunotoxins, radioactive
monoclonal antibodies, and various
chemotherapy drugs at the tumor site.
As this technique is developing, researchers
are simultaneously exploring ways to include
“tracers” in the substances flowing into the
brain. Those tracers can be viewed on an MRI
scan performed during CED, and may allow
researchers to make real-time observations of
the movement of therapeutic substances in and
around the tumor. Research is also underway to
predict the flow pattern that will occur after
catheter placement.