PHOTODYNAMIC THERAPY (PDT)

Photodynamic therapy is a procedure that
involves the use of both a laser and a sensitizing
drug. Just prior to surgery, the drug is injected
into a vein or artery where it travels through the
bloodstream and is absorbed by the tumor. The
drug contains a special compound that causes
tumor cells to appear a fluorescent “glowing
green.” During surgery, the neurosurgeon aims
the laser at the tumor, which activates the drug
and kills the tumor cells.

This type of therapy does have limitations.
• Only tumors that are considered operable
can be treated with this method.
• Only tumor cells that are visible to the
neurosurgeon can be identified and treated
using the sensitizing drug. Portions of a tumor
may be hidden and not susceptible to light.
• Some tumors will not respond to the
sensitizing drug.
• Tumors near the brain stem cannot be treated
with this method due to the risk of swelling
that might occur.